The forensic footprint: Elemental and microbial evidence in relocated remains

Abstract

Here, we investigate the microbial and elemental signatures left behind at the sites of relocated remains, providing insights into postmortem processes that can assist forensic investigations of clandestine burials and relocated remains. We allowed two 90.7 kg (200lbs) clothed porcine models to decompose in open, varied environments in Arizona for a period of 25 days prior to the removal of the remains to secondary burial locations. After a period of 9 months, we collected soil samples from both the primary and secondary sites, as well as from control sites nearby. Our findings support the prevailing suggestion that microbial communities associated with decomposing remains exhibit distinct signatures, here dominated by Gammaproteobacteria and Clostridium, and demonstrate for the first time that these signatures remain detectable at a primary site for an extended period after a short decomposition period and relocation of remains to a secondary site. Additionally, elemental analyses identified significant differences in soil composition, particularly in macronutrients such as phosphorus and sulfur, between control and both primary and secondary deposition sites. These findings suggest that the traces left behind by decomposing remains can serve as forensic markers for an extended period after relocation. Our results highlight the potential of combining microbial and elemental analyses to enhance the understanding of decomposition and inform investigative strategies in forensic contexts. This research underscores the importance of microbial signatures in forensic science and calls for further exploration of their broader applicability in various burial environments.