Reliability Under Rule 702: A Specialized Application of 403

Reliability Under Rule 702: A Specialized Application of 403 Calvin William Sharpe∗ The concern for witness reliability is not new to Evidence law. Since the Anglo-American adversarial system relies for accurate factfinding upon jurors who have no independent knowledge of the facts at issue, it is important for witnesses supplying evidence that will form 1 the basis of such fact-finding to be reliable. Evidentiary submissions 2 3 that raise issues of hearsay, first-hand knowledge, original 4 documents, and others invoke rules that reflect a concern about reliability. Expert testimony raises the same concern under Rule 5 702. ∗ John Deaver Drinko—Baker & Hostetler Professor of Law, Case Western Reserve University Law School. The author is grateful to Margaret Skarbek for helpful research assistance on this paper. This research was made possible by a grant from Case Western Reserve University Law School. 1 RONALD J. ALLEN ET AL., EVIDENCE: TEXT, PROBLEMS, AND CASES § 204 (3d ed. 2002). 2 See FED. R. EVID. art. VIII, advisory committee’s introductory note (noting as a purpose of the hearsay rule “to encourage the witness to do his best with respect to each of [the factors of perception, memory, narration, and sincerity], and to expose any inaccuracies which may enter in”). 3 See FED. R. EVID. 602 advisory committee’s note (citing McCormick for the following passage in describing the justification for the rule: “‘[T]he rule requiring that a witness who testifies to a fact which can be perceived by the senses must have had an opportunity to observe, and must have actually observed the fact’ is a ‘most pervasive manifestation’ of the common law insistence upon ‘the most reliable sources of information.’”). 4 See FED. R. EVID. 1001 advisory committee’s note (noting that the best evidence “afforded substantial guarantees against inaccuracies and fraud”); see also 2 MCCORMICK ON EVIDENCE 229 (John W. Strong ed., 5th ed. 1999) (noting “the danger of mistransmitting critical facts which accompanies the use of written copies or recollection”). 5 See Daubert v. Merrell Dow Pharm., Inc., 509 U.S. 579, 591-92 (1993) (noting the concern of the common law with reliable sources of information as manifested in the personal knowledge and hearsay rules and explaining that the reliability requirement in 702 grows out of a concern about the wide latitude permitted the expert witness whose opinions need not be based on firsthand knowledge or observation). 289 290 SETON HALL LAW REVIEW Vol. 34:289 In any of these contexts, perfectly reliable evidence would justify the jury’s absolute confidence in the truth of its contents and provide complete support for reasonable inferences to be drawn from the 6 evidence. Some cross-examination and all impeachment are efforts to diminish the perceived reliability of evidence in the hope that a 7 fact-finder will discount its value. THE LAW The Supreme Court in Daubert v. Merrell Dow Pharmaceuticals, 8 9 10 Inc., General Electric Co. v. Joiner, and Kumho Tire Co. v. Carmichael, and Congress in Rule 702 as amended in 2000, have attempted to delineate the parameters of reliable expert testimony. Even before the 2000 amendments the concept of reliability was embedded in Rule 702. That rule permitted an expert to give helpful scientific, technical, or other specialized knowledge. It is the concept of knowledge in Rule 702 that embodied the idea of reliability as truth. The Supreme Court unearthed the buried idea of reliability in 11 Daubert. In dispelling the notion of general acceptance as a prerequisite to the admissibility of scientific evidence, the Court expressed the assurance that admissibility of scientific evidence was 12 not unlimited. It spelled out a judge’s screening function in such cases as involving the dual determination of relevancy and 13 reliability. Since Daubert involved scientific evidence, the Court in the following terms discerned the reliability requirement in 702’s language sanctioning expert testimony about scientific knowledge: The subject of an expert’s testimony must be “scientific . . . knowledge.” The adjective “scientific” implies a grounding in the 6 See 13 THE OXFORD ENGLISH DICTIONARY 562 (2d ed. 1989) (defining “reliable” as “1.a. That may be relied upon; in which reliance or confidence may be put; trustworthy, safe, sure”). It also defines “trust” as “[c]onfidence in or reliance on some quality or attribute of a person or thing, or the truth of a statement . . . .” 18 Id. at 623. 7 See In re Paoli R.R. Yard PCB Litig. (Paoli II), 35 F.3d 717 (3d Cir. 1994) (stating that credibility may have a bearing on the reliability of expert testimony); ALLEN ET AL., supra note 1, at 108-09, 389-90. 8 509 U.S. 579 (1993). 9 522 U.S. 136 (1997). 10 526 U.S. 137 (1999). 11 But see Paul C. Giannelli, Daubert: Interpreting The Federal Rules of Evidence, 15 CARDOZO L. REV. 1999, 2015 (1994) (noting that the reliability approach developed five to seven years after the enactment of the rules and commenting that “there is an element of magic in the [Daubert] Court’s ‘discovery’ of [the reliability] analysis in Rule 702’s phrase ‘scientific knowledge’”). 12 509 U.S. at 589. 13 Id. 2003 RELIABILITY UNDER RULE 702 291 methods and procedures of science. Similarly, the word “knowledge” connotes more than subjective belief or unsupported speculation. The term “applies to any body of known facts or to any body of ideas inferred from such facts or 14 accepted as truths on good grounds.” That the “good grounds” (reliability) supporting scientific knowledge are derived from the scientific method is expressed as follows: [I]n order to qualify as “scientific knowledge,” an inference or assertion must be derived by the scientific method. Proposed testimony must be supported by an appropriate validation—i.e., “good grounds,” based on what is known. In short, the requirement that an expert’s testimony pertain to ‘scientific 15 knowledge” establishes a standard of evidentiary reliability. In Daubert, the Court is careful to make it clear that its discussion centered upon scientific rather than “technical or other specialized 16 knowledge.” However, a change in the adjective modifying knowledge does not change the central concern of reliability—that such knowledge (scientific, technical or specialized other) be capable of acceptance as truth on good grounds. It also seems clear that the Daubert factors showing scientific reliability—testability, peer review, error rate, controlling standards, and general acceptance—might prove useful individually, collectively, or in some combination with other factors in determining the reliability of technical or other 17 specialized knowledge. Always, the point of the inquiry is whether the knowledge in question is capable of acceptance as truth on good grounds. The district court in Joiner found that the opinions of plaintiff’s 18 experts were not based on reliable scientific knowledge. In the court’s view (...truncated)