Review of Estimation Models for Post Mortem Interval using Total Body Score and Accumulated Degree Days for Different Geographical Regions

Abstract

Post mortem interval (PMI) is the period since death of human or animal remains upon discovery. The study of decomposition of remains in forensic sciences has grown tremendously in recent years, hence, a good number of studies have provided taphonomic data on the prediction of PMI of decomposing cadaver remains using variables such as accumulated degree days (ADDs) and total body score (TBS). Mathematically, ADDs is the summations of mean daily ambient temperatures from the possible time of death to date of discovery of remains. Total body score is a quantitative variable used to evaluate whole body qualitative changes in the decomposition of such remains. Quantitative methods have been shown to provide a more objective and standardized assessment of decomposition. However, the question of a universal PMI model has been a difficult one to answer because of environmental variations within and between various regions in the world such as temperature, humidity, and presence of scavengers. These variations make it difficult to establish precise timelines for decomposition stages based solely on qualitative assessments. Therefore, the purpose of this article is to quantitatively review the impact of accumulated degree days and total body score from decomposition processes on the estimation of PMI and an attempt will be made to provide PMI models from various researches around the world.