Thick quilt may severely impact the estimation of postmortem interval using forensic entomology-based methods -two case reports

Abstract

This paper introduces two indoor cases in China, characterized by bodies lying on a mattress, covered with thick quilts and wearing clothes. There were obvious deviation in the estimated minimum postmortem interval (PMI_min) of the corpses using entomological methods. Based on the forensic entomology evidence from the scene, the PMI_min estimated using temperature data from the nearest weather station was longer than the actual postmortem interval (PMI) based on the police investigation and the security camera footage. The most probable cause of the errors in PMI_min estimation was the hindrance in heat dissipation since the corpses were covered with thick quilts while lying on the mattress. Therefore, the heat generated by the decomposition process and larval activity was hard to lose, resulting in the rapid development of insects. These case reports emphasize the importance of temperature collection in forensic entomological investigations. Our findings call for standardized temperature acquisition procedures, including which temperature measurements (body, microenvironment or ambient temperature) should be used in forensic entomological investigations when handling similar cases.

Keywords: Case; Forensic entomology; Postmortem interval; Quilt; Scene temperature.