Forensic estimation of time since death: a comparative study of polynomial regression and modified Newton’s models

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November, 2015
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Empirical studies have been made into the determination of Time Since Death (ATSD).This study attempts to briefly review most of the methods used to estimate TSD and concentrate on the development of a Polynomial Regression Model (PRM) and a Modified Newton’s Model (MNM) that accurately predicts TSD and chose the most consistent, efficient and accurate estimator of TSD between the two. Such a model, when accurately developed, will add to the security services scientific ways of predicting TSD, as well as, help in civil and criminal cases. The study found out that the PRM best predicts TSD with an R2 of 99:87% given the two secondary data obtained from the Journal of the Indian Academy of Forensic Medicine 2005 volume 27(3) : 170 - 176 and the Acta Morphologica 2006, volume 3(3) : 52 - 53 (Macedonia Association of Anatomists and Morphologists). The MAPE, MAD and SSE of the two models were also statistically tested and compared to that of the Actual Time Since Death (ATSD).The MNM relied on the use of an iterative method, to determine the number of times, time (denoted t in hours) changes over time for Rectal Temperature (RT) to coincide with the developed model of differential equation .The calculation embodied several parameters /conditions that affect the cooling rate of dead bodies.
A thesis submitted to the Department of Mathematics, Kwame Nkrumah University of Science and Technology in partial fulfillment of the requirement for the Degree of Master of Science in Industrial Mathematics, 2015