How does mass loss compare with total body score when assessing decomposition of human and pig cadavers?

Abstract

Providing accurate and reliable measures of decomposition is paramount for forensic research where decomposition progress is used to estimate time of death. Mass loss is routinely used as a direct measure of biomass decomposition in ecological studies, yet few studies have analysed mass loss in a forensic context on human cadavers to determine its usefulness for modelling the decomposition process. Mass loss was examined in decomposing human and pig cadavers, and compared with other common decomposition metrics, such as total body score (TBS). One summer and one winter field decomposition experiment was conducted using human and pig cadavers, as pigs are often used as proxies for human cadavers in forensic research. The two measures of decomposition revealed two contrasting patterns of decomposition on pigs and humans, particularly in winter where TBS stabilised at similar values, but mass loss differed greatly. Mass loss was found to be faster in pigs than humans during early decomposition. Pigs lost 75% of their mass in winter, while humans lost less than 50%; however, in summer, both lost around 80% of their mass. TBS displayed similar patterns in both experiments, with TBS increasing more rapidly in pigs compared with humans but both eventually reaching similar TBS values in late decomposition. Measuring mass loss can provide additional information about decomposition progress that is missed if using TBS only. Key differences in decomposition progress between cadaver types were also observed, suggesting caution when extrapolating data from pigs to humans for forensic research and decomposition modelling.

Soil microbial communities and biogeochemistry during human decomposition differs between seasons: evidence from year-long trials

“…TBS plotted as a function of environmental ADD values yielded sigmoidal patterns in agreement with both animal [2,19,64,66,67] and human studies [2,[68][69][70]. We also noted that the relationship between TBS and ADD varied between the two trials, supporting reports from other comparative seasonal studies [2,42,71]. This suggests that TBS may not be as predictable based on ADD as originally intended [50] and that seasonality should be taken into consideration when using thermal time to predict decomposition.…”

Influence of carcass mass on decomposition rate: A medico‐legal entomology perspective

“…In addition, the remaining mass (%) compared to TBS surf for small and large carcasses decreased at an almost constant rate until the end of decomposition. Understanding this correlation can offer the possibility of estimating the remaining mass (%) variable for other researchers who may be unable to directly measure this variable in experiments or at crime scenes (Dawson et al 2022).…”

“…Understanding this correlation can offer the possibility of estimating the remaining mass (%) variable for other researchers who may be unable to directly measure this variable in experiments or at crime scenes (Dawson et al . 2022).…”

Refining decomposition stage estimation: A study of seasonal insect composition and carcass weight change

“…2016; Dawson et al . 2022). These methods, however, are influenced by changing environmental conditions, introducing subjectivity and reducing reliability.…”

“…Historically, the total body score (TBS) and insect succession have been primary estimators for the minimum post-mortem interval (PMI min ) (Matuszewski et al 2008;Moffatt et al 2016;Dawson et al 2022). These methods, however, are influenced by changing environmental conditions, introducing subjectivity and reducing reliability.…”