More Problems with Criminal Trials: The Limited Effectiveness of Legal Mechanisms
MORE PROBLEMS WITH CRIMINAL TRIALS: THE LIMITED EFFECTIVENESS OF LEGAL MECHANISMS
DAN SIMON 0 1
0 Copyright © 2012 by Dan Simon. This article is also available at
1 Professor of Law and Psychology at the University of Southern California. For helpful Northwestern Law School, The University of Chicago Law School, USC Gould School of Law, and Yale Law School. I am particularly grateful for contributions by Bruce Ackerman , Akhil Amar, Jack Balkin, Rebecca Brown, Steve Clark, Mirjan Damaška, Shari Diamond, John Donohue, Brandon Garrett, Heather Gerken, Phil Heymann, Sam Gross, Dan Kahan, Dan Klerman, John Langbein, Tom Lyon, Rob MacCoun, Richard McAdams, Daniel Markovits, Tracey Meares, Janice Nadler, Charles Ogletree, Robert Post, Carol Steiker, Kate Stith, Alan Stone, Lloyd Weinreb , and Jim Whitman. For their wonderful assistance, I thank the staff of the library at USC Law School. My deepest gratitude goes to Anne Simon. 1. ROBERT P. BURNS, THE DEATH OF THE AMERICAN TRIAL 3 (2009); JAMES BOYD WHITE, FROM EXPECTATION TO EXPERIENCE: ESSAYS ON LAW AND LEGAL EDUCATION 108 (1999). 2. Randall T. Shepard , The New Role of State Supreme Courts as Engines of Court Reform, 81 N.Y.U. L. R , USA
This article follows in the heels of an article entitled The Limited
Diagnosticity of Criminal Trials (Limited Diagnosticity).5 Both articles pertain
to parts of a larger critique of the criminal justice process that will be published
in a book manuscript In Doubt: The Psychology of the Criminal Justice Process
(In Doubt).6 Limited Diagnosticity examined how good fact finders are in
determining facts from the types of evidence presented in criminal trials. In
other words, how well do juries and judges perform the diagnostic function of
distinguishing between factual guilt and innocence? To address this question,
that article applied a body of experimental psychological research pertaining to
the performance of the tasks involved in the adjudicatory process.7
As suggested by its title, Limited Diagnosticity concluded that the cognitive
processing involved in discovering the truth in difficult cases is more complex
and less reliable than generally believed.8 One problem with the diagnosticity of
criminal adjudication stems from the fact that the evidence that is typically
presented in criminal trials is of uneven, and often low, quality. The problems
with the integrity of the evidence begin with the fact that criminal investigations
are not conducted through best-practice procedures. Courtroom testimony is
usually proffered months, sometimes years, following the criminal event, a
period during which witnesses repeatedly interact with the criminal process and
are subjected to a variety of contaminating sources. As a result, the “raw
evidence” perceived by the witness at the criminal event often undergoes
editing, embellishment, and alteration. Determining the facts accurately from
this “synthesized evidence” is a daunting task, especially given the opacity of
the investigative process.
Second, the research examined in Limited Diagnosticity indicated that even
if the evidence was reliable, drawing the correct inferences from the most
common types of evidence presented in criminal trials is a difficult feat. People
have a difficult time judging whether a witness identified the perpetrator
correctly, whether a witness’s memories of an event are accurate, and whether
confessions obtained in police interrogations offer truthful accounts of the
suspect’s deeds. The research also indicated that alibi testimony can be hard to
produce and is often misleading, and that detecting deceit from people’s
WRONG (2011); Samuel R. Gross et al., Exonerations in the United States 1989 Through 2003, 95 J.
CRIM. L. & CRIMINOLOGY 523, 523–24 (2005); 250 Exonerated: Too Many Wrongfully Convicted, THE
INNOCENCE PROJECT 1 (2010), http://www.innocenceproject.org/docs/InnocenceProject_250.pdf.
5. Dan Simon, The Limited Diagnosticity of Criminal Trials, 64 VAND. L. REV. 143 (2011).
6. DAN SIMON, IN DOUBT: THE PSYCHOLOGY OF THE CRIMINAL JUSTICE PROCESS
(forthcoming 2012) (on file with author).
7. The following discussion focuses almost exclusively on determinations of facts that are, at least
in principle, discernable—notably, the identity of the perpetrator and the physical acts and
circumstances of the criminal event. This article has little to say about value judgments that fact finders
are called to make, such as the reasonableness of an act, the morality of a behavior, or the fairness of
8. This project pertains primarily to the class of difficult cases, in which the evidence relies mostly
on human testimony and is factually complex. These are the cases that consume most of the
adjudicative resources and that put the diagnostic capabilities of the trial to the test.
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demeanor is often mistaken.
Third, the fact finding task is further hindered by a variety of factors that are
inherent to the environment of criminal trials. These include the excessive
persuasive attempts by lawyers, exposure to extra-evidential information, the
emotional arousal that accompanies many criminal trials, and racial stereotypes.
Another hindrance stems from the fact finder’s cognitive process itself, namely,
the “coherence effect.”9 Fact finders tend to overestimate their performance on
the fact finding tasks and to underestimate their susceptibility to biasing factors.
In sum, Limited Diagnosticity concluded that factual findings in criminal trials
are bound to contain an appreciable level of inaccuracy and they are also
vulnerable to manipulation. While faulty factual determinations can result in
dropped charges against truly guilty people and even wrongful acquittals, they
lead mostly to the prosecution of innocent people. The prospect of error is
generally ignored or denied by those entrusted with governing the criminal
justice system, and is not adequately recognized in the scholarly debate. It
should be noted that these findings pertain to actors who honestly believe that
they are fulfilling their roles properly. Deliberate dishonest conduct raises
different sets of issues, which lie beyond the scope of this project.10
One possible objection to Limited Diagnosticity is that it was confined to
human performance in decontextualized circumstances that fail to capture the
potential for accuracy afforded by the legal procedure. Criminal fact finding
might prove to be more diagnostic once embedded in the legal mechanisms that
have been designed to correct for errors and to promote accuracy. This article is
intended to explore that possibility. It examines the psychological research on
the potential of a number of prominent components of the criminal trial to
promote the accuracy of the fact finding task. These mechanisms include
crossexamination, jury instructions, jurors’ assurances of impartiality, the
prosecution’s heightened burdens, jury deliberation, and judicial review by
appellate and post-conviction proceedings. The ubiquitous reverence of the
American criminal trial is premised on the assumption that these mechanisms
perform their designated functions successfully. The truth evincing potential of
these mechanisms is the subject of this article, and they will be examined in
turn. In all, the article paints a rather mixed and overall troubling picture. To a
9. See generally Dan Simon, A Third View of the Black Box: Cognitive Coherence in Legal
Decision Making, 71 U. CHI. L. REV. 511 (2004); Dan Simon & Kieth J. Holyoak, Structural Dynamics
of Cognition: From Consistency Theories to Constraint Satisfaction, 6 PERSONALITY & SOC. PSYCHOL.
REV. 283 (2002); DAN SIMON, supra note 6, at chs. 2, 6.
10. The article will focus mostly on the performance of lay people who serve the fact finding
function in the large majority of criminal trials. Its purpose, however, is not to question the suitability of
juries for the task, nor to compare them to judges. A mounting body of studies finds that judges do not
perform much differently from lay people in many fact finding tasks. See, e.g., Chris Guthrie, Jeffrey J.
Rachlinski & Andrew J. Wistrich, Inside the Judicial Mind, 86 CORNELL L. REV. 777, 826–27 (2001);
Jeffrey J. Rachlinski, Chris Guthrie & Andrew J. Wistrich, Inside the Bankruptcy Judge’s Mind, 86 B.U.
L. REV. 1227, 1256–57 (2006). The limitations of human cognition observed in the research appear to
exceed any possible differences between the two decisionmaking entities. The suitability of the jury as
the preferred fact finding body is left for another day.
limited extent, these mechanisms do indeed enhance diagnosticity, but under a
range of realistic circumstances, they turn out to be ineffective, and even
detrimental to the process.
The cross-examination of a witness in open court is heralded as a one of the
hallmarks of the adversarial system.11 In addition to its important symbolic and
political dimensions, cross-examination is deemed a formidable tool for the
discovery of truth. The method has long been believed to “beat and bolt out the
Truth.”12 Quoting John Wigmore, the Supreme Court has repeatedly stated that
cross-examination is the “greatest legal engine ever invented for the discovery
of truth.”13 Cross-examination is closely related to the principle of orality, a
central feature of the Anglo-American criminal trial by which testimony is
given live, in open court.14 The cross-examination of witnesses could
conceivably improve the diagnosticity of the process by either deterring or
exposing false testimony.
First, cross-examination could have a prophylactic effect on would-be
witnesses. The expectation of having to face tough questioning in open court
could indeed have a harnessing effect on witnesses throughout the investigative
process and trial in that the fear of exposure could deter witnesses from
providing dishonest statements.
Still, the limits of this effect ought not be overlooked. For one, the deterrent
effect might restrain would-be liars, but it is doubtful whether it can make much
impact on the more challenging cases that involve honest, yet mistaken,
witnesses. Memory research indicates that people tend to trust their memories,
regardless of the accuracy of those memorial accounts.15 Given that mistaken
witnesses perceive themselves to be accurate, they are unlikely to be deterred
from recounting their (actually false) memories any more than accurate
witnesses would be deterred from recounting their (truly correct) ones.
The deterrent effect is likely to be diminished also when the witness has
little to fear from being exposed on the stand. Witnesses have little to fear when
11. The right to cross-examination is one of the primary justifications for the right to confront
one’s witness and the right to assistance of counsel, both guaranteed by the Sixth Amendment, which
reads in part, “In all criminal prosecutions, the accused shall enjoy the right to . . . be confronted with
the witnesses against him . . . and to have the Assistance of Counsel for his defence.” U.S. CONST.
12. JOHN H. LANGBEIN, THE ORIGINS OF ADVERSARY CRIMINAL TRIAL 234
(A. W. Brian
Simpson ed., 2003)
(quoting Matthew Hale).
13. See, e.g., Lilly v. Virginia, 527 U.S. 116, 124 (1999); Watkins v. Sowders, 449 U.S. 341, 349
14. See Washington v. Crawford, 541 U.S. 36, 43 (2004); Honoré, T., The Primacy of Oral
Evidence? in CRIME, PROOF AND PUNISHMENT: ESSAYS IN MEMORY OF SIR RUPERT CROSS 172, 172–
92 (Butterworths ed., 1981).
15. See SIMON, supra note 6, at ch. 4.
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there is no reliable evidence that contradicts their statements. This occurs, for
example, when the witness is the sole source of evidence, such as when she was
the victim of a crime committed in private, or when she happened to be the only
person to witness the criminal event. Due to opacity of the investigations, the
limited scope of the prosecution’s duty to disclose exculpating evidence, and the
credibility advantage that police officers enjoy over criminal defendants, police
investigators will usually have little reason to be concerned about being
confronted with contradictory evidence.16 There will be no reliable evidence to
contradict a witness’s statement also when that testimony is corroborated by the
rest of the available evidence, although the apparent corroboration might be a
misleading artifact of the investigative process. Due to the escalating nature of
investigations, the accumulation of evidence tends to be driven by the
previously available evidence.17 Paradoxically, it is possible that the
corroborating evidence itself was induced by an investigation that was thrown
off course by the erroneous testimony now being corroborated.
Witnesses also have little to fear when they know that the jury is strongly
disposed to believe them. This is often the case when the witness is a
sympathetic victim or, in most jurisdictions, when she is a police officer or
public official. Witnesses also have little reason to fear being exposed on the
stand when they expect to be discredited no matter what. This is the case for
witnesses who perceive that the jury is predisposed to disbelieve them, and it is
also generally true for expert witnesses who testify for hire. These experts tend
to adopt the position of the party that hires them, and fully expect to be
hammered by the opposing side.18
The second manner in which cross-examination could improve the
diagnosticity of the trial is by exposing mistakes or lies in the course of the
cross-examination itself. It is beyond dispute that such exposures (call them
Perry Mason moments) enhance the accuracy of the evidence presented to the
jury. Yet these dramatic instances are few and far between. Witnesses are
habitually prepared by lawyers, and this usually means that their testimony has
been massaged to look as reliable as possible. Witnesses are also advised by the
lawyers on what to expect during cross-examination and how best to respond to
The infrequency of the Perry Mason moments also stems from the strategic
risks involved in seeking to expose witnesses on the stand. Attempting, but
failing, to expose a witness as deceitful can be very costly. For one, repeated
questioning of the witness gives her another opportunity to reiterate her
statements. More importantly, weathering a cross-examination can make her
16. On the opacity of investigations, see SIMON, supra note 6, at ch. 6. On the limited prosecutorial
obligations to disclose exculpating evidence to the defense, see id. at ch. 8.
17. See id. at chs. 2, 6.
18. See Ralph Underwager & Hollida Wakefield, Responding to Improper and Abusive
Impeachment Efforts, 14 AM. J. FORENSIC PSYCHOL. 5 (1996).
19. See SIMON, supra note 6, at ch. 6.
testimony seem even more reliable and thus bolster the effectiveness of her
testimony. Hence the famous adage, “[Y]ou should never ask a question to
which you do not already know the answer.”20 The effectiveness of
crossexamination is particularly limited for defense attorneys, who labor under an
informational disadvantage. The vast majority of criminal defendants lack the
resources, expertise, and legal authority to investigate crimes effectively. While
the prosecution has a virtual monopoly on the evidence, its duties to share
exculpating evidence are rather limited.21 Vigorous cross-examination can also
be perceived by the fact finder as unduly hostile and thus off-putting.22 Again,
this concern is particularly constraining for defense attorneys as jurors tend to
react negatively to the badgering of victims,23 bystanders, and police officers.
Moreover, cross-examination can hamper the diagnosticity of the process by
undermining the testimony of even honest and accurate witnesses.24 Indeed,
some commentators argue that assailing the reliability of all opposing witnesses
is a professional duty that a lawyer owes her client in an adversarial system.25 A
recent study shows that subjecting honest witnesses to a realistic
crossexamination results in substantial changes in their testimony with almost
threequarters of witnesses altering their responses on at least one of the four factual
issues that were critical to the outcome of the case.26 One technique for
undercutting a witness is to phrase the questions in convoluted language,
pejoratively dubbed “lawyerese.” These questions can come in the form of
leading questions, questions phrased in the negative or double negative form,
and multipart questions. Studies show that these questions increase the rate of
erroneous and “don’t know” responses.27 Questions phrased in lawyerese have
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also been found to reduce the confidence of witnesses, regardless of their
accuracy,28 thus further weakening the limited diagnostic value of witness’s
Occasionally, the quest to discredit witnesses injects a degree of acrimony
and even viciousness into the proceedings. One manual evokes images of
hunting when advising how to conduct cross-examination: “Close all the gaps he
might try to slither through,” and “pin him down—don’t spring the trap too
soon.”30 The anticipation of being vigorously cross-examined by opposing
counsel tends to entrench witnesses in their position and feel more strongly
aligned with the party for whom they are testifying. Indeed, lawyers often prime
their witnesses for a battle with the opposing attorney. One study showed that
preparing a prosecution eyewitness for a hostile cross examination bolstered the
incriminating strength of that witness’s testimony and resulted in an increased
rate of guilty verdicts.31
Cross-examination can also compromise the process by influencing the
selection of witnesses on grounds other than the accuracy of their testimony.
Lawyers might well elect not to bring to the stand an honest and reliable
witness because she might “not hold up well” to the vigor of cross-examination,
whether due to a personality trait, low intelligence, and the like. By the same
token, a lawyer would be tempted to call a witness who is expected to stand up
to the task, even if she suspects his integrity or the reliability of his account.
Thus, while cross-examination should help deter dishonest witnesses and
expose the truth on the stand, its effectiveness and availability are limited, and
it can even have an adverse effect on the accuracy of the process.
A primary justification cited for entrusting jurors with the task of deciding
criminal verdicts is that they infuse the decisionmaking process with common
sense.32 At the same time, a fundamental tenet in democratic regimes is that the
imposition of guilt must be done in accordance with the formal dictates of the
law.33 The primary means by which the legal process seeks to subordinate jury
verdicts to the appropriate legal rules is by means of a formal set of instructions
28. Jacqueline M. Wheatcroft et al., The Influence of Courtroom Questioning Style on Actual and
Perceived Eyewitness Confidence and Accuracy, 9 LEGAL & CRIMINOLOGICAL PSYCHOL. 83, 83
29. On the accuracy–confidence relationship, see SIMON, supra note 6, at chs. 3, 4.
30. KEITH EVANS, THE COMMON SENSE RULES OF TRIAL ADVOCACY 135–36 (1994).
31. Gary L. Wells et al., The Tractability of Eyewitness Confidence and Its Implications for Triers
of Fact, 66 J. APPLIED PSYCHOL. 688 (1981).
32. As the Supreme Court stated in Taylor v. Louisiana, juries embody “the commonsense
judgment of the community” as a check against prosecutorial excesses and “in preference to the
professional or perhaps over-conditioned or biased response of a judge.” 419 U.S. 522, 530 (1975).
33. The principle nullum crimen sine lege states that conduct does not constitute a crime unless it
has previously been declared to be so by the law.
conveyed to the jury by the trial judge. In addition to the definition of the
criminal charge, jury instructions contain numerous rules designed to delineate
the framework for deciding the verdict, including the primacy of trial evidence,
the presumption of innocence, and the standard of proof. To reach legally
warranted verdicts juries need to apply these rules in the prescribed manner.
Sometimes, juries deliberately disregard the instructions, thus engaging in jury
nullification.34 The following discussion, however, is concerned instead with
unwitting failures in applying instructions.35
Driven by a fidelity to the law and by the fear of being overturned on
appeal, trial judges typically provide jurors with instructions that adhere to legal
rules, even when doing so entails issuing instructions that are beyond the grasp
or capabilities of most people. Jury instructions are often complex, couched in
alien terminology, and demanding of unfamiliar and even improbable mental
exercises. Still, the legal system relies heavily on the assumption that juries
conform to the instructions they receive, and the Supreme Court routinely
proclaims its faith in their conformity. A crucial assumption underlying that
system is that juries will follow the instructions given them by the trial judge.”
To support this belief, the Court has offered the circular argument that if jurors
did not follow instructions, “it would be pointless for a trial court to instruct a
jury, and even more pointless for an appellate court to reverse a criminal
conviction because the jury was improperly instructed.”36 Underlying this faith
is the belief that although jurors are endowed with a keen eye for discerning
human behavior and a developed sense of morality, they are also remarkably
malleable to the dictates of the law, even when it conflicts with their personal
sense of justice. Just how well jurors comprehend and apply jury instructions is
an empirical question. The following discussion tracks the two primary
functions served by jury instructions: guiding jurors toward proper
decisionmaking, and protecting decisions from potential prejudice.
A. Guidance Instructions
One way to gauge the effectiveness of instructions in guiding jury
decisionmaking is to measure how well jurors comprehend them. A sizeable
body of research indicates that jurors’ performance falls well short of law’s
implicit assumption of complete or near-complete comprehension. The studies
find comprehension rates ranging from thirteen to seventy-three percent, levels
that are not always better than chance,37 and are far inferior to the law’s implicit
34. See generally Nancy S. Marder, The Myth of the Nullifying Jury, 93 NW. U. L. REV. 877 (1999);
VIDMAR & HANS, supra note 3.
35. It should be acknowledged that a failure to follow jury instructions means that the verdict is
not likely to comport with the prescribed law, but that does not necessarily compromise the factual
accuracy of the decision. In some instances—such as when the rules of evidence mandate keeping a
piece of accurate evidence out of court—the failure to follow the instruction could actually increase the
accuracy of the verdict.
36. Parker v. Randolph, 442 U.S. 62, 73 (1979).
37. For example, a large post-deliberation study of instruction comprehension found levels of
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assumption of complete or near-complete comprehension. The data are mixed
as to whether the instructions actually improve jurors’ understanding of the law,
with some studies finding modest improvement,38 and others finding that
instructed jurors are no more knowledgeable than their non-instructed
cohorts.39 A study conducted in England found that people tend not to
acknowledge their limited levels of knowledge. While only thirty-one percent of
respondents understood the instructions, two-thirds of them maintained that
they comprehended them correctly. Notably, the level of comprehension
increased to almost one-half when the instructions were given in writing.40 The
comprehension of instructions is particularly low when they pertain to issues
about which jurors hold incorrect preexisting beliefs or which entail unfamiliar
Similar questions arise when lay people are tested on their ability to apply
jury instructions to legal situations. Studies with jurors in Washington state and
Florida found that instructed and uninstructed participants performed similarly
in applying instructions.42 Notably, studies have found that decisions are often
unaffected by the instructions given. In deciding homicide cases, simulated
jurors rendered the same verdicts under two discrepant definitions of the
crime.43 Similar ineffectiveness was found in experiments that compared
discrepant instructions for the crime of rape,44 and for the insanity defense.45
accuracy around 30%. REED HASTIE ET AL., INSIDE THE JURY (1983). Comprehension levels on
insanity defense instructions were found to range from 15% to 43% correct. James R. P. Ogloff, A
Comparison of Insanity Defense Standards on Juror Decision Making, 15 LAW & HUM. BEHAV. 509,
512 (1991). For a review of the research, see generally Joel D. Lieberman, & Bruce D. Sales, What
Social Science Teaches Us About the Jury Instruction Process, 3 PSYCHOL. PUB. POL’Y & L. 589 (1997).
38. See, e.g., Raymond W. Buchanan et al., Legal Communication: An Investigation of Juror
Comprehension of Pattern Instructions, 26 COMM. Q. 31, 34 (1978); David U. Strawn & Raymond W.
Buchanan, Jury Confusion: A Threat to Justice, 59 JUDICATURE 478, 482 (1976).
39. For example, a study of Michigan jurors found that instruction increased correct responses on
procedural rules, but not on definitions of crimes. In this study, the level of comprehension was shy of
fifty percent on both types of instructions. Alan Reifman et al., Real Jurors’ Understanding of the Law
in Real Cases, 16 LAW & HUM. BEHAV. 539, 547 (1992).
40. Cheryl Thomas, Are Juries Fair?, MINISTRY OF JUSTICE RESEARCH SERIES, vi (Feb. 2010),
41. For example, Michigan jurors’ responses barely reached chance level on instructions
pertaining to the use of evidence for limited purposes and the definition of specific intent. Geoffrey P.
Kramer & Dorean M. Koenig, Do Jurors Understand Criminal Jury Instructions? Analyzing the Results
of the Michigan Juror Comprehension Project, 23 U. MICH. J. L. REFORM 401, 417 (1990).
42. In the Washington sample, instructed participants applied the instructions correctly sixty
percent of the time. Laurence J. Severance & Elizabeth F. Loftus, Improving the Ability of Jurors to
Comprehend and Apply Criminal Jury Instructions, 17 LAW & SOC’Y REV. 153, 181 (1982); Buchanan
et al., supra note 38.
43. Nonetheless, respondents relied on the wording of the definitions to justify their decisions.
Matthew P. Spackman et al., An Analysis of the Effects of Subjective and Objective Instruction Forms on
Mock-Juries’ Murder/Manslaughter Distinctions, 26 LAW & HUM. BEHAV. 605, 612–14 (2002).
44. A study by Dan Kahan found no difference in conviction rates among three different crime
definitions (ranging from 53% to 55%). Minor differences were observed with two unconventional
instructions (rates of 62% and 65%). Dan M. Kahan, Culture, Cognition, and Consent: Who Perceives
What, and Why, in Acquaintance-Rape Cases, 158 U. PA. L. REV. 729, 773–83 (2010).
Perhaps the strongest impediment to the instruction of juries is the jurors’
own preconceptions of law and justice.46 People’s decisions tend to conform
more to their personal preconceptions than to the instructions they receive.
Even after receiving instructions on the definitions of crimes such as robbery,
burglary, and kidnapping, lay people continued to apply their preexisting, and
often mistaken, understandings of these offenses.47 When explicitly instructed to
use a standard of proof threshold of ninety percent, simulated jurors reported
using an average standard of eighty-five percent, which appears to have been a
compromise between the instructed threshold and the one they reported absent
an instruction (seventy-eight percent).48 Notably, judges too seem to subject
their compliance with legal rules to their personal sense of justice.49
B. Curative Instructions
Another type of jury instructions is designed to “cure” the process of
potential biases. Oftentimes, curative instructions are administered to remedy
the exposure of jurors to potent information that is not admissible as evidence.
Such exposure can originate outside the courtroom, typically in the form of
pretrial publicity, or it can derive from statements uttered by the lawyers inside
the courtroom, whether unwittingly or deliberately. At times, counsel will
request the judge to call a mistrial, but such motions rarely succeed. More
frequently, the judge will either deny the motion outright or issue an instruction
admonishing the jury to ignore the information.
A number of psychological reasons warrant suspicion about the curative
potential of judicial admonitions. Research on “ironic mental processes” has
shown that instructing people to suppress a thought is a difficult mental feat,
which can even backfire by increasing the salience of the thought.50 Indeed, in
some jury simulations, issuing instructions to ignore evidence actually increased
the impact of the impermissible evidence on the decision.51 Likewise, research
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on “reactance theory” suggests that people respond negatively to restrictions on
their freedom. One reactive response is to increase the value of the deprived
freedom, which could amount to placing greater emphasis on the information
that is supposed to be ignored.52 Research on “hindsight bias” indicates that
people have a difficult time imagining their state of knowledge in the absence of
information they already have.53 Research on “belief perseverance” indicates
that people tend to adhere to beliefs that they have form, even after learning
that the information they used to form those beliefs has been discredited.54
The research findings on the effectiveness of curative instructions are
somewhat muddled.55 Some clarity can be attained, first, by appreciating the
role of people’s personal conceptions of justice, which pertain both to their
individual policy preferences as well as to the perceived probativeness and
reliability of the information. For example, instructions to ignore information
were found to be effective when it was unreliable, such as when the wiretapped
confession was barely audible,56 or when the source of the information
originated from a non–credible source.57 Conversely, admonitions failed to
defuse information that was considered to be probative of the defendant’s
guilt.58 Admonitions were also ineffective when the grounds for their exclusion
could be considered “legal technicalities,” such as when the incriminating
conversation was obtained by means of illegal wiretap,59 or when the murder
weapon was obtained in an illegal search.60
In short, people appear to follow instructions that are consistent with their
intuitions and inclinations, but disregard instructions that run contrary to
them.61 It is notable that judges behave in a similar manner. A study of sitting
judges found that they cannot refrain from being swayed by probative
information that they themselves ruled inadmissible.62
A second way to clarify the research on curative instructions is to distinguish
between instructions to disregard evidence completely and instructions to admit
evidence for limited purposes. “Limited purpose” instructions are borne by the
need to reconcile conflicting policy considerations. When it comes to admitting
the defendant’s prior criminal record, for example, the rules of evidence split
the difference by positing that evidence of prior convictions cannot be admitted
to support inferences about the defendant’s propensity to commit the crime, but
it can be admitted to prove other aspects of the charge or to impeach the
credibility of the testifying defendant.63 To address this palpable contradiction,
the rules advise judges to “restrict the evidence to its proper scope and instruct
the jury accordingly.”64 Limited purpose instructions are premised on a belief in
people’s ability to exert formidable control over their cognitive processing. This
assumption runs contrary to the research. Many social judgments occur
automatically,65 and thus resist conscious control.66 Given that turning
information one and off at will is an unnatural task that is unparalleled in
everyday life, it is not surprising to find that this instruction is basically
ineffective in preventing the drawing of impermissible conclusions. A number
of jury simulation studies find that despite limiting instructions, exposing jurors
to the defendant’s prior criminal record results in higher conviction rates.67 A
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meta-analysis shows that evidence of prior criminal behavior is generally
resistant to curative instructions.68 Paradoxically, the instruction limiting the use
of prior criminal behavior bears only mixed and weak results with respect to its
ostensibly justified objective, namely, impairing the credibility of the
defendants’ testimony.69 Limiting instructions were also found to be ineffective
when used to neutralize the effects of evidence of bad character,70 and of joining
multiple crimes into a single trial.71
Courts have long been skeptical about of the effectiveness of curative
instructions. Justice Robert Jackson described them as an “unmitigated
fiction,”72 and Judge Learned Hand characterized them as a “mental gymnastic”
that is beyond the jury’s powers.73 Judge Jerome Frank described them as “a
kind of ‘judicial lie’” that “damages the decent judicial administration of
justice.”74 Ignoring inadmissible evidence has also been likened to “unringing
the bell,”75 and “ignoring the smell of a skunk just thrown into the jury box.”76
For the most part, however, this skepticism has rarely been acknowledged by
the Supreme Court in recent years. Under the stewardship of Chief Justices
Burger, Rehnquist, and Roberts, the Court has shown no hesitation in asserting
that juries can and will disregard inadmissible evidence when instructed to do
The practical implications of exposure to inadmissible evidence go beyond
the limited effectiveness of curative instructions. The research shows that the
judge’s decision to admit the contested evidence can actually backfire by
boosting its impact on the verdict.78 This prospect of an adverse effect poses a
serious dilemma for the attorneys. Refraining from objecting to prejudicial
evidence runs the risk of leaving the jury exposed to that prejudicial
information. Yet objecting to the evidence will, at best, result in a relatively
ineffective curative instruction and, at worst, will actually bolster the prejudicial
effect. This perilous situation is often a double blow for the defendant in that
the prejudicial fact—particularly a defendant’s prior record—has possibly
already contributed to the police’s decision to investigate him in the first place
and the prosecutor’s decision to follow through with the charges.
C. Capital Sentencing
Nowhere do jury instructions play as critical a role in legal decisionmaking
as in the context of capital sentencing, and nowhere are the misconceptions of
jurors’ performance as consequential.79 Since the 1970s, the primary focus of the
debate over the death penalty has not been the constitutionality of execution
per se, but the fairness of its administration. The current state of the law was
forged by two landmark decisions of the Supreme Court. In Furman v. Georgia,
the majority of the justices decried the extant unbridled jury discretion,
determining it to constitute cruel and unusual punishment, and thus violative of
the Eighth Amendment.80 Four years later, in Gregg v. Georgia, the Court
reinstated the practice by endorsing Georgia’s regime of “guided discretion,” a
sentencing framework that sought to rein in the jury’s discretion while
maintaining enough latitude for individualized justice.81 The Court heralded the
proposed regime, characterizing it as a “carefully drafted statute that ensures
that the sentencing authority is given adequate information and guidance.”82
While the specific instantiations of the guided discretion regime vary
somewhat over time and across jurisdictions, they share three key features.
First, the jury must find at least one of the enumerated “aggravating factors”
that increase the blame of the defendant (for example, murdering a police
officer or killing multiple victims). Typically, the finding of aggravating factors
79. The following discussion does not purport to cover the vast range of psychological issues
involved in the topic of capital punishment. It is confined to jurors’ ability to comprehend and follow
the sentencing instructions.
80. This ruling struck down all extant capital sentencing statutes and vacated the death sentences
of some six hundred people then inhabiting death row. Justice Stewart’s plurality opinion found that, in
practice, death sentencing was performed “wantonly and freakishly” befalling only the “capriciously
selected random handful.” Receiving the punishment was not unlike “being struck by lightning.”
Furman v. Georgia, 408 U.S. 238, 309–10 (1972). Justice Brennan likened the arbitrariness to a “lottery
system.” Id. at 293. While most of the justices shunned the thorny issue of race, racial disparities were
clearly on the justices’ mind. Justice Douglas highlighted the death penalty’s discriminative effect on
black people, the poor, and the uneducated. For example, Douglas’s opinion included data showing a
disparity in the rate of commutations of death sentences (20% for whites and 12% for blacks). Id. at
250. The discriminatory effects of the punishment were quite obvious. For example, in the forty years
preceding the case, 405 black men had been executed for the crime of rape, whereas only 45 white
people were executed for the same crime. CRAIG HANEY, DEATH BY DESIGN: CAPITAL PUNISHMENT
AS A SOCIAL PSYCHOLOGICAL SYSTEM 14 (Ronald Roesch ed., 2005).
81. Gregg v. Georgia, 428 U.S. 153, 195 (1976). On the political environment that spurred the
reinstatement of the death penalty statutes, see STUART BANNER, THE DEATH PENALTY: AN
AMERICAN HISTORY (2002).
82. Gregg, 428 U.S. at 195.
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must be made unanimously, and be determined beyond a reasonable doubt.
Yet, even if aggravating factors are found, the death sentence is not automatic.
The jurors must also consider factors that bode for sparing the defendant’s life.83
These “mitigating factors” can be established by the relatively low threshold of
preponderance of the evidence (or no threshold at all), and do not require the
unanimous agreement of all jurors. Mitigating factors need not be enumerated
in the statute, but can encompass any fact that tends to lessen the defendant’s
blame. Finally, jurors are given a “decision rule” that prescribes how to weigh
the aggravating factors against the mitigating factors in making the choice
between a death sentence and the alternative punishment, which is typically life
imprisonment without the possibility of parole.
The legality and legitimacy of the death penalty regime rely heavily on
jurors’ ability to abide by the procedure of guided discretion. Given that jurors
find it difficult to comprehend and apply relatively straightforward instructions
in non-capital procedures, it should come as no surprise to find that they fall
short in mastering the intricate and unfamiliar mental procedure prescribed by
the guided discretion regime. A series of studies by Craig Haney and Mona
Lynch tested jury eligible Californians for their comprehension of the state’s
death sentencing instructions. Even after hearing the instructions three times,
jury eligible respondents were largely unsuccessful in defining the terms
“aggravating” and “mitigating.” Fewer than half of the participants provided
accurate definitions for both terms aggravation and mitigation, and only eight
percent provided definitions that were legally correct.84 Of particular interest
are the misunderstandings of mitigation, which typically offers defendants the
only chance of coming out of the process alive. About one-quarter of the
respondents mistook two of the mitigating factors to be aggravating factors, and
more than one-third misinterpreted the most important mitigating factor—“any
other circumstances that extenuate the gravity of the crime”—as grounds to
buttress a death verdict.85 Respondents also manifested low comprehension of
the all-important decision rule. Only one-half stated (correctly) that a death
verdict was impermissible when the mitigating factors outweighed the
aggravating factors, and only fifteen percent said the same (correctly) when the
83. Lockett v. Ohio, 438 U.S. 586, 601 (1978). More recently, the Court has stated that jurors
ought to be given the opportunity “to give meaningful consideration and effect to all mitigating
evidence that might provide a basis for refusing to impose the death penalty.” Abdul-Kabir v.
Quarterman, 550 U.S. 233, 234 (2007).
84. Correct or partially correct definitions were given for the term “aggravating” by 79% of the
respondents, but only by 59% for the term “mitigating.” Craig Haney & Mona Lynch, Comprehending
Life and Death Matters: A Preliminary Study of California’s Capital Penalty Instructions, 18 LAW &
HUM. BEHAV. 411, 421 (1994) [hereinafter Haney & Lynch, Comprehending Life and Death Matters].
See also Craig Haney & Mona Lynch, Clarifying Life and Death Matters: An Analysis of Instructional
Comprehension and Penalty Phase Closing Arguments, 21 LAW & HUM. BEHAV. 575, 579–80 (1997)
[hereinafter Haney & Lynch, Clarifying Life and Death Matters].
85. The likely reason for the difficulty in comprehending the catch-all mitigator is the relative
unfamiliarity of the word “extenuate.” Haney & Lynch, Comprehending Life and Death Matters, supra
LAW AND CONTEMPORARY PROBLEMS
factors were balanced equally. Forty percent stated (incorrectly) that death was
mandatory when the aggravating factors outweighed the mitigating ones.86 A
follow up study by Haney has found that comprehension improves somewhat
thanks to the psycholinguistically improved instructions that were put into
effect in California in 2006,87 and it can be improved even more by using
instructions that provide jurors with thematic and case specific examples
presented in a relevant and concrete manner. Still, even with these modified
instructions, the level of comprehension remains rather low.88
Another series of studies was conducted by Richard Wiener and his
colleagues, testing juror comprehension of the Missouri death penalty
instructions. These studies found overall comprehension levels of between
fiftyfive and sixty percent, which is just slightly better than guessing.89 Particularly
poor levels were observed with respect to some of the procedure’s central
features, including the need for unanimity in finding aggravating factors, the
freedom to consider mitigating factors that are not enumerated in the statue,
and the decision rule for weighing the countervailing factors.90 Substandard
comprehension was also observed in studies testing the instructions used in
Illinois,91 Florida,92 Ohio,93 and Tennessee.94
Given that the guided discretion regime works primarily to inhibit jurors’
discretion to award death sentences, poor comprehension is prone to
undermine the protections promised by this procedure. The misconceptions
observed in the studies—notably, relaxing the limits on finding aggravating
factors, narrowing the scope for establishing mitigating factors, and
underappreciating the freedom to vote for imprisonment even in the face of
aggravating factors—all result in higher rates of death sentences than intended
by the law. Indeed, studies find a consistent relationship between
comprehension and death sentencing; the less jurors understand the
instructions, the more prone they are to vote for death.95 Relatedly,
comprehension is inversely correlated with jurors’ support for the death
penalty, in that those who strongly support the practice tend to display poorer
comprehension.96 Thus, the procedure of death qualification—which excuses
jurors who express a strong aversion to voting for a death sentence—decreases
the jury’s overall level of comprehension, and thus further increases the
likelihood of a death sentence.97 Instruction comprehension also interacts with
racial bias. Low comprehension has been found to be related to a greater
tendency to sentence black defendants to death, particularly when their victims
The findings from the laboratory and field studies are notably consistent
with data from the Capital Juror Project, which has conducted in-depth
interviews with some 1,200 jurors who served on 350 capital sentencing cases in
14 states. One of these studies found that almost half of the jurors
fundamentally misunderstood the concept of mitigation, believing that under
certain circumstances death was “the only acceptable punishment.” Not
surprisingly, jurors who failed to appreciate their duty to explore mitigating
factors were five times more likely to decide prematurely on a death sentence
than those who understood the instruction correctly. The influence of jurors’
preconceived notions of justice was manifested by a greater endorsement of
mandatory death (which is always incorrect) for more reprehensible murder
charges.99 A significant number of South Carolina jurors mistakenly stated that
95. Diamond & Levi, supra note 91, at 231; Wiener et al., supra note 90, at 463; Wiener et al.,
supra note 89, at 138.
96. Mona Lynch & Craig Haney, Capital Jury Deliberation: Effects on Death Sentencing,
Comprehension, and Discrimination, 33 LAW & HUM. BEHAV. 481, 489 (2009); Mona Lynch & Craig
Haney, Discrimination and Instructional Comprehension: Guided Discretion, Racial Bias, and the Death
Penalty, 24 LAW & HUM. BEHAV. 337, 347 (2000) [hereinafter Lynch & Haney, Discrimination and
Instructional Comprehension] .
97. The more serious problem caused by the policy of death qualification is that it precludes
people who tend to be more lenient from sitting on juries. The research shows that the preclusion of
these venire members increases the likelihood that the defendants will be convicted in the first place.
See Brooke M. Butler & Gary Moran, The Role of Death Qualification in Venirepersons’ Evaluations of
Aggravating and Mitigating Circumstances in Capital Trials, 26 LAW & HUM. BEHAV. 175, 183 (2002);
Kevin O’Neil et al., Exploring the Effects of Attitudes Toward the Death Penalty on Capital Sentencing
Verdicts, 10 PSYCHOL., PUB. POL’Y & L. 443, 463–66 (2004).
98. Of the jurors whose comprehension was in the lower half, 60% voted for the death sentence
when the defendant was black, whereas only 41% voted the same when he was white. The disparity was
even greater between black defendants charged with killing white victims (68%) and white defendants
charged with killing black victims (36%). Lynch & Haney, Discrimination and Instructional
Comprehension, supra note 96, at 350.
99. While some seventy percent of the respondents believed that death was mandatory for repeat
murderers, only about one quarter shared the same position for murders that are generally perceived to
be less condemnable. William J. Bowers et al., The Capital Sentencing Decision: Guided Discretion,
LAW AND CONTEMPORARY PROBLEMS [Vol. 75:167
the law prescribed certain aggravating factors that were intuitively plausible,
but that were not mentioned in the instructions.100
The most telling evidence of the shortcomings of the guided discretion
regime comes from naturalistic sentencing data. A large body of econometric
research shows that death sentencing in the post-Gregg regime continues to be
performed in an unprincipled manner. The landmark study was conducted by
David Baldus and his colleagues on death sentencing in the state of Georgia,
where the cases of Furman and Gregg originated. This study, which examined
the 2,484 homicide cases decided between 1973 and 1979, concentrated on racial
discrimination, the most salient impermissible influencing factor. The study
found that jury-sentencing decisions were affected by the races of the
defendants and their victims. White defendants were sentenced to death at a
rate of 8% for killing white victims but only 3% for killing black victims. In
contrast, 22% of black defendants were sentenced to death for killing white
victims, but only 1% received death sentences for killing black victims.101 The
findings of this study were presented to the Court in McCleskey v. Kemp, but
they failed to rattle the justices’ trust in the restraining power of the guided
discretion doctrine.102 Racial discrimination in meting out the death penalty has
been observed in a number of other jurisdictions, including Northern states,103
Reasoned Moral Judgment, or Legal Fiction, in AMERICA’S EXPERIMENT WITH CAPITAL
PUNISHMENT: REFLECTIONS ON THE PAST, PRESENT, AND FUTURE OF THE ULTIMATE PENAL
SANCTION 413 (James R. Acker et al., eds., 2d ed. 2003).
100. Some thirty percent of jurors who sat on South Carolina death penalty cases stated that the
law requires imposition of a death sentence where the jury finds that the defendant will be dangerous in
the future. This erroneous belief is patently driven by people’s preconceptions, because future
dangerousness is not even mentioned in the jury instructions. Theodore Eisenberg & Martin T. Wells,
Deadly Confusion: Juror Instructions in Capital Cases, 79 CORNELL L. REV. 1, 6 (1993).
101. The study also found strong disparities in the exercise of prosecutorial discretion, as the death
penalty was sought in 19% of the cases in which a white man was charged with killing a black man, but
in 70% of the cases where the races were reversed. A regression analysis showed that killing a white
victim had roughly the same impact on the likelihood of receiving a death sentence as did aggravating
factors that were officially prescribed, such as the defendant’s serious prior criminal record or the fact
that the death was perpetrated for the purpose of an armed robbery. Killing a white defendant had
three times the impact as killing a police officer. DAVID C. BALDUS ET AL., EQUAL JUSTICE AND THE
DEATH PENALTY: A LEGAL AND EMPIRICAL ANALYSIS 327 (1990). See also David C. Baldus et al.,
Comparative Review of Death Sentences: An Empirical Study of the Georgia Experience, 74 J. CRIM. L.
& CRIMINOLOGY 661 (1983); David C. Baldus et al., Race Discrimination and the Death Penalty in the
Post-Furman Era: An Empirical and Legal Analysis with Recent Findings from Philadelphia, 83
CORNELL L. REV. 1638, 1694 (1998); John Blume et al., Explaining Death Row’s Population and Racial
Composition, 1 J. EMPIRICAL LEGAL STUD. 165, 204 (2004).
102. The Court simply asserted that the jury’s discretion is “controlled by clear and objective
standards so as to produce non-discriminatory application.” McCleskey v. Kemp, 481 U.S. 279, 302
103. A study of capital sentencing in Philadelphia revealed that juries were twice as likely to
sentence a black defendant to death as a non-black defendant (24% versus 12%). This study contained
338 sentencing decisions rendered between 1978 and 2000. David C. Baldus & George Woodworth,
Race Discrimination in the Administration of the Death Penalty: An Overview of the Empirical Evidence
with Special Emphasis on the Post-1990 Research, 39 CRIM. L. BULL. 194, 206 (2003). In Maryland,
juries sentenced to death almost half of the black defendants convicted of killing white victims but only
one-third of white defendants convicted of killing black victims. Overall, taking the entire process into
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LIMITED EFFECTIVENESS OF LEGAL MECHANISMS 185
and has been confirmed by the U.S. General Accounting Office.104 In sum, it
appears that the touted regime of guided discretion provides little guidance, yet
allows much discretion. Death penalty sentences continue to be meted in the
prejudicial manner found to be unconstitutional in Furman v. Georgia.
JURORS’ ASSURANCE OF IMPARTIALITY
It is well established that people’s decisions are affected by their attitudes,
preferences, beliefs, moral convictions, and the like. The legal system is
cognizant and accepting of these effects on juror decisionmaking, and it would
be quite impossible and indeed unwise to try to rid jurors of them. At the same
time, there are good reasons to curb the excesses of idiosyncratic influences,
since the integrity of the criminal justice process is compromised when the
jurors’ decision in a given case is overpowered by their prior positions. Hence
the Sixth Amendment’s guarantee of the right to an impartial jury. Weeding out
partial jurors is the primary ostensible objective of the jury selection
procedure.105 A key factor in deciding whether to place a veneer person on the
jury is her assurance to the court that she can be unbiased. Assurances of
impartiality are used similarly during the trial to allay any suspicion of
contamination, such as following exposure to inadmissible information.
The shared wisdom within the legal system is that jurors are quite capable of
assessing their objectivity. While the Supreme Court acknowledges the
difficulty in knowing “the imponderables which cause one to think what he
thinks,” it insists that jurors can rise to the occasion: “[S]urely one who is trying
as an honest man to live up to the sanctity of his oath is well qualified to say
whether he has an unbiased mind in a certain matter.”106 Whether jurors can
reliably vouch for their own impartiality is an empirical question.
To meet this expectation, jurors would need, first, to be sufficiently
introspective so as to be able to identify which factors actually influence their
consideration, black defendants charged with killing white victims are 4.1 times more likely to receive a
death sentence than when the races are reversed. Raymond Paternoster et al., Justice By Geography
and Race: The Administration of the Death Penalty in Maryland, 1978–1999, 4 MD. L.J. RACE,
RELIGION, GENDER 1, 39 (2004). In New Jersey, the rate of death sentences awarded to killers of white
victims was 1.7 times higher than for killers of black victims. Among all death eligible cases, 12% of
cases resulted in death sentences for killing white victims, but only 7% for killing black victims. DAVID
S. BAIME, REPORT TO THE NEW JERSEY SUPREME COURT: SYSTEMIC PROPORTIONALITY REVIEW
PROJECT 2004–2005 TERM 6, 17–18 (2005), http://www.judiciary.state.nj.us/pressrel/
104. This review concluded that even after controlling for all legally relevant variables, differences
remain in the likelihood of receiving the death penalty based on race of victim. U.S. GOV’T
ACCOUNTABILITY OFFICE, GAO/GGD–90–57, DEATH PENALTY SENTENCING: RESEARCH
INDICATES PATTERN OF RACIAL DISPARITIES (1990). For a summary of findings from seventeen
states and the federal system, see generally Baldus & Woodworth, supra note 103.
105. As some critics charge, the litigants’ true objective in jury selection is not to attain a fair
representation of the community or to maximize the chances for a fair trial in other ways. Rather, they
use the process to stack the jury box with people whom they expect will vote in their favor.
106. Smith v. Phillips, 455 U.S. 209, 217 (1982).
decisions. Psychological research has long distinguished between access to
“declarative” and “procedural” types of knowledge. People have generally
reliable access to the former, which enables fairly accurate reporting of the
contents of one’s thoughts, such as one’s beliefs, decisions, and emotional states.
At the same time, the cognitive mechanisms and processes used to arrive at
those mental states are generally inaccessible to introspection.107 Notably,
people have only limited access to the situational factors that actually influence
their decisions108 and behaviors.109 Still, people habitually insist on their
introspective abilities,110 and when asked about the reasons for their decisions
and behaviors, they readily provide spurious explanations: a phenomenon
known as “telling-more-than-you-can-know.”111
The limitations on introspection are even more pronounced when it comes
to the acknowledgment of bias. In a culture that places a premium on
rationality, dependability and predictability, the notion of bias carries a
pejorative connotation. The ubiquitous motive of maintaining a positive
selfconception and public image thus hinders any inclination to concede being
biased. Notably, people tend to believe that they are fair and objective.112 While
people might be open to admitting in general terms that their judgment can be
subject to occasional bias, they rarely concede bias in their current judgments,
107. A sizable body of research shows that much of our reasoning and decisionmaking processes
are conducted without awareness. See generally John A. Bargh & Ezequiel Morsella, The Unconscious
Mind, 3 PERSP. ON PSYCHOL. SCI. 73 (2008). Studies show, for example, that participants are often
unaware of changes in their attitudes that were precipitated by the experiment. Daryl J. Bem & H.
Keith McConnell, Testing the Self-Perception Explanation of Dissonance Phenomena: On the Salience
of Premanipulation Attitudes, 14 J. PERSONALITY & SOC. PSYCHOL. 23, 29 (1970); George R. Goethals
& Richard F. Reckman, The Perception of Consistency in Attitudes, 9 J. EXPERIMENTAL SOC.
PSYCHOL. 491, 498 (1973). For findings of unawareness of belief changes, see generally Keith Holyoak
& Dan Simon, Bidirectional Reasoning in Decision Making by Constraint Satisfaction, 128 J.
EXPERIMENTAL PSYCHOL.: GEN. 3 (1999) (studies 2, 3).
108. Richard E. Nisbett & Timothy D. Wilson, Telling More Than We Can Know: Verbal Reports
on Mental Processes, 84 PSYCHOL. REV. 231, 233 (1977). Studies of decisionmaking find that
participants’ reports of the weights they assign to decision factors are often substantially discrepant
from the weights objectively derived from their decisions. Paul Slovic & Sarah Lichtenstein,
Comparison of Bayesian and Regression Approaches to the Study of Information Processing in
Judgment, 649 ORGANIZATIONAL BEHAV. & HUM. PERFORMANCE 649, 715–16 (1971).
109. See, e.g., BIBB LATANE & JOHN M. DARLEY, THE UNRESPONSIVE BYSTANDER: WHY
DOESN’T HE HELP? (1970).
110. The belief in one’s introspective abilities has been labeled the “introspection illusion.” Emily
Pronin et al., Objectivity in the Eye of the Beholder: Divergent Perceptions of Bias in Self Versus Others,
111 PSYCHOL. REV. 781, 784 (2004).
111. Nisbett & Wilson, supra note 108, at 255.
112. For people’s beliefs in their fairness, see generally Wim B. Liebrand et al., Why We Are Fairer
Than Others: A Cross-Cultural Replication and Extension, 22 J. EXPERIMENTAL SOC. PSYCHOL. 590
(1986). The beliefs in one’s objectivity is captured by a sense of “naïve realism,” which refers to the
“unshakable conviction that he or she is somehow privy to an invariant, knowable, objective reality—a
reality that others will also perceive faithfully, provided that they are reasonable and rational, a reality
that others are apt to misperceive only to the extent that they (in contrast to oneself) view the world
through a prism of self-interest, ideological bias, or personal perversity.” Robert J. Robinson et al.,
Actual Versus Assumed Differences in Construal: “Naive realism” in Intergroup Perception and Conflict,
68 J. PERSONALITY & SOC. PSYCHOL. 404, 405 (1995).
heightened demands on the prosecution, namely the “presumption of
innocence” and the standard of proof “beyond a reasonable doubt.” The
asymmetry underlying these two measures stems to a large extent from the legal
system’s avowed discrepant aversion to false convictions and false acquittals. As
stated by the Supreme Court, “[I]t is far worse to convict an innocent man than
to let a guilty man go free.”120 This disparity was famously quantified by
Blackstone’s assertion that “the law holds that it is better that ten guilty persons
escape than that one innocent suffer.”121 These measures are generally extolled
in the legal discourse, yet their exact meaning and practical effects are far from
A. The Presumption of Innocence
One possible conception of the presumption of innocence is that it is
directed at law enforcement agencies and courts as an overarching principle to
govern their affairs throughout the criminal justice process. According to this
formulation, any ambiguity should be resolved with an eye toward favoring the
defendant. The Supreme Court, however, has rejected this interpretation. The
Court insists that the presumption is directed only at the fact finder at the trial
phase as an aid in the process of deciding verdicts.122
One way in which the presumption of innocence could aid the
decisionmaking task is to counter the possible suspicion that arises from the fact
that the defendant is the subject of a criminal prosecution.123 Even prior to the
presentation of the prosecution’s evidence, it would be rational for a fact finder
to regard the accused as the likely perpetrator of the crime: Why else would she
be brought to trial? According to one survey, lay people estimate the initial
probability of the defendant’s guilt at close to fifty percent.124 Although this
estimate seems intuitively sensible, it is considerably higher than a presumption
of innocence would imply. Whether the judicial instruction is potent enough to
counter this suspicion and anchor it at a level that befits the criminal system’s
precepts is an empirical question. The scarce available data leave this issue
unsolved. For one, it is unclear whether jurors comprehend this instruction
correctly. In a field study of Wyoming jurors who had received jury instructions,
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LIMITED EFFECTIVENESS OF LEGAL MECHANISMS
forty percent indicated that the charges brought against the defendant were
evidence of his guilt.125 One laboratory simulation demonstrated that the
presumption did have a constraining effect,126 while another study revealed that
simulated jurors assigned low initial probabilities of guilt at first, but abandoned
them once the prosecution evidence starts to come in.127
The presumption of innocence could also aid the decisionmaking task by
instantiating the prosecution’s burden of production, that is, the rule that places
the onus of producing the evidence on the shoulder of the prosecution, and
relieves the defendant from having to prove her innocence. The research shows
that jurors do not always comprehend the asymmetric allocation of the burden,
a concept that has few parallels in everyday life. After being given Florida’s
pattern jury instructions, only half of the jurors surveyed in a Florida
courthouse maintained that the defendant need not present any evidence to
prove his innocence,128 and only three in ten of another group of Florida jurors
correctly understood the prosecution’s burden.129 A failure to understand the
allocation of the burden was also displayed by one-fifth of Wyoming jurors,130
and two-thirds of a sample of Michigan jurors.131
Finally, the presumption of innocence can be conceived as serving the role
of tiebreaker, positing that if the evidence against the defendant does not meet
the requisite standard of proof, she should be acquitted. Here, too, there is
reason for concern. Almost one-quarter of instructed Florida jurors believed
that when faced with two equally reasonable sets of evidence, the defendant
should be convicted.132
B. The Standard of Proof: Beyond a Reasonable Doubt
The criminal process’s signature standard of proof—beyond a reasonable
doubt—has received a fair amount of scholarly attention over the years, yet it
remains elusive and deeply disputed.133 For one, there is considerable
LAW AND CONTEMPORARY PROBLEMS
disagreement as to whether the standard should pertain to the fact finder’s
subjective state of mind, or to a property of the evidence itself. While most
commentators agree with the former formulation,134 there is disagreement as to
whether the standard posits a numeric criterion for assessing the probability of
guilt, or whether it prescribes a threshold for gauging one’s belief in the
inculpatory power of the evidence.135 The latter option, which figures more
prominently in courtroom practice and legal literature,136 is essentially a
metacognitive judgment, not unlike a measure of confidence. There is also
disagreement about the appropriate meaning of the reasonableness criterion,
namely, whether it pertains to the strength of the doubt or to a substantive
judgment of its underlying rationality.137 Another controversy revolves around
the appropriateness of providing jurors with definitions and explanations of the
standard. While some commentators and courts propose that the standard
should be communicated to the jury without attempting to explain it,138 others
insist on supplementing the definition with explanatory language. Among the
latter, some would focus on the doubt itself, for example, “not a possible doubt,
a speculative, imaginary or forced doubt,”,139 whereas most instructions speak of
an absence of such a doubt140 as in “firmly convinced,”141 “an abiding
conviction,”142 “settled belief,” and “near certitude.”143 In practice, many
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LIMITED EFFECTIVENESS OF LEGAL MECHANISMS 191
jurisdictions mix numerous definitions and explanations, thus making for
unwieldy instructions. For example, a Louisiana death sentence was based on a
jury instruction that defined the standard in no fewer than eight ways.144
The available research on the standard of proof leaves much unresolved. A
number of surveys have sought to gauge its effect by asking people to express
their conception of the standard in terms of a probabilistic assessment of their
threshold. The mean responses in most studies hover around 85%,145 which is a
little lower than the value of 90% or higher that is commonly assumed in legal
discourse.146 Although the standard is conceived as invariant to the specifics of
the case, varying the case characteristics in the same study has resulted in
thresholds ranging from 79% to 94%.147 Most notably, there is considerable
variation in assessments of standard. One large sample of respondents reported
an average of 64%,148 whereas large numbers of respondents insist on complete
certainty. Thresholds of 100% were reported by almost 70% of a sample of
Michigan jurors,149 and by more than half of the 500 jury eligible respondents in
a Canadian study.150 A large survey conducted in the United Kingdom obtained
thresholds of 100% certainty from no fewer than one-half of the jurors and
almost one-third of the legal professionals and magistrates surveyed.151
Naturally, requiring absolute certainty should make convictions virtually
impossible; this is clearly contradicted by experimental and naturalistic data.
These high standards are also out of whack with lay people’s intuitions
LAW AND CONTEMPORARY PROBLEMS [Vol. 75:167
regarding the appropriate ratio of false convictions to false acquittals.152
The limited experimental research testing the effect of the standard of proof
on verdict decisions yields mixed results, but it appears that the standard does
indeed exert its intended effect, even if only roughly and partly. Some studies
have found that instructing jurors with the beyond a reasonable doubt standard
reduced conviction rates relative to the “preponderance of the evidence”
standard (as it should).153 Another experiment found that the standard alone has
no appreciable effect, but it reduces conviction rates when combined with the
presumption of innocence instruction.154 However, a field study of more than
300 actual trials conducted by the National Center for State Courts (NCSC)
gives reason for pause. This study, observed the relationship between the
strength of the evidence and the verdicts in each case. As would be expected,
the juries voted to convict at high rates when the strength of the evidence was
described as strong. However, more than half of the jurors voted to convict the
defendant when they felt that the prosecution’s evidence was of medium
strength, and, surprisingly, one in five juries voted to convict even when they
felt that the evidence was weak. A similar pattern of judgments was obtained
from the judges who sat on these cases.155
152. While legal observers tend to follow the classic error ratio of 10:1 proposed by Blackstone, lay
people appear to be far less sensitive to false convictions. Only 66% of respondents indicated that a
false conviction is worse than a false acquittal, with 30% of the respondents maintaining the opposite.
Insa Bechert& Markus Quandt, ISSP Data Report: Attitudes Toward the Role of Government, SOCIAL
SCIENCE OPEN REPOSITORY,
http://www.ssoar.info/ssoar/files/2011/1535/gs%206%20%20issp%20data%20report.pdf. In the Jurors’ Beliefs Survey respondents were provided with a
continuous scale that listed different ratios of false convictions to false acquittals and asked to indicate
their preferred error ratio. The mode response was 1:1, that is, that the errors are equally bad. The
median response was: “It is better to acquit one guilty person than convict one innocent person.” Simon
et al., supra note 145.
The high thresholds provide another reason to doubt that jurors rely on probabilistic
assessments in deciding cases. If jurors reach verdicts based on their strength of belief in the evidence,
the unrealistic numeric thresholds they report would not necessarily impede on their performance.
153. In one study, the heightened standard reduced the rate of convictions by deliberating
participants from 42% to 26%, which was marginally significant. No difference was observed for
nondeliberating jurors. Robert J. MacCoun & Norbert L. Kerr, Asymmetric Influence in Mock Jury
Deliberation: Jurors’ Bias for Leniency, 54 J. PERSONALITY & SOC. PSYCHOL. 21, 29 (1988). Another
study found a decrease from 65% to 48% for non-deliberating participants. To prevent a confound
between the standard of proof and the presumption of innocence, the 293 jury-eligible participants
were informed that this was an arbitration procedure, not a criminal trial. Simon et al., supra note 145.
154. Glöckner & Engel, supra note 151, at manuscript 6. These data compare the results of the
conditions in which the procedure was described as an arbitration and the standard of proof was the
preponderance of the evidence (Study 1, Treatments 3 and 4, and Study 2, Treatment 4), with the
conditions descried as a criminal procedure with the beyond a reasonable doubt standard (Study 1,
Treatments 1 and 2, and Study 2, Treatment 1). The latter conditions yielded conviction rates that were
less than half of the former conditions (18% v. 44%).
In an early experiment, Lawrence Wrightsman and Saul Kassin found that presenting jurors
with the presumption of innocence and beyond a reasonable doubt standard reduced conviction rates
from 56% to 35% (data for jurors who were given the instructions prior to the evidence). Saul M.
Kassin & Lawrence S. Wrightsman, On the Requirements of Proof: The Timing of Judicial Instruction
and Mock Juror Verdicts, 37 J. PERSONALITY & SOC. PSYCHOL. 1877, 1880 (1979). This finding should
be qualified due to the low number of participants.
155. As one would expect, when the evidence favoring the prosecution was described as strong
No. 2 2012]
LIMITED EFFECTIVENESS OF LEGAL MECHANISMS 193
Yet, even if the standard of proof did reduce conviction rates, it would not
necessarily increase the accuracy of verdicts. The standard is merely a sorting
mechanism, and is devoid of any diagnostic properties of its own. It relies on the
fact finder’s ability to correctly assess the accuracy of evidence in the particular
case. If, as the research suggests, the fact finder’s perception of the defendant’s
guilt does not correspond closely to the actual guilt, the standard can do little to
differentiate guilty from innocent defendants. High standards are thus bound to
result in the acquittal of both innocent and guilty defendants.
The discussion thus far has focused mostly on the performance of individual
jurors. Yet, criminal verdicts are cast collectively by groups, following a process
of deliberation. Vesting the decisionmaking power in the hands of juries
embodies the ideals of a representative and deliberative democracy, and confers
legitimacy on the process.156 The important question for our current purposes is
whether juror deliberation contributes to the accuracy of the decisions made.
The field data pertaining to the effects of deliberation are very instructive.
Post-trial interviews with real-life jurors reveal a very simple yet noteworthy
finding: with very few exceptions, verdicts are determined straightforwardly by
the distribution of votes on the first ballot. In total, in 94% of the cases the
initial majorities won the day.157 An early study by Kalven and Zeisel found that
juries convicted defendants 94% of the time when more than six jurors first
voted for conviction, and acquitted them 97% of the time when fewer than six
jurors voted for conviction on the first ballot.158 Similar findings were made in
studies of 179 criminal trials conducted in Indiana,159 and 43 in Kentucky.160
(ratings of 6 and 7 on a 1–7 scale), the conviction rate was high: 98% of the juries convicted the
defendants and 99% of the judges stated that they would have done the same. Surprisingly, 61% of the
juries voted to convict and 78% of the judges would have done the same when the evidence was
deemed to be of medium strength (ratings of 3, 4, 5). Even more startling is the fact that 17% of the
juries voted to convict when they deemed the evidence to be weak (ratings of 1, 2), and 27% of the
judges would have convicted on the basis of that weak evidence (calculated from data in Table 4 on
page 186). Theodore Eisenberg et al., Judge-Jury Agreement in Criminal Cases: A Partial Replication of
Kalven and Zeisel’s The American Jury, 2 J. EMPIRICAL LEGAL STUD. 171, 188–89 (2005).
156. ABRAMSON, supra note 3, at 3–4; VIDMAR, supra note 3, at 347.
157. These data account for the 222 juries for which detailed data are available. These studies are
summarized in Robert J. MacCoun & Norbert L. Kerr, Is the Leniency Bias Really Dead?
Misinterpreting Asymmetry Effects in Criminal Jury Deliberation (under review 2012) (Table 4, coding
assumption #2). The following analyses will follow the suggestion of Kerr and MaCoun to split the
“undecided” votes on the first ballot evenly between the guilty and not-guilty columns.
158. These data pertain to the non-hanging juries. Sixteen of the trials ended with hung juries. In
the ten cases where the first ballots were split evenly, five ended with a conviction and five with an
acquittal. This study, comprising of 225 criminal cases conducted in Chicago and Brooklyn, was
reported in HARRY KALVEN & HANS ZEISEL, THE AMERICAN JURY, CH. 38 (1966).
159. In this study, the rate of conviction was zero when there were four or fewer votes to convict on
the first ballot, and was 100% when there were eight or more votes to convict. The conviction rate was
around one half (fifty-seven percent) when the first ballot had a majority of no more than two (five to
seven votes to convict). These data exclude the eleven hung juries, and were coded per Robert J.
LAW AND CONTEMPORARY PROBLEMS [Vol. 75:167
Slightly more nuanced relationships between first ballot votes and final verdicts
were found in the NCSC field study.161 The conclusion from these data is that
juries behave democratically not in the nuanced deliberative sense of the term,
but in the blunt majoritarian sense.162 Heroic feats by lone jurors, as depicted in
the classic film Twelve Angry Men, did not occur even once in the thirty-four
cases that began with a split of eleven votes to one on the first ballot.163
Still, the overwhelming power of numeric majorities should not lead to the
conclusion that deliberation has no desirable effect on the process. For one,
deliberation serves the important function of identifying the median votes, thus
eliminating much of the idiosyncratic bias of individual jury members. The
question remains whether deliberation also improves the accuracy of the factual
findings that underlie the verdicts. This is particularly important in cases where
the initial faction splits are close to equal. The contribution of deliberation is
important also to our understanding of what transpires prior to the first ballot
MacCoun & Norbert L. Kerr, Is the Leniency Bias Really Dead? Misinterpreting Asymmetry Effects in
Criminal Jury Deliberation (Table 4, coding assumption #2). These data underestimate the rate of
conviction, as they pertain only to the votes on the most serious charge. Dennis J. Devine, et al.,
Deliberation Quality: A Preliminary Examination in Criminal Juries, 4 J. EMPIRICAL LEGAL STUD. 273,
160. In this study, the rate of conviction was zero when there were four or fewer votes to convict on
the first ballot, and was ninety-four percent when there were eight or more votes to convict. The
conviction rate was sixty-six percent when the first ballot had a majority of no more than two (five to
seven votes to convict). These data exclude the hung juries, and were coded per Kerr & MacCoun,
supra note 159; Marla Sandys & Ronald C. Dillehay, First-Ballot Votes, Predeliberation Dispositions,
and Final Verdicts in Jury Trials, 19 LAW & HUM. BEHAV. 175, 184–85 (1995).
161. In this study, the rate of conviction was 4% when there were four or fewer votes to convict on
the first ballot, and was 94% when there were eight or more votes to convict. The conviction rate was
82% when the first ballot had a majority of no more than two (five to seven votes to convict). These
data exclude the 25 hung juries, and were coded per Kerr & MacCoun. Paula L. Hannaford-Agor, et
al., Are Hung Juries a Problem?, THE NATIONAL CENTER FOR STATE COURTS, 67 (2002),
162. There is some debate among scholars about the existence of a skew towards acquittals
following deliberation, a phenomenon known as “leniency bias,” see generally MacCoun & Kerr, supra
note 153, recently labeled the “asymmetry effects in jury deliberation,” id. at 22. Compare the work of
MacCoun and Kerr with Dennis J. Devine et al., Jury Decision Making: 45 Years of Empirical Research
on Deliberating Groups, 7 PSYCHOL. PUB. POL’Y & LAW 622, Table 6 (2001). To the extent that the
bias exists, it is overwhelmed by the powerful majoritarian dominance. The research is crippled by the
lack of data in the important category of juries that were close to an even split on the first ballot (with
factions of 5:7, 6:6, or 7:5). Of the 222 studies cases, only one jury had an initial split of five jurors
favoring conviction (it voted not guilty), and only four juries had an initial split of 6:6 (three of these
juries voted guilty).
It should be noted that Hastie, Penrod & Pennington (1983) found that juries were just as likely
to shift towards severity as they are towards leniency (for juries governed by a unanimous decision
rule). Mona Lynch & Craig Haney have tested the effects of deliberation in the context of death
penalty sentencing, and found evidence of a “severity shift,” with deliberation increasing death
sentences from 54% to 66%. Lynch & Haney, Discrimination and Instructional Comprehension, supra
note 96, at 485. It should be kept in mind that leniency and severity biases are likely to have the same
effect on guilty and innocent defendants, and thus do not enhance the diagnosticity of the adjudicative
process. Kerr & MacCoun, supra note 143.
No. 2 2012]
LIMITED EFFECTIVENESS OF LEGAL MECHANISMS 195
It is widely intuited that groups outperform their individual members. The
underlying notion is the belief in collective wisdom, which posits that pooling
knowledge and judgment produces the best that the group has to offer and
discards the worst. The research, however, indicates that this belief does not
always correspond with reality. The preponderance of the research suggests that
judgment by groups cannot be said to be generally superior or inferior to the
performance of their individual members.164 On some tasks, groups do indeed
outperform their members.165 On other tasks, however, they perform
comparably,166 or fall short of their members.167 The respective strengths and
weaknesses depend on a host of contextual and group specific factors.168
Crucially, the effect of deliberation on the group’s decision will depend on the
accuracy of the faction that wins the day. Groups are bound to reach correct
conclusions when the prevailing members hold the correct views, but when they
are wrong, deliberation is bound to promote error. Generally speaking,
consensus within groups can be achieved by means of two forms of persuasion:
informational persuasion and social influence, each of which will be discussed in
164. See generally Norbert L. Kerr & R. Scott Tindale, Group Performance and Decision Making,
55 ANN. REV. PSYCHOL. 623 (2004).
165. For example, groups are found to outperform individuals in tasks of general knowledge and
estimation of quantities. See Janet A. Sniezek & Rebecca A. Henry, Accuracy and Confidence in Group
Judgment, 43 ORGANIZATIONAL BEHAV. & HUM. DECISION PROCESSES 1, 20 (1989); Janet A.
Sniezek & Rebecca A. Henry, Revision, Weighting, and Commitment in Consensus Group Judgment, 45
ORGANIZATIONAL BEHAV. & HUM. DECISION PROCESSES 66, 72 (1990).
166. For illustration, a study that tested pairs of participants in solving math puzzles found that
when both members were independently correct or independently wrong, joining forces did not affect
their joint accuracy. The performance of mixed pairs was affected by the deliberation, in that the joint
solution was determined mostly by the member who was more influential—typically, more confident—
irrespective of his or her accuracy. Howard H. Johnson & James M. Torcivia, Group and Individual
Performance on a Single-Stage Task as a Function of Distribution of Individual Performance, 3 J.
EXPERIMENTAL SOC. PSYCHOL. 266, 272 (1967). In performing rule induction problems, groups
perform as well as their best members, but only under optimal conditions. If the information or time is
limited, groups fail to meet that standard. Patrick R. Laughlin et al., Collective Versus Individual
Induction: Recognition of Truth, Rejection of Error, and Collective Information Processing, 61 J.
PERSONALITY & SOC. PSYCHOL. 50, 62 (1991).
167. For example, groups have been found to be more biased than individuals in the search for
information. Stefan Schulz-Hardt et al., Biased Information Search in Group Decision Making, 78 J.
PERSONALITY & SOC. PSYCHOL. 655, 666–67 (2000). Brainstorming is an acute example of the
discrepancy between the widespread belief in the superiority of groups and the empirical findings to the
contrary. On the “illusion of group productivity,” see generally Bernard A. Nijstad, et al., The Illusion
of Group Productivity: A Reduction of Failures Explanation, 36 EUROPEAN J. SOC. PSYCHOL. 31
(2006); Paul B. Pauhus et al., Perception of Performance in Goup Brainstorming: The Illusion of Group
Productivity, 19 PERSONALITY & SOC. PSYCHOL. BULL. 78 (1993).
168. See, e.g., Norbet L. Kerr et al., Bias in Jurors vs Bias in Juries: New Evidence from the SDS
Perspective, 80 ORGANIZATIONAL BEHAV. & HUM. DECISION PROCESSES 70 (1999) [hereinafter Kerr
et al., Bias in Jurors]; Norbet L. Kerr et al., Bias in Judgment: Comparing Individuals and Groups, 103
PSYCHOL. REV. 687 (1996).
169. Morton Deutsch & Harold B. Gerard, A Study of Normative and Informational Social
Influences Upon Individual Judgment, 51 J. ABNORMAL & SOC. PSYCHOL. 629, 634–36 (1955). See
generally Wendy Wood, Motives and Modes of Processing in the Social Influence of Groups, in
DUALPROCESS THEORIES IN SOCIAL PSYCHOLOGY 547 (Shelly Chaiken & Yaacov Trope eds., 1999).
LAW AND CONTEMPORARY PROBLEMS [Vol. 75:167
A. Informational Persuasion
Informational persuasion is performed by means of conveying information
and arguments that lead the listener to alter her position. The research points to
three ways in which the exchange of information among jurors could contribute
to the accuracy of verdicts. One potential contribution of information
persuasion is to improve the jurors’ memory of the evidence presented at trial.
As it is impossible to remember everything presented over the many hours or
days of testimony, jurors enter the deliberation room with memorial accounts
that are incomplete and somewhat idiosyncratic.170 Group deliberation could
prove beneficial either by enhancing memory completeness through the pooling
of the members’ memories or by increasing memory accuracy through the
correction of errors by members with better recall. With respect to the latter,
the research indicates that deliberation hardly affects the accuracy of the
recalled evidence, primarily because most facts recalled by jurors are accurate.171
This is an encouraging finding. The issue of memory completeness, however, is
more complicated. The research reveals that memories produced by
collaborative recall are somewhat more complete than the recall of the average
member, but less complete than the total non-redundant memories recalled by
individual members.172 Studies testing group recall in simulated jury trials
indicate that deliberation offers only a modest improvement to the
completeness of jurors’ memories.173
A second way in which deliberation could conceivably improve the accuracy
of the process is by enhancing individual jurors’ comprehension of the jury
instructions. A large jury simulation conducted by Phoebe Ellsworth found that
deliberating jurors were no more knowledgeable than non-deliberating jurors,
and their comprehension levels were no better than chance. Only half of the
references to legal issues that were expressed during the deliberation were
170. Studies of simulated jurors find that people remember about two-thirds of the relevant details
presented at trial. Mary E. Pritchard & Janice M. Keenan, Does Jury Deliberation Really Improve
Jurors’ Memories?, 16 APPLIED COGNITIVE PSYCHOL. 589, 595 (2002) [hereinafter Pritchard &
Keenan, Jury Deliberation]; Mary E. Pritchard & Janice M. Keenan, Memory Monitoring in Mock
Jurors, 5 J. EXPERIMENTAL PSYCHOL.: APPLIED 152, 158 (1999) [hereinafter Pritchard & Keenan,
Memory Monitoring]. In another study, jurors recalled about sixty percent of the evidence presented.
See HASTIE ET AL., supra note 37.
171. Phoebe C. Ellsworth, Are Twelve Heads Better Than One?, 52 LAW & CONTEMP. PROBS. 205,
224 (Autumn 1989). For similar findings, see Pritchard & Keenan, supra note 170; HASTIE ET AL.,
supra note 37.
172. This phenomenon is labeled “collaborative inhibition.” Mary S. Weldon & Krystal D.
Bellinger, Collective Memory: Collaborative and Individual Processes in Remembering, 23 J.
EXPERIMENTAL PSYCHOL.: LEARNING, MEMORY, AND COGNITION 1160, 1165 (1997). Collaborative
inhibition increases with group size, and is likely to be substantial in groups of twelve members.
Barbara H. Basden et al., Costs and Benefits of Collaborative Remembering, 14 APPLIED COGNITIVE
PSYCHOL. 497, 500 (2000). Groups have been found to have superior memory when tested with
recognition tasks, which are less relevant to the jury setting. See, e.g., Verlin B. Hinsz, Cognitive and
Consensus Processes in Group Recognition Memory Performance, 59 J. PERSONALITY & SOC.
PSYCHOL. 705, 716 (1990).
173. For a review of the research, see Pritchard & Keenan, Jury Deliberation, supra note 170.
Pritchard and Keenan found that group recall was better than recall by individuals by 3.4%. Id. at 600.
No. 2 2012]
LIMITED EFFECTIVENESS OF LEGAL MECHANISMS
correct. When jurors were influenced to alter their understanding of the law,
they were as likely to substitute accurate understandings with errors as they
were to correct mistakes. Opinions expressed most forcefully tended to prevail,
regardless of their accuracy.174 A Canadian study found that in the few instances
in which jurors discussed the judicial instructions, only sixty-one percent of the
statements were legally correct.175 Poor comprehension was also found in studies
of death sentencing instructions. The Missouri juror studies found that
deliberation had a positive, though weak, effect on comprehension of death
penalty instructions in one study and no effect at all in another.176 A study of
California jurors found low comprehension of death penalty instructions
following deliberation.177 Another study found that deliberations improved
comprehension of a death-sentencing instruction that was correctly understood
by two-thirds of the respondents, but not of two other instructions that were
correctly understood only by half or fewer.178 Deliberation could promote
accuracy also by improving jurors’ ability to comply with curative instructions.
Here, too, deliberation yields mixed effects at best. In some instances,
deliberation mitigated the effects of extra-legal evidence.179 Yet in others, it
made no difference,180 and even exacerbated the influence of the impermissible
LAW AND CONTEMPORARY PROBLEMS [Vol. 75:167
Third, jury deliberation could promote verdict accuracy by means of
improving jurors’ ability to draw correct inferences from the evidence. The
limited available research reveals only modest benefits in this regard. Social
psychological studies find that the effect of group deliberation on social
judgments is ameliorative at times, but not always so.182 Studies on deceit
detection found that groups were no more accurate than individuals, though
group members were more confident about their (actually poor) performance.183
B. Social Influence
Informational persuasion is most likely to succeed when there is a
demonstrably correct and evident conclusion,184 which is rare in difficult
criminal cases. In the absence of such favorable conditions, the requisite
unanimity will rely more heavily on social influence.185 Indeed, a distinctive
feature of jury deliberation is that unanimity is often achieved through social
pressure. The prevalence of social pressures is not altogether surprising given
that jury deliberation is a non-structured, non-transparent, one-shot process
among strangers, driven by a strong mandate to reach unanimity in cases that
are often divisive.186 The study by the National Center for State Courts (NCSC)
included interviews with more than 3,000 jurors. These interviews indicate that
the factors that enabled juries to reach a verdict (as opposed to resulting in
hung juries) were predominantly social, not evidential. Reaching consensus was
found to be explainable by factors such as the perceived open-mindedness and
reasonableness of the other jurors, the domination of the deliberation by one or
two jurors, and the degree of conflict on the jury.187 Moreover, this study
Mehrkens Steblay et al., The Effects of Pretrial Publicity on Juror Verdicts: A Meta-Analytical Review,
23 LAW & HUM. BEHAV. 219, 230 (1999).
182. Compare Edward F. Wright & Gary L. Wells, Does Group Discussion Attenuate the
Dispositional Bias?, 15 J. APPLIED SOCIAL PSYCHOL. 531, 542 (1985), with Gwen M. Wittenbaum &
Garold Stasser, The Role of Prior Expectancy and Group Discussion in the Attribution of Attitudes, 31 J.
EXPERIMENTAL SOCIAL PSYCHOL. 82, 99 (1995).
183. In one study, deliberation increased the accuracy rate from 56% to 60%. Groups were found
to be more suspicious and were more inclined to judge the statements as deceitful. Mark G. Frank et
al., Individual and Small Group Accuracy in Judging Truthful and Deceptive Communication, 13
GROUP DECISION & NEGOTIATION 45, 50 (2004). In a second study, deliberation resulted in a
nonsignificant increase in the rate of accuracy from 51.5% to 53%. Ernest S. Park et al., Group and
Individual Accuracy in Deception Detectioni, 19 COMMUNICATION RESEARCH REPORTS 99, 103
(2002). The weak contribution of deliberation is likely due to the low level of individual performance in
the task of deceit detection.
184. Daniel Gigone & Reid Hastie, Proper Analysis of the Accuracy of Group Judgments, 121
PSYCHOL. BULL. 149, 163 (1997).
185. For classic studies on conformity, see Solomon E. Asch, Studies of Independence and
Conformity: I. A Minority of One Against a Unanimous Majority, PSYCHOLOGICAL MONOGRAPHS 70,
186. Jury deliberation lacks discursive conventions that resemble the idealized forms of deliberative
democracy. For example, Jürgen Habermas posits a discourse that aspires to be “public and inclusive,
to grant equal communication rights for participants, to require sincerity and to diffuse any kind of
force other than the forceless force of the better argument.” Jürgen Habermas, Between Facts and
Norms: An Author’s Reflections, 76 DENV. U. L. REV. 937, 940 (1992).
187. These factors were combined to create a Group Dynamics Index, which predicted whether
No. 2 2012]
LIMITED EFFECTIVENESS OF LEGAL MECHANISMS
revealed that the putative unanimity did not reflect genuine consensus. In
almost half of the juries that reached a verdict, at least one juror voted with the
majority against his or her personal judgment.188 Acquiescence of minority
jurors to the will of the majority has also been observed in experimental
studies.189 Jurors who change their mind tend to be the least confident, not the
least accurate.190 The strength of the social pressure tends to increase as the
deliberation progresses,191 and is exacerbated considerably by judicial
instructions designed to undo locked juries, also known as dynamite charges.192
It follows that jury deliberation is potentially beneficial when the influential
jurors have reached valid conclusions, probably detrimental when they are
wrong, and of mixed results when they are evenly split.
Data from laboratory and field studies suggest also that social influence is
affected by the race and gender of the jurors, especially of the forepersons. The
study of the 179 Indiana juries revealed that juries convicted more frequently
when the foreperson voted to convict, especially when the foreperson was white
and male.193 Likewise, studies conducted by the Capital Jury Project have
observed the influence of white male jurors on the likelihood of death
sentences.194 This effect was observed also in a simulated deliberation in a death
Two additional aspects of jury deliberation are of note. First, there is
preliminary evidence that the quality of the deliberation is affected by the jury’s
deliberation style, specifically whether it commences with a discussion of the
juries hung or reached a verdict. The index had a scale reliability of Cronbach’s α = .91.
HannafordAgor et al., supra note 161, at 69.
188. Jurors were asked, “If it were entirely up to you as a one-person jury, what would your verdict
have been in this case?” Nicole L. Waters & Valerie P. Hans, A Jury of One: Opinion Formulation,
Conformity, and Dissent on Juries, 6 J. EMPIRICAL LEGAL STUD. 513, 537 (2009). There is reason to
believe that the true number of silent dissenters is even higher given that people are not inclined to
admit to having defied their own conscience to appease others.
189. See Sarah Tanford & Steven Penrod, Jury Deliberations: Discussion Content and Influence
Processes in Jury Decision Making, 16 J. APPLIED SOCIAL PSYCHOL. 322, 330–31 (1986); Park et al.,
supra note 183, at 103.
190. See Ellsworth, supra note 171, at 220; Pritchard & Keenan, Memory Monitoring, supra note
170, at 165. These findings of social influence are consistent with recent research on “social
vigilantism,” an individual difference construct that corresponds to people’s tendency to impress and
propagate their beliefs onto others and to resist being persuaded in return. See generally Donald A.
Saucier & Russell J. Webster, Social Vigilantism: Measuring Individual Differences in Belief Superiority
and Resistance to Persuasion, 36 PERSONALITY & SOC. PSYCHOL. BULL. 19 (2009).
191. K. L. Hansen et al., Temporal Patterns of Normative, Informational, and Procedural-Legal
Discussion in Jury Deliberations, 14 BASIC & APPLIED SOC. PSYCHOL. 33, 40 (1993).
192. See generally Vicki L. Smith & Saul M. Kassin, Effects of the Dynamite Charge on the
Deliberations of Deadlocked Mock Juries, 17 LAW & HUM. BEHAV. 625 (1993). Saul M. Kassan et al.,
The Dynamite Charge: Effects on the Perceptions and Deliberation Behavior of Mock Juries, 14 LAW &
HUM. BEHAV. 537 (1990).
193. Devine et al., supra note 159, at 283–87.
194. On the white male dominance phenomenon, see William J. Bowers et al., Death Sentencing in
Black and White: An Empirical Analysis of the Role of Juror Race and Jury Racial Composition, 3 U.
PA. J. CONST. L. 171, 195 (2001).
195. Lynch & Haney, supra note 177, at 485.
LAW AND CONTEMPORARY PROBLEMS
evidence (evidence-driven deliberation) or with a vote (verdict-driven
deliberation). The latter style tends to be more argumentative, as jurors
advocate for their espoused verdict. The resulting evaluation of the evidence
tends to be more disjointed, the connections between the law and the facts are
less developed, and the debate is less rigorous and congenial.196 A large field
study of real-life juries found that the juries that took a vote within the first ten
minutes of the deliberation were more likely to hang than juries that
deliberated for longer before their first vote.197 Given the freedom jurors enjoy
in structuring their deliberations in the real world, it is likely that different
juries follow different procedures.
Second, it is important to acknowledge that jury deliberation has a
polarizing effect on the decision. A large body of research shows that discussing
and deciding issues in group settings tends to strengthen people’s positions in
support of the chosen resolution.198 Typically, this polarization results also in
higher levels of confidence.199 Studies of simulated juries find that deliberation
increases jurors’ confidence in their memory of the trial evidence (both accurate
and inaccurate memories),200 in their monitoring of the sources of their
memory,201 and in their judgments of the strength of the evidence.202 As
mentioned, group deliberation has also been found to inflate members’
confidence in judgments of deceit.203
This polarization is bound to have two practical effects. First, polarizing a
fractured jury is likely to deepen the rift between the factions, and thus weaken
the prospect of informational persuasion. This effect, in turn, is bound to
increase the use of social pressure in order to achieve putative unanimity.
Second, jury polarization is likely to drive jurors to feel more strongly about
their initial position. Group polarization has the potential to alter the verdict of
a juror who is moderately leaning towards conviction. The polarization of that
inclination and the concomitant boost in confidence can drive her decision over
the threshold of proof and result in a decision to convict.204
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LIMITED EFFECTIVENESS OF LEGAL MECHANISMS 201
Another legal safeguard that is said to promote the integrity of judicial
outcomes is the subjection of jury verdicts to post-trial review proceedings. The
two common forms of review are the direct appeal process that runs through
higher state courts,205 and the collateral post-conviction proceedings, notably
habeas corpus, that are conducted in federal and state courts. Both processes
are ultimately reviewable by the Supreme Court. Appellate and post-conviction
proceedings provide the opportunity to examine trial court verdicts from a
more detached and authoritative vantage point, and thus have the potential to
increase the diagnosticity of the adjudicative process. Indeed, this review is
generally perceived to be an important guarantee of the integrity of criminal
Yet the access to review by appellate and habeas courts is limited by a range
of procedural barriers. Access to reviewing courts is limited by intricate
statutory and judicially created procedural conditions, which include filing
deadlines, contemporaneous objection at trial, narrow categories of cognizable
claims, and exhaustion of claims.207 Meeting these conditions is a tall order,
especially given that the majority of inmates conduct their post-conviction
affairs without the benefit of legal counsel. Indeed, a recent study found that
federal habeas courts award relief in only 0.4% of non-capital cases they
review,208 and the majority of these reversals were based on legal, not factual,
errors. Appellate and post-conviction courts are strongly averse to intervene in
factual determinations made at the trial level.209 When they do extend
themselves to examine the factual foundation of the verdict, they rely on the
record developed by the trial court and examine the evidence in the light most
favorable to the prosecution,210 which naturally tends to comport with the lower
court’s findings. These courts also apply high thresholds for intervention,211 and
the “coherence effect,” see SIMON, supra note 6, at chs. 2, 6.
205. Convictions for federal crimes are appealed to federal courts of appeal.
206. For example, in the context of capital sentencing, the Supreme Court characterizes the
mandatory review by state supreme courts and its own subsequent review as one of the measures that
“ensure a degree of care . . . that can be described only as unique.” McCleskey v. Kemp, 481 U.S. 279,
207. See, e.g., 28 U.S.C. §§ 2241–2266 (2006); RANDY HERTZ & JAMES S. LIEBMAN, FEDERAL
HABEAS CORPUS PRACTICE AND PROCEDURE, 1707–1898 (5th ed. 2005).
208. The study examined almost 2,400 habeas corpus proceedings conducted in 2003 and 2004.
Among the 267 proceedings in capital cases, some twelve percent of inmates received relief, but only
one third of them pertained to the underlying conviction. NANCY J. KING ET AL., U.S. DEP’T OF
JUSTICE, NAT’L INST. OF JUSTICE, FINAL TECHNICAL REPORT: HABEAS LITIGATION IN THE U.S.
DISTRICT COURTS (2007), available at https://www.ncjrs.gov/pdffiles1/nij/grants/219559.pdf.
209. In habeas proceedings, this deference is imposed by statute. Title 28, section 2254(d) of the
United States Code requires courts to defer to reasonable factual determinations of state courts. As the
Court has stated, “Federal courts are not forums in which to relitigate state trials.” Barefoot v. Estelle,
463 U.S. 880, 887 (1983); see also Sumner v. Mata, 449 U.S. 539, 544 (1981).
210. Jackson v. Virginia, 443 U.S. 307, 318–19 (1979).
211. Hernandez v. New York, 500 U.S. 352, 369 (1991); see also LAFAVE ET AL., CRIMINAL
LAW AND CONTEMPORARY PROBLEMS
entertain only a “sharply limited” review of claims challenging the sufficiency of
evidence.212 For example, the Louisiana Supreme Court has ruled that the
evidence required for post-conviction relief must be new, material,
noncumulative, and conclusive; it must meet “an extraordinarily high standard;”
and it must “undermine the prosecution’s entire case.”213 Finally, cases with
lingering doubts are often punted onto the lap of the executive branch,214 for
whom the political costs of freeing convicted inmates—even ones who are most
likely innocent—is particularly high.215
The meager scope for meaningful review of factual determinations is
manifested by courts’ treatment of the DNA exonerees prior to the discovery of
the exculpating DNA evidence. Brandon Garrett has analyzed the appellate
and post-conviction review that preceded the exoneration in the first 250 DNA
exoneration cases. Of the 165 exoneration cases with written decisions, 69
convicted inmates raised claims challenging the sufficiency of the prosecution’s
evidence, yet only one of these challenges succeeded, only to be reversed later
on. Of the 70 misidentified people who challenged the integrity of the
identification procedures, just five succeeded in undermining the reliability of
the procedures,216 and just one of the thirteen confessors who challenged the
admissibility of their confessions was granted relief.217 Of the thirty-eight DNA
exonerees who petitioned the Supreme Court, just one was granted review, only
to be denied relief. Tellingly, the Court turned down the inmate’s request to
obtain the very piece of evidence that ultimately proved his innocence.218
Overall, the reviewing courts tended not to reveal any qualms about the
underlying convictions. In about one-half of the cases, the courts made
matterof-fact references to the inculpating evidence, occasionally labeling it
PROCEDURE: WEST’S CRIMINAL PRACTICE SERIES 97–98 (3d ed. 2007). A commonly used standard is
whether “any rational trier of fact could have found the essential elements of the crime beyond a
reasonable doubt.” Jackson, 443 U.S. at 318–19.
212. Wright v. West, 505 U.S. 277, 296 (1992). As pointed out by the late William Stuntz, the
preeminence of proceduralism results in a diversion of defense claims from factual to procedural issues.
See William J. Stuntz, The Uneasy Relationship Between Criminal Procedure and Criminal Justice, 107
YALE L.J. 1, 1–76, 37–45 (1997). Ironically, while defense attorneys are all but precluded from
challenging the factual foundation of guilty verdicts, they are regularly derided for insisting on
procedural exactness, or “technicalities.”
213. See State v. Conway, 816 So. 2d. 290, 291 (La. 2002).
214. “Clemency is deeply rooted in our Anglo-American tradition of law, and is the historic remedy
for preventing miscarriages of justice where judicial process has been exhausted.” Herrera v. Collins,
506 U.S. 390, 411–12 (1993).
215. For illustrations of gubernatorial reticence, see the cases of Earl Washington and “The
Norfolk Four.” Earl Washington, THE INNOCENCE PROJECT, http://www.innocenceproject.org/
Content/Earl_Washington.php (last visited 12/1/2011). See also TOM WELLS & RICHARD A. LEO, THE
WRONG GUYS: MURDER, FALSE CONFESSIONS, AND THE NORFOLK FOUR (2008).
216. GARRETT, supra note 4, at Ch. 7.
217. Id. One reversal was awarded for a claim of ineffective assistance of counsel, based on the
lawyer’s failure to challenge the confession at trial. Brandon L. Garrett, The Substance of False
Confessions, 62 STAN. L. REV. 1051, 1107 (2010).
218. Arizona v. Youngblood, 488 U.S. 51 (1988); see also Larry Youngblood, THE INNOCENCE
PROJECT, http://www.innocenceproject.org/Content/303.php (last visited 12/1/2011).
No. 2 2012]
LIMITED EFFECTIVENESS OF LEGAL MECHANISMS 203
“overwhelming.”219 It is also notable that the DNA exonerees were no more
likely to receive relief than a matching group of similarly situated inmates
whose guilt was not refuted by DNA or by any other exonerating evidence (9%
and 10% of non-capital cases, respectively).220
It is troubling to note that many of the innocent convicts did not even
challenge the faulty evidence that led to their convictions. Of those falsely
identified by eyewitnesses, only one contested the identification procedures,
and fewer than two-thirds of those convicted on the basis of a confession
challenged the legality of their interrogations.221 In fact, DNA exonerees did not
challenge their convictions any more than did the inmates in the matching
group (who are presumably guilty).222 Whether the impassivity of these innocent
people was due to a lack of resources, their mistrust of the system, or any other
reason, the reality is that they did not benefit from the legal avenues that were
ostensibly open to them. In short, not unlike the other legal safeguards
discussed above, the post-trial review proceedings provide spare assistance in
distinguishing between truly guilty and factually innocent convicted inmates.
CONCLUSION AND RECOMMENDATIONS FOR REFORM
The research examined in Limited Diagnosticity revealed limitations in the
reliability of the evidence typically presented in criminal trials and in the
capability of fact finders to fulfill their diagnostic task. This article has examined
the extent to which the fact finding task can be improved by the legal
mechanisms put in place to promote the diagnosticity of the process. This
examination paints a mixed, and overall troubling, picture. To a certain extent,
these mechanisms do indeed enhance diagnosticity, but under a wide range of
circumstances, they are ineffective, and even detrimental.
Cross-examination can help in deterring perjury and stumping deceitful
witnesses, but it is ill equipped to prevent honest mistakes. It is also of limited
effectiveness, and can even backfire, especially for litigants who operate with an
informational disadvantage, as defense attorneys often do. Cross-examination
can also hurt the diagnosticity of the process by inducing biased testimony and
flummoxing truthful witnesses. Jury instructions are widely misunderstood and
misapplied, and are oftentimes superseded by the jurors’ personal beliefs about
the law and their conceptions of justice. Jury instructions are particularly
ineffective when they call for mental operations that are unnatural or
unfamiliar. In particular, the poor performance in following instructions casts
serious doubts over the viability of the “guided discretion” regimes by which
death penalties are meted out.
219. Garrett, supra note 4, at ch. 7
220. Each one of the DNA exonerations was matched with a randomly selected conviction for the
same crime, from the same state, decided in the same year. Id.
LAW AND CONTEMPORARY PROBLEMS [Vol. 75:167
The research also indicates that people are not well equipped to assess their
own objectivity; thus, relying on jurors’ assurances of their impartiality amounts
to little more than a hollow gesture. The prosecution’s heightened burdens,
namely the presumption of innocence and the reasonable doubt threshold,
appear to reign in verdicts to some extent, but their overall effects are weaker
and murkier than generally believed. Jury deliberation influences verdict
choices in only a narrow range of cases, and its effects on accuracy are mixed.
Finally, the review of factual findings by appellate and post-conviction courts is
severely curbed by a slew of procedural restrictions, and by a distinct proclivity
to shun factual determinations. As a practical matter, findings made at trial are
impervious to reexamination, even in the face of new compelling evidence to
Together, these two articles lead to the conclusion that the adjudicatory
process has only limited capabilities in distinguishing between accurate and
inaccurate evidence. In light of the high expectations from the adjudicatory
process,223 it is better characterized as “pseudo-diagnostic.” To a large degree,
criminal verdicts are determined at the investigative phase, with the trial serving
primarily as a ritual that delivers more symbolic than real value.224 This
conclusion calls from some specific reforms:
(1) To make the adversarial trial more diagnostic, the informational
asymmetry between the prosecution and the defense should be
(2) Jury instructions ought to be drafted in plain language and provided
in writing. Juror instructions should include an explicit debunking of
common misconceptions and, where possible, concrete examples.
(3) When trial judges are asked to clarify the instructions, they should
provide jurors with helpful explanations rather than merely repeat
the (patently unclear) instructions.
(4) Given the ineffectiveness of curative jury instructions, trial judges
ought to be more assertive in limiting the exposure of jurors to
extra-evidential information and in preempting any other situations
that might require resorting to such instructions.
223. High expectations of accuracy were expressed by respondents in the Jurors’ Beliefs Survey. In
response to a question about the acceptable rate of wrongful convictions, the median response was two
out of one thousand convictions, while the mode response was zero. Simon et al., supra note 124. A
somewhat higher tolerance of error was observed in a smaller survey of 133 college students. These
respondents stated that an acceptable rate of wrongful convictions was 5%, and of wrongful acquittals
8%. Hal R. Arkes & Barbara A. Mellers, Do Juries Meet Our Expectations?, 26 LAW & HUM. BEHAV.
625, 631 (2002).
224. Given the historical development of the common law’s criminal justice process, its limited
diagnosticity is not altogether surprising. As described by John Langbein, the English criminal process
evolved piecemeal, as a series of ad hoc tactical measures intended to balance out the advantages of the
opposing adversaries and to circumvent the disbursement of punishments that were discordant with the
prevailing public sentiment. These historical developments transpired with little concern for the
system’s capacity or propensity to ascertain truth. LANGBEIN, supra note 12, at 306–36.
No. 2 2012]
LIMITED EFFECTIVENESS OF LEGAL MECHANISMS
(5) The Supreme Court ought to acknowledge that the “guided
discretion” doctrine fails to eliminate the prejudicial administration
of the death penalty, and thus violates the Eighth Amendment’s
prohibition on cruel and unusual punishment.
(6) Trial judges should be skeptical of jurors’ assurances of impartiality
and should thus apply greater scrutiny when empanelling jurors.
(7) Jurors should be encouraged to thoroughly deliberate prior to taking
the first vote.
(8) Appellate and habeas courts should be more amenable to taking a
fresh look at the evidence upon a substantial showing of innocence,
and should apply less stringent criteria for assessing convictions.
Yet more sweeping and profound reforms are needed to promote factual
accuracy. These reforms require, foremost, a heightened sensitivity towards the
integrity of the evidence, on which the entire process relies. As discussed in
detail in In Doubt, the primary and antecedent causes for faulty evidence lie in
the police investigation, and the underlying errors are frequently induced by the
investigative procedures used. Thus, the criminal investigation both warrants
improvement and is potentially amenable to it. This makes it a promising venue
for reform.225 Hence, the criminal law debate has much to gain by devoting less
attention to the courtroom and more to the police station, and by looking
beyond constitutional protections and procedural rights towards the actual
quality of the evidence that underlies the entire endeavor. Although
implementing reform across the thousands of police departments is no easy
feat, it is encouraging to note that a number of states and jurisdictions have
already made commendable progress. Notable in this regard are North
Carolina, Illinois, Wisconsin, and New Jersey, states which seem to have
responded to their record of wrongful convictions with critical introspection
rather than with denial and self-justification.226
Many of these reforms can be implemented quite straightforwardly by law
enforcement officials and policymakers at almost any level, from chiefs of local
police departments, through district attorneys, and state and federal
legislatures. Ideally, the effort would also be championed by the judiciary,
especially the Supreme Court, which serves as the final arbiter on people’s
rights and is the only institution that has jurisdiction over all law enforcement
agencies and state courts. Importantly, the Court should abandon its devout and
unflinching protection of the procedural rights, and start caring closely about
225. Any effort to reform of criminal investigations must include substantial revision of the
collection of forensic evidence. See generally NATIONAL RESEARCH COUNCIL, STRENGTHENING
FORENSIC SCIENCE IN THE UNITED STATES: A PATH FORWARD (2009).
226. Reforms of lineup procedures have been put into effect in some ten states, including North
Carolina, New Jersey, Rhode Island, Vermont, and Delaware. Mandatory taping of interrogations has
been implemented North Carolina, Illinois, Wisconsin, and more than another dozen states. See
Reforms by State, THE INNOCENCE PROJECT, http://www.innocenceproject.org/news/LawView5.php
(last visited Dec. 1, 2012).
LAW AND CONTEMPORARY PROBLEMS [Vol. 75:167
the inadequate investigative procedures that it condones and the reliability of
the evidence they produce. Thus, the Court should endorse a robust version of
the “freestanding” conception of due process,227 which should be guided by the
objective of maximizing accuracy.228 In plain language, the Bill of Right’s Due
Process clauses should be understood as providing criminal suspects and
defendants the most basic and genuine form of due process, designed to ensure
that their liberty and life will be deprived only following a process that
minimizes the risk of mistakes to an unavoidable minimum. It must be
acknowledged that the Court does not appear to be heading in this direction.229
One obvious way to enhance the accuracy of the evidence is to ensure that
investigations are conducted with scrupulous adherence to “best-practice
procedures.” Naturally, investigations that follow best practices are bound to
produce more accurate evidence. Recommendations for reform include better
management of the investigative process, and reforms of lineup procedures,
interviews with cooperative witnesses, and interrogations of suspects.230 A
second promising way to enhance the integrity of the evidence is to make
criminal investigations transparent. This can be achieved by creating an
electronic record of all investigative procedures and make the record available
to all parties. The recording should capture all encounters with witnesses and
suspects, including all lineups, interviews, and interrogations.
In In Doubt, I offer a detailed discussion of the advantages of the proposed
reforms and of the hurdles they face. In brief, the investigative record will
effectively freeze the witness’ statements at their raw state, and thereby
minimize the effects of memory decay, contamination, and any biases or
distortions borne by the investigative and pre-trial processes. This should bind
witnesses to their original statements, and also reduce the pressure applied on
them to alter their testimony. The recording of investigations is expected also to
have an ameliorative effect on the investigative process itself, primarily by
increasing investigators’ sense of accountability for the way they conduct their
investigations. Transparency would help ensure that investigators adhere to
best practices by providing law enforcement agencies with a tool for training,
No. 2 2012]
LIMITED EFFECTIVENESS OF LEGAL MECHANISMS 207
oversight, and quality assurance, and it should also help deter police
misconduct. The record is also bound to serve as an informational tool by
capturing forensic details that would otherwise not be collected.
Making the evidence more accurate and transparent is bound to make an
appreciable impact throughout the legal proceedings, starting with the
widespread practice of plea bargaining. Prosecutors should offer plea deals that
are more fair and justified, and defendants should be better able to assess their
situation before signing off on long terms of imprisonment. More accurate and
transparent testimony can be expected to reduce the inclination to sort out
murky facts through the costly, cumbersome, and imprecise process of
litigation. When cases go to trial, the heightened quality of evidence is expected
to reduce the distrust between the adversarial parties, and soften the
contentiousness of the process. The range of plausible claims will be curbed,
with the effect of narrowing the opportunities for unjust prosecutions and
frivolous defenses.231 Prosecutors would be in a position to pursue strong cases
more forcefully, and defense attorneys would be better equipped to defend
innocent defendants and to pursue valid claims of their clients. Freeing police
detectives from excessive court proceedings, hostile cross examinations, and
swearing contests should reduce the adversarial pressures they encounter and
enable them to devote more effort to solving crimes.
Naturally, fact finders will be in a better position to determine the facts
when presented with more accurate accounts of the criminal event. Fact finders
should also benefit from gaining better access to the investigative procedures
used to elicit the testimony. In particular, greater transparency should help fact
finders determine whether the testimony might have been swayed or otherwise
biased by the investigation itself.232 Making plea negotiations and trials more
accurate and less contentious should also result in fewer appeals, habeas
proceedings, civil suits, and damage payouts.
The advantages conferred by recording investigations punctuate the
realization that the methods that were available for the presentation and
preservation of evidence in the eighteenth century in England are not
necessarily the best ways of doing so today.233 The deterioration and
231. Indeed, law enforcement agencies that record interrogations report that the number of
motions to suppress confessions has been reduced dramatically, and in some jurisdictions, has been
eliminated altogether. Thomas P. Sullivan et al., The Case for Recording Police Interrogations, 34
LITIG. 30 (2008).
232. It must, however, be acknowledged that the creation of the electronic record itself can
introduce bias. Factors such as camera perspective, framing, lighting, and editing can shape the
narrative impact of the film. For example, research on taping interrogations has found that focusing the
video camera exclusively on the suspect inflates the perceived voluntariness of the suspect’s statements,
which results in unwarranted trust in coerced confessions. See G. Daniel Lassiter et al., Videotaping
Custodial Interrogations: Toward a Scientifically Based Policy, in POLICE INTERROGATIONS AND
FALSE CONFESSIONS: CURRENT RESEARCH, PRACTICE, AND POLICY RECCOMENDATIONS 143–60
(G. Daniel Lassiter et al. eds., 2010); 14 LEGAL & CRIM. PSYCHOL. 157, 167 (2008). For a review and
recommendations to minimize this phenomenon, see id. at 143–60.
233. For an illuminating view of the development of the English criminal process, see LANGBEIN,
LAW AND CONTEMPORARY PROBLEMS
contamination of testimony en route to the trial, coupled with the technological
capability to memorialize witnesses’ statements, makes the orthodox adherence
to the principle of orality seem arcane and deeply misguided. Historically, the
primacy of oral testimony was based on its perceived superiority over
documentary testimony.234 But that advantage is no longer relevant, as the
synthesized oral testimony given in court fares poorly in comparison with a
digital recording of that witness’s raw statements. The oral presentation of
evidence will better serve the fact-finding goal if witnesses were to testify under
the shadow of their own raw statements, and when need be, the courtroom
testimony were supplemented by those recorded statements.
To be sure, the recommendation to create investigative records is bound to
be met with some resistance from law enforcement agencies.235 These concerns,
however, have been largely dispelled by the experience of law enforcement
agencies in the handful of states and scores of counties that mandate the
practice. The consistent reaction of police personnel and prosecutors in these
jurisdictions is nothing short of enthusiastic support. Transparency has turned
out to be a beneficial tool in the hands of law enforcement, even as it continues
to receive backing from defense attorneys.236
Critics are also likely to resist the sharing of investigative recordings with
the defense, due primarily to fears of exposing witnesses to briber and even
intimidation. While this argument has a kernel of truth, it is grossly overblown.
A number of states, including Arizona, Colorado, New Jersey, and North
Carolina, have implemented regimes that afford substantial discovery, with no
apparent regrets.237 Some states, notably Florida and Vermont, even give
supra note 12.
234. As Jeremy Bentham stated, “oral testimony has a great superiority over written testimony.”
M. DUMONT, A TREATISE ON JUDICIAL EVIDENCE EXTRACTED FROM THE MANUSCRIPTS OF
JEREMY BENTHAM, ESQ. 198 (1825).
235. A fuller discussion of these objections is provided in In Doubt. See SIMON, supra note 6, at ch.
236. As stated by a Minnesota official, the order by the state supreme court to tape interrogations
was “the best thing we’ve ever had rammed down our throats.” Statement of Alan K. Harris, Deputy
Prosecutor Hennepin County, quoted in Thomas P. Sullivan, Electronic Recordings of Custodial
Interrogations: Everybody Wins, 95 J. CRIM. L. & CRIMINOLOGY 1127, 1127 (2005). Likewise, a North
Carolina police chief explains that having “greater documentation and better evidence . . . will be a
greater thing when it comes to successful prosecution of the case.” A survey of 630 active police
investigators found that eighty-one percent of the respondents believed that interrogations ought to be
recorded in full. Saul M. Kassin et al., Police Interviewing and Interrogation: A Self-Portrait Survey of
Police Practices and Beliefs, 31 LAW & HUM. BEHAV. 381, 393 (2007).
For a critique of the FBI’s arguments, see Thomas P. Sullivan, Recording Federal Custodial
Interviews, 45 AM. CRIM. L. REV. 1297, 1315–36 (2008). Undoubtedly, some investigations will go
unrecorded. This could occur due to equipment failure, witness non-cooperation, or police misconduct.
Based on the experience with taping of custodial interrogations, there is reason to believe that the
majority of investigations will be taped, primarily because the police will be motivated to do so.
Thomas P. Sullivan & Andrew W. Vail, The Consequences of Law Enforcement Officials’ Failure to
Record Custodial Interviews as Required by Law, 99 J. CRIM. L. & CRIMINOLOGY 215, 221 (2009).
237. For a discussion, see Expanded Discovery in Criminal Cases; A Policy Review, THE JUSTICE
PROJECT (2007), http://www.pewtrusts.org/uploadedFiles/wwwpewtrustsorg/Reports/Death_penalty_
LIMITED EFFECTIVENESS OF LEGAL MECHANISMS 209
criminal defendants the right to depose the prosecution’s witnesses ahead of the
trial.238 These states do not appear to show any of the calamities predicted by
the critics of such policies.239
20. IRVING YOUNGER , THE ART OF CROSS-EXAMINATION 23 (Am. Bar Ass'n Section of Litig ., The Section of Litig. Monograph Ser. No. 1 , 1976 ).
21. On the case of Brady v . Maryland , 373 U.S. 83 , 87 ( 1963 ), and its progeny, see Daniel S. Medwed, Brady's Bunch of Flaws, 67 WASH . & LEE L. REV . 1533 , 1533 - 67 ( 2010 ) ; Scott E. Sundby, Fallen Superheroes and Constitutional Mirages: The Tale of Brady v . Maryland , 33 MCGEORGE L. REV . 643 , 643 - 63 ( 2002 ).
22. For findings of backfiring effects, see Derek D . Rucker & Richard E. Petty, Effects of Accusations on the Accuser: The Moderating Role of Accuser Culpability, 29 PERSONALITY & SOC. PSYCHOL. BULL . 1259 ( 2003 ).
23. A study found that an innuendo inserted by the defense attorney during cross-examination had a negative impact on jurors' evaluations of the testimony of an expert witness, but not of the victim . Saul M. Kassin et al., Dirty Tricks of Cross-Examination: The Influence of Conjectural Evidence on the Jury, 14 LAW & HUM. BEHAV . 373 , 380 - 81 ( 1990 ).
24. This danger was observed by Jerome Frank and Marvin E. Frankel. JEROME FRANK , COURTS ON TRIAL 82 ( 1949 ) and MARVIN E. FRANKEL, PARTISAN JUSTICE 75 ( 1978 ).
25. Monroe H. Freedman , Professional Responsibility of the Criminal Defense Lawyer: The Three Hardest Questions , 64 MICH. L. REV. 1469 , 1475 - 76 ( 1966 ).
26. Tim Valentine & Katie Maras , The Effect of Cross-Examination on the Accuracy of Adult Eyewitness Testimony, 25 APPLIED COGNITIVE PSYCHOL . 554 , 559 ( 2011 ).
27. Mark R. Kebbell & Shane D. Johnson , Lawyers' Questioning: The Effect of Confusing Questions on Witness Confidence and Accuracy, 24 LAW & HUM. BEHAV . 629 , 634 , 637 ( 2000 ); Nancy W. Perry et al., When Lawyers Question Children: Is Justice Served?, 19 LAW & HUM. BEHAV . 609 , 625 - 26 ( 1995 ). The latter experiment found that convoluted questions had adverse effects of subjects in four age groups ranging from kindergarten to college .
45. Ogloff , supra note 37.
46. See NORMAN J. FINKEL , COMMONSENSE JUSTICE : JURORS' NOTIONS OF THE LAW ch . 17 ( 1995 ) ; PAUL H. ROBINSON & JOHN M. DARLEY , JUSTICE, LIABILITY , & BLAME ch . 7 ( 1995 ) ; Saul M. Kassin & Samuel R. Sommers , Inadmissible Testimony, Instructions to Disregard, and the Jury: Substantive Versus Procedural Considerations, 23 PERSONALITY & SOC. PSYCHOL. BULL . 1046 , 1051 ( 1997 ).
47. Vicki L. Smith , Prototypes in the Courtroom: Lay Representations of Legal Concepts , 61 J. PERSONALITY & SOC. PSYCHOL . 857 ( 1991 ) ; Vicki L. Smith, When Prior Knowledge and Law Collide: Helping Jurors Use the Law, 17 LAW & HUM . BEHAV. 507 , 533 ( 1993 ).
48. Mandeep K. Dhami , On Measuring Quantitative Interpretations of Reasonable Doubt, 14 J. EXPERIMENTAL PSYCHOL.: APPLIED 353 ( 2008 ).
49. A study with federal and state judges observed that the judges were more likely to follow the law and ignore a confession obtained through an impermissibly coercive interrogation when the suspect was charged with a less serious offense than when the offense was more serious . Jeffrey J . Rachlinski et al., Context Effects in Judicial Decision Making (forthcoming).
50. See generally Richard M. Wenzlaff & Daniel M. Wegner , Thought Suppression, 51 ANN. REV. PSYCHOL . 59 ( 2000 ).
51. See , e.g., Kerri L. Pickel, Inducing Jurors to Disregard Inadmissible Evidence: A Legal Explanation Does Not Help , 19 LAW & HUM . BEHAV. 407 , 422 - 23 ( 1995 ) ; Sharon Wolf & David A. Montgomery , Effects of Inadmissible Evidence and Level of Judicial Admonishment to Disregard on the Judgments of Mock Jurors, 7 J . APPLIED SOC. PSYCHOL . 205 , 207 ( 1977 ).
52. See Jack W. Brehm & John Sensenig, Social Influence as a Function of Attempted and Implied Usurpation, 4 J . PERSONALITY & SOC. PSYCHOL . 703 , 703 - 07 ( 1966 ).
53. See generally Baruch Fischhoff, Hindsight-Foresight: The Effect of Outcome Knowledge on Judgment Under Uncertainty, 1 J. EXPERIMENTAL PSYCHOL . : HUM. PERCEPTION & PERFORMANCE 288 ( 1975 ).
54. See generally Craig A. Anderson et al., Perseverance of Social Theories: The Role of Explanation in the Persistence of Discredited Information, 39 J. PERSONALITY & SOC. PSYCHOL . 1037 ( 1980 ).
55. See generally Nancy Steblay et al., The Impact on Juror Verdicts of Judicial Instruction to Disregard Inadmissible Evidence: A Meta-Analysis, 30 LAW & HUM . BEHAV. 469 ( 2006 ).
56. Kassin & Sommers, supra note 46.
57. Steven Fein et al., Can the Jury Disregard that Information? The Use of Suspicion to Reduce the Prejudicial Effects of Pretrial Publicity and Inadmissible Testimony, 23 PERSONALITY & SOC. PSYCHOL. BULL . 1215 , 1223 ( 1997 ).
58. Admonitions were found to be ineffective when the evidence to be ignored contained a recording of the defendant's admission of guilt, provided key facts about an obscure homicide, or connected the defendant's gun to the crime . See Saul M. Kassin & Holly Sukel, Coerced Confessions and the Jury: An Experimental Test of the ”Harmless Error” Rule, 21 LAW & HUM . BEHAV. 27 , 43 ( 1997 ); Christine L. Ruva & Cathy McEvoy , Negative and Positive Pretrial Publicity Affect Juror Memory and Decision Making, 14 J . EXPERIMENTAL PSYCHOL.: APPLIED 226 , 232 ( 2008 ) ; Stanley Sue et al ., Biasing Effects of Pretrial Publicity on Judicial Decisions , 2 J. CRIM . JUST. 163 , 170 ( 1974 ); Fein et al., supra note 57.
59. Kassin & Sommers, supra note 46.
60. Sue et al., supra note 58.
61. Instructions to ignore hearsay evidence-which can be seen as lying in the gray area of popular conceptions of justice-yield mixed results. Such instructions were unsuccessful in the study by Fein et al ., supra note 57 , at 1223, but generally successful in the study by Pickel , supra note 51 , at 419.
62. Andrew J. Wistrich et al., Can Judges Ignore Inadmissible Information? The Difficulty of Deliberately Disregarding , 153 U. PA. L. REV . 1251 , 1323 ( 2005 ).
63. Federal Rule of Evidence 404(b) instructs that “[e]vidence of other crimes, wrongs, or acts is not admissible to prove the character of a person in order to show action in conformity herewith.” Yet, Federal Rule of Evidence 609(a) instructs that under some conditions, evidence of prior convictions can be admitted for the purpose of “attacking a witness's character for truthfulness . ” Rule 404 ( b) itself also offers exceptions that permits evidence of other crimes, wrongs, or acts is for “other purposes, such as proof of motive, opportunity, intent, preparation, plan, knowledge, identity, or absence of mistake or accident .”
64. FED . R. EVID. 105 .
65. See , e.g., Patricia G . Devine, Stereotypes and Prejudice: Their Automatic and Controlled Components, 56 J. PERSONALITY & SOC. PSYCHOL . 5 ( 1989 ); Daniel T. Gilbert, Ordinary Personology, in 2 HANDBOOK OF SOCIAL PSYCHOLOGY 89 ( Daniel T. Gilbert et al. eds., 4th ed. 1998 ); James S. Uleman et al., Spontaneous Inferences , Implicit Impressions, and Implicit Theories, 59 ANN. REV. PSYCHOL . 329 , 332 ( 2008 ).
66. John A. Bargh, The Four Horsemen of Automaticity: Awareness, Intention, Efficiency, and Control in Social Cognition, in 1 HANDBOOK OF SOCIAL COGNITION 1 (Robert S. Wyer , Jr. & Thomas K . Srull eds., 2d ed. 1994 ).
67. Anthony N. Doob & Hershi M. Kirshenbaum , Some Empirical Evidence of the Effect of Section 12 of the Canada Evidence Act upon the Accused, 15 CRIM . L.Q. 88 , 94 - 96 ( 1972 ) ; Edith Greene & Mary Dodge, The Influence of Prior Record Evidence on Juror Decision Making, 19 LAW & HUM . BEHAV. 67 , 72 - 73 ( 1995 ); Valerie P. Hans & Anthony N. Doob , Section 12 of the Canada Evidence Act and the Deliberations of Simulated Juries, 18 CRIM . L.Q. 235 , 242 ( 1976 ); Roselle L. Wissler & Michael J. Saks , On the Inefficacy of Limiting Instructions: When Jurors Use Prior Conviction Evidence to Decide on Guilt, 9 LAW & HUM . BEHAV. 37 , 41 - 42 ( 1985 ). Simulated jurors are somewhat more responsive to limiting instructions when the prior and current charges pertain to different crimes . See Wissler & Saks, supra note 67 . The likely reason is that the intuitive assumptions of recidivism do not hold so strongly between different types of criminal behavior .
68. See generally Steblay et al., supra note 55.
69. Compare Wissler & Saks, supra note 67, with Sarah Tanford & Michele Cox , The Effects of Impeachment Evidence and Limiting Instructions on Individual and Group Decision Making, 12 LAW & HUM. BEHAV . 477 , 488 ( 1988 ).
70. Jennifer S. Hunt & Thomas Lee Budesheim, How Jurors Use and Misuse Character Evidence, 89 J. APPLIED PSYCHOL . 347 , 359 ( 2004 ).
71. See Edith Greene & Elizabeth F. Loftus , When Crimes Are Joined at Trial, 9 LAW & HUM. BEHAV . 193 , 203 - 04 ( 1985 ).
72. Krulewitch v. United States , 336 U.S. 440 , 453 ( 1949 ).
73. Nash v. United States , 54 F.2d 1006 , 1007 ( 2d Cir . 1932 ).
74. United States v. Grunewald , 233 F.2d 556 , 574 ( 2d Cir . 1956 ).
75. Sandez v. United States , 239 F.2d 239 , 248 ( 9th Cir . 1956 ).
76. Dunn v. United States , 307 F.2d 883 , 886 ( 5th Cir . 1962 ).
77. Exceptions are made only in face of an “overwhelming probability” that the jury will be unable to do so and there is a “strong likelihood that the effect of the evidence would be 'devastating' to the defendant.” Greer v . Miller , 483 U.S. 756 , 767 ( 1987 ) (citations omitted); Richardson v . Marsh , 481 U.S. 200 ( 1987 ). But see Cruz v . New York, 481 U.S. 186 ( 1987 ).
78. A meta-analysis showed that decisions to admit the contested evidence result in rates of conviction that are 50% higher than when the evidence is ruled inadmissible and followed by an instruction to ignore (74% v . 46 %). Steblay et al., supra note 55 , at 479.
86. Haney & Lynch, Clarifying Life and Death Matters, supra note 84.
87. California 's new pattern instructions, CALCRIM, were adopted by Judicial Council in 2005 and came into effect in 2006. The primary innovation in these instructions is the use of psycholinguistic principles to simplify the language of the instructions .
88. Even with the best instructions, lay people reach comprehension scores that are below half of the correct responses . Amy E. Smith & Craig Haney , Getting to the Point: Attempting to Improve Juror Comprehension of Capital Penalty Phase Instructions, 35 LAW & HUM . BEHAV. 339 , 347 - 49 ( 2011 ).
89. Richard L. Wiener et al., Comprehensibility of Approved Jury Instructions in Capital Murder Cases, 80 J. APPLIED PSYCHOL . 455 , 459 ( 1995 ).
90. Richard L. Wiener et al., The Role of Declarative and Procedural Knowledge in Capital Murder Sentencing, 28 J. APPLIED SOC. PSYCHOL . 124 , 13 ( 1998 ); Richard L. Wiener et al., Guided Jury Discretion in Capital Murder Cases: The Role of Declarative and Procedural Knowledge, 10 PSYCHOL . PUB. POL' Y & L. 516 , 570 ( 2004 ) [hereinafter Wiener et al ., Guided Jury Discretion].
91. Only 40% of these respondents correctly understood the rule regarding the non-enumerated mitigating factors, and 33% miscomprehended the non-unanimity rule for mitigating factors . Shari S. Diamond & Judith N. Levi , Improving Decisions on Death by Revising and Testing Jury Instructions, 79 JUDICATURE 224 , 230 ( 1996 ).
92. The overall rate of correct responses in this study was 47.5% (for death-eligible respondents) . Charles W. Otto et al., Improving Comprehension of Capital Sentencing Instructions: Debunking Juror Misconceptions , 53 CRIME & DELINQ. 502 , 509 ( 2007 ).
93. James Frank & Brandon K. Applegate , Assessing Juror Understanding of Capital-Sentencing Instructions, 44 CRIME & DELINQ. 412 , 419 ( 1998 ).
94. Correct responses ranged from 22% to 83%, with most values around the 50% accuracy . Michael B. Blankenship et al., Jurors' Comprehension of Sentencing Instructions: A Test of the Death Penalty Process in Tennessee, 14 JUST . Q. 325 , 334 - 39 ( 1997 ).
120. In re Winship, 397 U.S. 358 , 372 ( 1970 ).
121. 4 WILLIAM BLACKSTONE , COMMENTARIES * 358 .
122. Bell v. Wolfish , 441 U.S. 520 ( 1979 ). For an expansive view of the presumption of innocence, see Keith A . Findley , Defining Innocence, 74 ALB. L. REV. 1157 , 1194 ( 2011 ). On the presumption's possible expressive function as a means of punctuating the respect that society places on the freedoms and reputations of its members, see Laurence H . Tribe, Trial By Mathematics: Precision and Ritual in the Legal Process , 84 HARV. L. REV. 1329 , 1370 ( 1972 ).
123. For example, the Connecticut pattern jury instructions explain that at the beginning of the trial, the defendant “stood before you free of any bias, prejudice or burden arising from his position as the accused .” 5 DAVID M. BORDEN & LEONARD ORLAND , CONNECTICUT PRACTICE SERIES, CRIMINAL JURY INSTRUCTIONS § 2 .8 (4th ed. 2011 ). This view was espoused by the Supreme Court in Bell v . Wolfish . 441 U.S. 520 , 533 ( 1979 ).
124. Dan Simon et al., Professor of Law and Psychology , Univ. of S. Cal., American PsychologyLaw Society Annual Conference: Jurors' Background Knowledge and Beliefs (Mar . 6- 8 , 2008 ).
125. Half of these respondents interpreted the charges as “strong evidence” of guilt. Bradley Saxton, How Well do Jurors Understand Jury Instructions? A Field Test Using Real Juries and Real Trials in Wyoming, 33 LAND & WATER L. REV . 59 , 101 ( 1998 ).
126. Vicki S. Helgeson & Kelly G. Shaver , Presumption of Innocence: Congruence Bias Induced and Overcome, 20 J. APPLIED SOC. PSYCHOL . 276 , 289 - 96 ( 1990 ).
127. Thomas M. Ostrom et al., An Integration Theory Analysis of Jurors' Presumptions of Guilt or Innocence, 36 J. PERSONALITY & SOC. PSYCHOL . 436 , 445 - 46 ( 1978 ).
128. Strawn & Buchanan, supra note 38, at 481.
129. The accuracy of non-instructed jurors was even lower, suggesting that the instruction had a moderately positive impact on comprehension . Raymond W. Buchanan et al., Legal Communication: An Investigation of Juror Comprehension of Pattern Instructions, 26 COMMUNICATION MONOGRAPHS 31 , 34 ( 1978 ).
130. Some twenty percent of the respondents stated that once the state has made its case, it becomes the defendant's responsibility to provide proof that he did not commit the crime . Saxton, supra note 125 , at 97.
131. A majority of these jurors had recently served as jurors in a criminal trial . Reifman et al., supra note 39 , at 546-47.
132. Strawn & Buchanan, supra note 38.
133. Legal historian James Whitman argues that the term was not originally intended as a standard
143. Jackson v. Virginia , 443 U.S. 307 , 315 ( 1979 ).
144. The definition included “real tangible substantial basis,” not “caprice and conjecture,” not “give rise to a grave uncertainty,” not “a mere possible doubt,” “actual and substantial,” “reasonable man can seriously entertain,” not “an absolute or mathematical certainty,” and “moral certainty .” Cage v. Louisiana , 498 U.S. 39 , 41 ( 1990 ). The Court struck down the instruction, but not because of its potential to confuse jurors . Id.
145. See , e.g., Norbet L. Kerr et al., Guilt Beyond a Reasonable Doubt: Effects of Concept Definition and Assigned Decision Rule on the Judgments of Mock Jurors , 34 J. PERSONALITY & SOC. PSYCHOL . 282 , 293 ( 1976 ) (finding an average assessment of eighty-seven percent). A study of 134 jury-eligible Internet users found an average assessment of 84.5% . Simon et al., Lay Assessments of Standards of Proof (unpublished data).
146. The value of 90% (or 91%) is frequently said to be derived from Blackstone's error-ratio of 10:1. That inference is mistaken. To derive the standard of proof from the error ratio, one would need also to know the base rate of guilt among the prosecuted cases and the jury's diagnostic capabilities . See Michael L. DeKay, The Difference Between Blackstone-Like Error Ratios and Probabilistic Standards of Proof, 21 L. & SOC. INQUIRY 95 , 103 - 10 ( 1996 ).
147. Greene & Dodge, supra note 67, at 75.
148. Irwin A. Horowitz & Laird C. Kirkpatrick , A Concept in Search of a Definition: The Effects of Reasonable Doubt Instructions on Certainty of Guilt Standards and Jury Verdict, 20 LAW & HUM . BEHAV. 655 , 670 - 71 ( 1996 ).
149. Kramer & Koenig, supra note 41, at 414.
150. James R. P. Ogloff & V. Gordon Rose, THE COMPREHENSION OF JUDICIAL INSTRUCTIONS, in PSYCHOLOGY AND LAW: AN EMPIRICAL PERSPECTIVE 418 (Neil Brewer & Kipling D . Williams eds., 2005 ).
151. Some 40% of a sample of German respondents stated a threshold of 95-99% . Andreas Glöckner & Christoph Engel, Can We Trust Intuitive Jurors? Standards of Proof and the Probative Value of Evidence in Coherence Based Reasoning , J. EMPIRICAL LEGAL STUD . (forthcoming 2012 ) (manuscript at 4).
174. See Ellsworth, supra note 171.
175. See Ogloff & Rose, supra note 150 (describing a study of juries and jury instructions in Canada) .
176. Wiener et al., Guided Jury Discretion, supra note 90 , at 571.
177. Mona Lynch & Craig Haney , Capital Jury Deliberation: Effects on Death Sentencing, Comprehension, and Discrimination, 33 LAW & HUM. BEHAV . 481 , 489 ( 2009 ).
178. Diamond & Levi, supra note 91.
179. One study found that deliberation reduced guilt ratings following a judge's admonition to disregard inadmissible evidence (5.7 to 4.4 on a scale ranging from 1 to 9 ). Jeffrey Kerwin & David R. Shaffer , Mock Jurors Versus Mock Juries: The Role of Deliberation in Reactions to Inadmissible Testimony, 20 PERSONALITY & SOC. PSYCHOL. BULL . 153 , 159 ( 1994 ). Another study found that deliberation halved conviction rates given by admonished jurors . Kamala London & Narina Nunez, The Effect of Jury Deliberations on Jurors' Propensity to Disregard Inadmissible Evidence, 85 J. APPLIED PSYCHOL . 932 , 934 ( 2000 ).
180. In one study, deliberation was found to reduce admonished jurors' conviction rates by a mere five percent . Valerie P. Hans & Anthony N. Doob , Section 12 of the Canada Evidence Act and the Deliberations of Simulated Juries, 18 CRIM . L.Q. 235 , 243 ( 1976 ). Deliberation did not make a difference in a study that exposed jurors to pre-trial publicity in a murder case . Christine Ruva et al., Effects of Pre-Trial Publicity and Jury Deliberation on Juror Bias and Source Memory Errors, 21 APPLIED COGNITIVE PSYCHOL . 45 , 58 ( 2007 ). Similarly, deliberation and admonitions made no effect on reducing the hindsight bias in an automobile negligence trial . Alison C. Smith & Edith Greene, Conduct and Its Consequences: Attempts at Debiasing Jury Judgments, 29 LAW & HUM . BEHAV. 505 , 524 ( 2005 ).
181. In a study simulating a child molestation charge, jurors presented with inadmissible pre-trial publicity were considerably more likely to convict the defendant following deliberation than they were prior to it (29% v . 11 %). This result was obtained where the evidence was ambiguous, which is the most forensically relevant type of situation . Kerr et al., Bias in Juries, supra note 168 , at 79. A large study found that pre-trial publicity affected judgments only following deliberation, increasing convictions from 6% to 20% . Geoffrey P. Kramer et al., Pretrial Publicity , Judicial Remedies, and Jury Bias, 14 LAW & HUM. BEHAV . 409 , 424 ( 1990 ). A limited number of deliberation studies included in the metaanalysis of pre-trial publicity show that deliberation served no appreciable curative effect . Nancy
196. HASTIE ET AL., supra note 37.
197. Hannaford-Agor et al., supra note 161.
198. For reviews, see Daniel J. Isenberg, Group Polarization: A Critical Review and Meta-Analysis , 50 J. PERSONALITY & SOC. PSYCHOL . 1141 , 1142 ( 1986 ) ; CASS R. SUNSTEIN , WHY GROUPS GO TO EXTREMES ( 2008 ).
199. Sniezek & Henry, supra note 165, at 79. Confidence inflation is strongest in tasks that lack demonstrably correct conclusions . Paul Zarnoth & Janet A. Sniezek , The Social Influence of Confidence in Group Decision Making, 33 J. EXPERIMENTAL SOC. PSYCHOL . 345 , 361 ( 1997 ).
200. Pritchard & Keenan, Jury Deliberation, supra note 170 , at 597.
201. Ruva et al., supra note 180 , at 48.
202. Martin F. Kaplan & Lynn E. Miller , Reducing the Effects of Juror Bias, 36 J. PERSONALITY & SOC. PSYCHOL . 1443 , 1448 - 49 ( 1978 ).
203. One study found that deliberation increased the confidence of group members from 81% to 89% . Park et al., supra note 183 , at 53. Another study found that the confidence of members of deliberating groups was higher than that of individuals . Frank et al., supra note 183 , at 103.
204. The effect of polarization on jurors who are inclined to acquit is unlikely to have an effect on the juror's vote. Due to the asymmetric standard of proof, a juror leaning towards acquittal should vote to acquit regardless of the strength of that leaning. For a similar, intrapersonal polarization borne by
227. See generally Jerold H. Israel , Free-standing Due Process and criminal procedure: The Supreme Court's Search for Interpretive Guidelines, 45 ST . LOUIS U. L.J. 303 ( 2001 ) ; Andrew E. Tazlitz, What Remains of Reliability: Hearsay and Freestanding Due Process After Crawford v . Washington, CRIM. JUSTICE, Summer 2005 , at 39.
228. DONLAD A. DRIPPS, ABOUT GUILT AND INNOCENCE: THE ORIGINS, DEVELOPMENT, AND FUTURE OF CONSTITUTIONAL CRIMINAL PROCEDURE ( 2003 )
229. At the oral arguments in Perry v . New Hampshire (No. 10 - 8974 , November 2, 2011 ), the justices seemed resolutely averse to the concept of freestanding due process rights . See Dahlia Lithwick , See No Evil: Eyewitness Testimony May be Unreliable, but the Supreme Court Doesn't Want to be the One to Say So , SLATE (Nov. 02 , 2011 ), http://www.slate.com/articles/news_and_politics/ supreme_court_dispatches/ 2011 /11/perry_v_ new_hampshire_the_supreme_court_looks_at_eyewitness_ evid.single.html. The case dealt with the admissibility of an eyewitness identification that was obtained from a suggestive lineup, which is the most notable application of a freestanding due process right . See Manson v. Brathwaite , 432 U.S. 98 ( 1977 ).
230. See Simon, supra note 6 , at chs. 2- 5