Improving Estimates of the Postmortem Interval with Metagenomics and Metabolomics

As submitted by the proposer: The use of molecular data has radically transformed forensic science by providing the ability to identify individuals, unknown materials, and metabolic processes. These molecular approaches have had a significant impact on medicolegal death investigation because they have led to the identification of people associated with death as well as the factors contributing to and causing death. Recently postmortem microbiome studies have shown that amplicon based next-generation sequencing data can be used to estimate the postmortem interval and locate clandestine graves. These data have significant potential for forensic science, but incorporating metagenomic and metabolomic data may increase their power even further. These three datasets will then allow us to determine (1) what microbes are present, (2) what the microbes are doing, and (3) what chemical compounds they are generating, respectively. This will ultimately generate a three-pronged approach to investigating postmortem microbial ecology and improve our understanding of the accuracy, reliability, and measurement validity of postmortem microbiome data. The proposed project will achieve this goal by incorporating shotgun metagenomic data and metabolomics data into the workflow of a currently funded project (NIJ-2015-DN-BX-K016) that utilizes thousands of samples to investigate the decomposition of human corpses in three contrasting environments: Colorado, Tennessee, Texas. Furthermore, the design of the proposed project will allow for the achievement of both fundamental and applied research goals: The proposed datasets will not only be applied to a forensic context but they also represent one of the first studies to investigate these components in disparate terrestrial ecosystems. Thus, our proposed project represents an innovative research opportunity in forensic science research. Note: This project contains a research and/or development component, as defined in applicable law. ca/ncf