Post Mortem Paper

Chemical Changes Postmortem and
Their Effects on the Determination of Postmortem Interval
Emily Morello
University of New Haven
FORS-2216-03-F15
Professor Peter Valentin
30 November 2015

Post mortem interval (PMI) is a commonly used term in the Forensic Science field meaning the time since death, or the time elapsed between death and the time of postmortem examination. Due to its assistance in suspect investigations, post mortem interval is very important in criminal cases. The more time elapsed, the larger the limits of probability. Therefore, the need for the findings of immediate chemical changes in the human body is inevitable. HodaFouad Abdel Salam, Eman Ahmed Shaat, Manal Hassan Abdel Aziz, Abeer Abdel MoneimSheta, and
The State v. Dreher specifically shows its liability as a reliable, evidentiary statement in today’s court cases. State v. Dreher, (1997), was an appellate division court case within the superior court of New Jersey where defendant John W. Dreher challenged the judgment of the State Court of New Jersey that convicted him of purposeful and knowing murder of his wife. In this case, the medical examiner considered a variety of different factors, with respect to time of death, including the concentration of vitreous potassium following the death of the defendant’s wife. Even though not an exact science, State v. Dreher (1997) stated that “the victim's potassium concentration level was 7.3 milliequivalents per liter” which led to the estimation that the victim had died ten hours earlier, give or take four hours (1997, p. 34). As noted by the medical examiner, “since her vitreous fluid was drawn at 5:40 p.m., she died sometime between 3:40 a.m. and 11:40 a.m. but probably closer to 7:40 a.m.” carefully stating only a range rather than a precise time (1997, p.
60). In the end however, the court affirmed the defendant's conviction for murder in the first degree of his wife by overruling his claimed errors that the state had unfair prejudice against the defendant. His claims were overruled due to the medical examiner’s use of a widely accepted and distributed graph amongst all United States medical examiners by the Department of Justice Law Enforcement Assistance Administration. State v. Dreher (1997) proved that the medical examiner arrived at this estimate using the vertical coordinates, which represent the known potassium levels for more than one hundred people that died, and the horizontal coordinates, that represent the number of hours since death. This case therefore, historically revolutionized the use of this methodology of retrieving an appropriate time interval since