This is the Final Summary Overview of a project whose goal was to simplify and standardize human cadaver decomposition observations to maximize agreement among observers and reduce bias.
Decomposition observations were standardized by the development of a list of easily identified traits that are recorded as present or absent. The development of the trait list relied on the trait lists of Megyesi et al. (2005) and observations from a proof-of-concept pilot study. This study addressed the deficiencies of the Megyesi method of total body score (TBS) by using empirical longitudinal data from cadaver donors with known postmortem interval (PMI) rather than photographs that had minimal temporal or contextual control. By placing multiple human donors at the same time in the same environment, direct observation of variation within and among individuals provides a more realistic and nuanced error rate. The inclusion of a discrete list for the independent scoring of 16 regions of the body minimizes scoring bias inherent in the bilateral asymmetry of normal decomposition processes. A compilation of a list of discrete traits (presence/absence) that can be scored in the field is then converted to an associated weighted score that reduces bias and increases observer agreement. The addition of a scavenging observation adds the ability to document rapid tissue loss due to animal activity. The inclusion of geographic-information-system (GIS) techniques enables both the visualization and quantification of decomposition patterns over time with the use of heat maps and hot-spot analysis. The project subjects were from the Forensic Anthropology Center's body donation program based on a set of criteria. Data analysis is described in this report. The preliminary results of this project can significantly impact medicolegal investigations by providing empirically grounded and realistic estimates of time since death and a more reliable method for collecting decomposition field data. 2 tables, 2 figures, and 6 references