Validation Study of the Utility of Using Total Body Score and Accumulated Degree Days to Determine the Post-Mortem Interval of Human Remains from Three Human Decomposition Research Facilities

As submitted by the proposer:
To be widely employed in forensic science, the method developed by Megyesi and colleagues (2005) for estimating the postmortem interval using accumulated degree dates (ADD) and total body score (TBS) needs to be tested in multiple climatic regions and equations likely modified for each climatic zone (Megyesi et al. 2005). Therefore, our study applies the TBS/ADD method developed by Megyesi and colleagues (2005) in three human decomposition facilities, located in different ecoregions. The three research facilities are the Anthropology Research Facility at the University of Tennessee, Knoxville; a temperate environment, the Forensic Anthropology Center at Texas State University, San Marcos; a subtropical, sub-humid environment, and the Southeast Texas Applied Forensic Science Facility, Sam Houston State University, Huntsville; a subtropical, humid environment. A total of 105 donated human cadavers will be studied. Four subjects will be placed four times per year at each research facility; two subjects in shade and two in a sun environment. Assessment of TBS will be done on a daily basis and ADD will be calculated from local temperature data. Megyesi et al.'s equation will be used to calculate PMI for each body and compared to the known PMI. Each co-PI will also incorporate locally specific variables into the equation to develop a region-specific formula. The final placement of bodies will be used to test the region-specific formulae developed from the seven previous placements. Our results will be useful for forensic anthropologists, medical examiners, and medicolegal investigators that deal with human decomposition cases. The proposed study is necessary due to 1) the absense of established human decomposition data for two Texas regions, 2) the need to develop and test the TBS method utilizing ADD in these diverse ecoregions, 3) the need to develop standardized data collection methods for human decomposition studies, and 4) the need for large sample sizes for statistical robustness. With the accumulation of data, we will be able to clearly establish deviations from or similarities to each environment.

We will be able to test the TBS using ADD method designed by Megyesi et al. (2005) in experimental field studies, not assessed from case photos. This study will initiate the first steps needed in standardizing the process by which researchers conduct human decomposition research (i.e. collect data). It will also be a useful tool if forensic anthropologists and the medicolegal and criminal justice community, who consult on taphonomic cases, can easily access a database that contains a model for assessing the PMI along with images and instructions on its use.

Interim and final reports will be submitted to NIJ as required. Final dissemination will include presentation to the relevant scientific community at professional meetings, publication in peer-reviewed journals, and training opportunities via workshops, symposiums and/or webinars for medicolegal investigators and law officers.
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