Timing: the Achilles heel of forensic pathology
Forensic Sci Med Pathol
Timing: the Achilles heel of forensic pathology
Roger W. Byard 0 1
0 Discipline of Anatomy and Pathology, School of Medicine, The University of Adelaide, Level 3 Medical School North Building , Frome Road, Adelaide 5005 , Australia
1 & Roger W. Byard
''Time is an illusion''
A frequent scenario in the courtroom involves a
persistent lawyer trying to lock a pathologist into a particular
time frame for a finding, event, or injury. In cases of
trauma, a common gambit involves a question as to
whether the described injuries were recent or old. These terms
are then asked to be defined and specific time frames are
advanced: ‘‘if you assert that the injuries were recent, could
that be 3 h?’’ If that is agreed to, then the cascade of follow
up questions often includes ‘‘well would you be able to
exclude them being 2.5 h old?’’, ‘‘or perhaps 2 h?’’, ‘‘or
even 1.45 h of age?’’, ‘‘is it even possible that the injuries
were only an hour old?’’, and so on. Those with less
experience in court may attempt to assist by being as
‘precise’ as possible in their answers to the questions which
are designed to prove or disprove the possibility of a
suspect being present at the time of a crime. This may result in
the expert being boxed into an artificial time frame
resulting in a concluding statement by the interrogating
lawyer along these lines: ‘‘as the accused was the only
individual present with the victim within the time frame
advanced by the examining pathologist then he/she must
have been responsible for the assault.’’
The reality is that biological processes are a continuum
and cannot be compartmentalized into precisely defined
time periods. This, then, is our ‘‘Achilles heel’’ which has
been defined (perhaps optimistically in some cases) as an
area of weakness despite overall strength; i.e., while we
usually have an excellent understanding of the general
principles and sequence of responses to injury, disease, and
pathological processes, it may simply not be possible to use
this to determine the exact timing for an individual case.
There are a myriad of reasons for this that include
idiosyncratic responses to injury and to pathophysiological
processes, the wide variation that exists in the types,
force/patterns of trauma, and significant differences that
occur in ante and post-mortem environments. It is clearly
illogical to assume that every injury and every process in
every person would follow identical time lines.
The timing of death is a classic example of how well a
process is understood and yet how poorly this can be
applied to specific cases. It has been recognized for
centuries that after death a series of stereotypical changes occur
that commence with cooling of the body (algor mortis),
stiffening of muscle groups (rigor mortis), and pooling of
blood in dependent parts (livor mortis) [
]. This is
followed by autolysis, putrefaction, and skeletonization,
sometimes with additional processes such as adipocere
]. Despite apparently precise scientific methods
to date post-mortem interval being developed that are based
on comparisons between core body and environmental
], it is well recognized that these are
frequently confounded by variation in body size and fat
content, the wetness of the body, the amount of clothing or
bedding, changes in the ambient temperature, disturbance of
the scene, and the presence of strong air currents/winds.
Post-mortem changes such as putrefaction and
skeletonization also cannot be relied upon to indicate consistent
time frames as they may be greatly accelerated by
environmental factors such as high ambient temperatures,
or by endogenous infectious or metabolic conditions [
Another post-mortem change that may be encountered is
the development of adipocere or corpse wax in bodies
exposed to certain environmental conditions when
triglycerides have hydrolyzed into free fatty acids and
]. Although it is thought to take months or years
to develop, it may occasionally occur within days of death,
again emphasizing the marked temporal variability that
characterizes biological processes [
In some jurisdictions the contemporaneous deaths of
two elderly spouses in a vehicle accident may raise the
question as to who died first. This, of course, may have
great significance in terms of inheritance if there are family
members from previous marriages who may be only
considered in the will of one of the decedents and not the other.
However, reports giving estimates on the timing of the
deaths based on relative ages and injuries are often only
guesswork with no scientific basis, particularly if the ages
of the decedents and the types of injuries are comparable.
Similar difficulties may occur in attempting to date vital
processes that have occurred before death. The aging of
bruises is an excellent example of problems that may occur
in attempting to impose a rigid temporal framework on a
quite fluid biological phenomenon. It is well recognized
that the time taken for a bruise to appear may be markedly
affected by the location of the injury and the depth of the
bleeding. Charts giving precise timing for color changes
listed in textbooks have been shown to be contradictory
and non-reproducible and the rates and nature of
histological changes can vary greatly depending on the site of
tissue sampling [
The time taken for the stomach to empty has been used
on occasion in court in an attempt to give some idea of the
time between a last meal and death [
]. However, for a
number of decades it has been recognized that individual
variability makes this a very imprecise indicator. In fact,
Marshall nearly half a century ago commented that ‘‘the
rate of emptying of the stomach is so variable that it cannot
be used to give any certain indication of the time that has
elapsed between the last meal and death’’ [
problem is that the rate of gastric emptying may be significantly
affected by the nature of the ingested food, stress, drugs,
disease states, and infections [
]. Thus, if food is found
within the stomach at autopsy by a pathologist, the most
reasonable conclusion is that the person has died sometime
Unfortunately these concepts are often difficult to
translate for the courts. For example, despite an expert
giving quite a detailed dissertation explaining why the
dating of bruises is at best imprecise, the next question is
often one asking for the precise age of a specific lesion.
This is partly due to a failure to understand the gray areas
of pathology that in previous decades may have been
underemphasized. Also it may not suit a particular legal
argument to have an open ended time period. Whatever the
reasons for this medicolegal mismatch, it is important that
pathologists are very aware of the considerable limitations
that the autopsy examination of devitalized organs may
have in terms of shedding light on the exact timing of
particular ante and post-mortem events/processes.
Determining whether time itself is an illusion or not is a little
beyond the scope of this editorial, however, the belief that
pathological analyses can always provide an accurate
chronology for an autopsy finding probably is.
1. Casper JL . A Handbook of the practice of forensic medicine based upon personal experience . Vol 1 . Thanatological Division . Ch 2 . London: The New Sydenham Society; 1861 . p. 14 - 55 .
2. Madea B . Methods for determining time of death . Forensic Sci Med Pathol . 2016 . doi: 10 .1007/s12024-016-9776-y.
3. Madea B . Estimation of the time since death . 3rd ed. Boca Raton: CRC Press; 2016 .
4. Prahlow J , Byard RW . An atlas of forensic pathology . New York: Springer; 2012 .
5. Henssge C , Madea B . Estimation of the time since death in the early post-mortem period . Forensic Sci Int . 2004 ; 144 : 167 - 75 .
6. Zhou C , Byard RW . Factors and processes causing accelerated decomposition in human cadavers. An overview . J Forensic Leg Med . 2011 ; 18 : 6 - 9 .
7. Byard RW . The complex spectrum of forensic issues arising from obesity . Forensic Sci Med Pathol . 2012 ; 8 : 402 - 13 .
8. Byard RW . Adipocere-the fat of graveyards . Am J Forensic Med Pathol . 2016 . doi: 10 .1097/PAF.0000000000000251.
9. Thali MJ , Lux B , Lo¨sch S , Ro¨sing FW, Hu¨rliman J , Feer P , et al. ''Brienzi'' -the blue vivianite man from Switzerland: time since death estimation of an adipocere body . Forensic Sci Int . 2011 ; 211 : 34 - 40 .
10. Kumar TSM , Monteiro FN , Bhagavath P , Bakkannavar SM . Early adipocere formation: a case report and review of literature . J Forensic Leg Med . 2009 ; 16 : 475 - 7 .
11. Byard RW , Wick R , Gilbert JD , Donald T. Histologic dating of bruises in moribund infants and young children . Forensic Sci Med Pathol . 2008 ; 4 : 187 - 92 .
12. Byard RW , Langlois NEI . Bruises-is it a case of ''the more we know the less we understand''? Forensic Sci Med Pathol . 2015 ; 11 : 479 - 81 .
13. Horowitz M , Pounder DJ . Gastric emptying-forensic implications of current concepts . Med Sci Law . 1985 ; 25 : 201 - 14 .
14. Marshall TK . Changes after death . In: Camps F, Robinson AE , Lucas BGB , editors. Gradwohl's Legal Medicine. 2nd ed. Bristol: John Wright & Sons Ltd; 1968 . p. 105 .