The use of generalized linear mixed models to investigate postmortem lipids in textiles

Human remains are oftentimes located with textile materials, making them a ubiquitous source of physical evidence. Human remains are also frequently discovered in outdoor environments, increasing the exposure to scavenging activity and soft-tissue decomposition. In such cases, postmortem interval (PMI) estimations can be challenging for investigators when attempting to use traditional methods for reconstructive purposes. Lipid analysis is an emerging area of research in forensic taphonomy, with recent works demonstrating success with the detection and monitoring of lipids over time. In this work, generalized linear mixed models (GLMMs) were utilized to perform rigorous statistical analyses on 30 lipid outcomes in combination with accumulated-degree-days (ADD). The results of this study were consistent with recent works, indicating oleic and palmitic acids to be the most suitable lipids in textiles to target for future use as soft-tissue biomarkers of human decomposition. Interspecies differences between humans and pigs were also addressed in this work.

Automated summary

Human remains often contain textile materials, making them a common source of evidence. The discovery of human remains in outdoor environments increases exposure to scavenging activity and decomposition. Traditional methods for estimating postmortem interval (PMI) can be challenging, but recent research has found success in using lipid analysis to detect and monitor changes over time. This study utilized generalized linear mixed models (GLMMs) to analyze 30 lipid outcomes in combination with accumulated-degree-days (ADD), and the results indicated oleic and palmitic acids as suitable biomarkers for future use in determining PMI. The study also addressed interspecies differences between humans and pigs.