Evaluation of porcine decomposition and total body score (TBS) in a central European temperate forest

The total body score (TBS) is a visual scoring method to scale the succession of decomposition
stages. It compares decomposition between cadavers, to connect it
with external taphonomic factors and estimate the post-mortem
interval. To study
decomposition in various climatic environments, pigs are often used as human proxies.
Currently, there is one TBS system by Keough et al. (J Forensic Sci. 2017;62:986)
for surface-deposited
domestic pigs, coming from South Africa. Our study aims to
evaluate this method and analyze porcine decomposition in Central Europe to inform
forensic research and casework. We conducted an experiment studying six 50 kg pig
carcasses in a temperate Swiss forest. Three observers documented decomposition
patterns and rated the decomposition stages from photographs based on the porcine
TBS model by Keough et al. (J Forensic Sci. 2017;62:986). We documented discrepancies
between the carcass decomposition of our specimens and those in the
South African study, especially related to the high insect activity in our experiment.
Furthermore, we noted factors complicating TBS scoring, including rainfall and scavengers.
The agreement between TBS observers from photographs was in the highest
agreement category apart from one “substantial agreement” category. Our study is
the first in Europe to systematically test the Keough et al. (J Forensic Sci. 2017;62:986)
method. The results evidence that regional adaptations are required to be applicable
for other environments. We present a modified approach based on experimental observations
in a Swiss temperate forest. The identification of regional decomposition
patterns and drivers will inform future taphonomy research as well as forensic casework
in comparable contexts in Central Europe.