Forensic Analysis: Postmortem Interval and Time of Death Determination

This report provides an analysis of the postmortem interval (PMI), a critical aspect of forensic pathology used to determine the time of death. It critiques the presentation of PMI in a case, highlighting flaws such as providing a precise time instead of a range. The report discusses factors influencing PMI, specifically focusing on Algor Mortis, the cooling of the body after death, and the various elements that can affect this process, including ambient temperature, body composition, clothing, and environmental conditions. The report also introduces the Glaister Equation, a tool used to estimate the time of death based on body temperature. The document references several studies and provides a comprehensive overview of the complexities and considerations involved in determining the postmortem interval.

Running head: POSTRMORTEM INTERVAL 1
Postmortem Interval
Name
Institution

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POSTERMORTEN INTERVAL
Introduction
One of the most vital pieces of evidence in a case that involves a deceased body
identification is to answer what seems to be a direct question - “when did the deceased die?” A
detective, more beloved by the “romantic crime” genre is probably to look at the wristwatch of
the deceased and declare the time of death to that shown on now fractured and distorted face.
The most credible, reliable and valid response to this seemed straight-forward question is
probably to be obtained from impartial or unbiased eyewitness to the event.
a) A flaw in the presentation
In identifying the flaw, the main focus is to identify how long the deceased has been
lying since death. The pathologist was wrong by giving accurate time (twelve hours-twenty
minutes) than the recommended practice of providing a range of times within which the death is
likely to have taken place. In this case, the pathologist errored by specifically stating that the
body had been dead for twelve hours and twenty minutes. The longer the post-mortem interval,
the broader the range will be. Such an accurate estimate, unfortunately, is only allowed to come
from the least experienced medical witness who tends to offer the most exact estimate. Indeed,
another flaw in the presentation is that the pathologist gave a fraction of an hour (1hr, 20
minutes) rather than the recommended practice of giving a whole hour. Thus such a presentation
attracts a considerable skepticism from the word go.
b) Factors leading to forensic pathologist modifying PMI
Algor Mortis is the second phase of decomposition which translates to ‘coldness” (algor)
“of death” (mortis). It is sometimes dubbed “death chill” and marked by a stable drop in
temperature of the body. It continues till the corpse hits “ambient temperature,” matches the

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surroundings’ temperature. It usually ensues in 1 hour following death. Many factors have
substantial influence on this stage of decomposition. Correct time of death determination via
body temperature can be challenging because of fluctuation or stability of ambient temperature,
thermal conductivity of surface the corpse is place and temperature plateau-a highly variable
time period whereby the body doesn’t cool. The cooling rate could surged where the deceased is
malnourished or thin or if the body is exposed to low temperatures and or windy environment.
Conversely, where the deceased was running a fever (febrile), under the influence, obese, or left
in a warm environment, cooling rate shall decrease. Clothing also play a key role in escalating or
slowing down Algor Mortis. The deceased shall cool faster if huge amounts of skin are exposed
or if wearing wet clothing. Dry, layered, and heavy clothing keeps the deceased body warm for
an extended period of time following death. After the body has begun true decomposition, the
temperature shall increase again thereby making Algor Mortis increasingly helpful in the
determination of correct time pf death within the initial twenty-four hours. Temperature readings
are obtainable from deceased’s rectum or via the insertion of a meat thermometer under
deceased’s ribcage on right side and into liver. Glaister Equation (GE) is used by investigators in
estimating time of death. Whereas temperature fluctuation can vary anywhere between 1.0
degrees Fahrenheit (F) decline in temperature an hour to a 12.0 degrees F decline an hour, the
average remains 1.50 degrees F plunge an hour, every hour following death. The GE uses 98.40
degrees F (av. body temperature) less rectal (or internal) temperature in degrees F, divided by
1.50 degrees F, to equate death time.

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References
Adair, T. (2012). Aspects Influencing the Entomological Postmortem Interval in Crime Scene
Reconstruction. J Assoc Crime Scene Reconstr, 18(3).
Al-Alousi, L. M., Anderson, R. A., Worster, D. M., & Land, D. V. (2002). Factors influencing
the precision of estimating the postmortem interval using the triple-exponential formulae
(tef): Part ii. a study of the effect of body temperature at the moment of death on the
postmortem brain, liver and rectal cooling in 117 forensic cases. Forensic science
international, 125(2), 231-236.
Ito, T., Tamiya, N., Takahashi, H., Yamazaki, K., Yamamoto, H., Sakano, S. ... & Miyaishi, S.
(2012). Factors that prolong the ‘postmortem interval until finding’ (PMI-f) among
community-dwelling elderly individuals in Japan: analysis of registration data. BMJ
open, 2(5), e001280.