The post-mortem interval (PMI) is the time that has elapsed since an individual's
death.[1] When the time of death is not known, the interval may be estimated, and so an approximate time of death established. Postmortem interval estimations can range from hours, to days or even years depending on the type of evidence present.[2] There are standard medical and scientific techniques supporting such an estimation.[3]
Conditions at the scene of death affect the estimation of time of death. To algor mortis, livor mortis and rigor mortis, together with consideration of stomach contents, there needs to be some observation of environmental conditions at the death scene to accurately measure the PMI (Fig. 1).[4] Factors that can effect the rate of human decomposition are concerned with the particular environment a body has been recovered from.[2] Bodies can be found anywhere from terrestrial to aquatic environments, each possessing their own variables that can alter interval estimations.[5] Along with common factors of temperature, humidity and element exposure,
body habitus and clothing are an example of a component that can affect the rate of cooling of the body, and so its rate of decomposition.[5][6] A very approximate rule of thumb for estimating the postmortem interval is as follows:[7]
Warm and flaccid: less than 3 hours
Warm and stiff: 3 to 8 hours
Cold and stiff: 8 to 36 hours
Cold and flaccid: More than 36 hours.
Due to significant environmental variations between regions, universal formulas would be ill-suited for this topic in
forensic science.[8]
^
abJason H. Byrd; James L. Castner, eds. (2009). Forensic entomology: the utility of arthropods in legal investigations (2nd ed.). Boca Raton: Taylor & Francis.
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abcSimmons, Tal (2017-02-10), "Post-Mortem Interval Estimation: an Overview of Techniques", Taphonomy of Human Remains: Forensic Analysis of the Dead and the Depositional Environment, Chichester, UK: John Wiley & Sons, Ltd, pp. 134–142,
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10.1002/9781118953358.ch10,
ISBN9781118953358
^Senior, T (2018). Forensic ecogenomics : the application of microbial ecology analyses in forensic contexts. London, United Kingdom San Diego, CA: Academic Press.
ISBN978-0-12-809360-3.
OCLC1023028365.
^Lin, X; Yin, YS; Ji, Q (2011). "Progress on DNA Quantification in Estimation of Postmortem Interval". Fa Yi Xue Za Zhi. 27 (1): 47–9, 53.
PMID21542228.
^Huang, P; Tuo, Y; Wang, ZY (2010). "Review on Estimation of Postmortem Interval Using FTIR Spectroscopy". Fa Yi Xue Za Zhi. 26 (3): 198–201.
PMID20707280.
^Davla, M; Moore, TR; Kalacska, M; LeBlanc, G; Costopoulos, A (2015). "Nitrous Oxide, Methane and Carbon Dioxide Dynamics from Experimental Pig Graves". Forensic Science International. 247: 41–47.
doi:
10.1016/j.forsciint.2014.12.002.
PMID25544693.
^Senos Matias, MJ (2004). "An Investigation into the Use of Geophysical Methods in the Study of Aquifer Contamination by Graveyards". Near Surface Geophysics. 2 (3): 131–136.
doi:
10.3997/1873-0604.2004010.
^Van Belle, LE; Carter, DO; Forbes, SL (2009). "Measurement of Ninhydrin Reactive Nitrogen Influx into Gravesoil during Aboveground and Belowground Carcass (Sus domesticus) Decomposition". Forensic Science International. 193 (1–3): 37–41.
doi:
10.1016/j.forsciint.2009.08.016.
PMID19773138.