A Universal Microbial Clock for Estimating the Postmortem Interval Metcalf Mouse exp

Establishing the time since death and locating clandestine graves are crucial goals in many forensic investigations, but can often be a challenge because our understanding of human decomposition is very limited. Thus, forensic science currently does not fully leverage decomposition processes as physical evidence. Microbial communities are ubiquitous, crucial for decomposition, and hold great potential as a forensic tool. We show that archaeal, bacterial and microbial eukaryotic communities can be used to estimate the postmortem interval in both a laboratory-based mouse model system as well as in a human model system in the field. Additionally, we demonstrate that bodies decomposing on soil modify the soil microbial community substantially, allowing detection of a decomposing body via the soil microbial community, with forensic implications in scenarios in which bodies are buried or have been moved. Together, these results suggest that microbial communities associated with decomposition hold great promise for forensic science.