Abstract
This pilot study uses redacted casework in Florida from forensic anthropologist Dr. Heather Walsh-Haney to compare two postmortem interval (PMI) estimation methods that use a
regression equation to calculate accumulated degree days (ADDs) from the total body score
(TBS). Megyesi, Nawrocki, and Haskell (2005) created the initial decomposition scoring system
to score changes that happen to different areas of the body after death, and the sum of the scores
is the TBS. The ADD was calculated with linear regression using their decomposition score for
accumulated temperature. Moffatt, Simmons, and Lynch-Aird (2016) found that the research had
shortcomings and took steps to improve it by developing a new equation. I hypothesized that
there would be differences in the ADD calculation and PMI estimations between the two
methods. Statistical analysis using International Business Machines (IBM) Corporation (2023)
Statistical Package for the Social Sciences (SPSS) for Windows, Version 29.0.1.0 showed that
there were differences in the ADD calculations and PMI estimations produced by Megyesi et al.
(2005) and Moffatt et al. (2016), as well as in the prediction intervals. As this is a pilot study, I
recommend future research examine if the Megyesi et al. (2005) and Moffatt et al. (2016)
methods can accurately predict the actual ADD and PMI when remains are recovered from
Florida from the surface though not burned, buried, or submerged. Future studies should also
examine if there is a difference between the weather station data closest to the scene of discovery
as well as from areas that match the microclimate of the scene; and if findings from other similar
studies can be generalized to Florida.