Discovery of biomarker signatures to accurately estimate time since death

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Every year, between 70,000 to 80,000 people go missing in Canada. For those who are not found within seven days, the likelihood of discovery is significantly decreased. When human remains are discovered, the greatest challenge is to determine time since death (TSD) to assist with victim identification. Current methods for estimating TSD are either limited to days (forensic pathology), or years (forensic anthropology, odontology), or are not useful year-round in cold climates like Canada (forensic entomology). Prior attempts to identify TSD methods have focused on a single marker which do not meet the accuracy and precision required for death investigations. We propose that an interdisciplinary approach involving the addition of biomarker discovery (NSERC) will significantly improve TSD estimates when incorporated with forensic pathology (CIHR), anthropology (SSHRC) and odontology (CIHR) methods. Our objective is to fill this gap by discovering novel biomarker signatures linked to time in degrading soft and hard tissues. We will achieve this by investigating a suite of metabolomic, isotopic and genomic biomarkers. Research will be conducted at the facility for Research in Experimental and Social Thanatology (REST); the only facility in Canada where TSD can be studied through human body donation. REST blends medical, natural and social science research ensuring our ability to concomitantly assess pathological (vitreous humor), anthropological (bone chemistry), and odontological (dental pulp) changes, while discovering and quantifying new biomarkers (e.g. 15N, methylated DNA, fatty acids) in soft and hard tissues. The estimation of TSD is particularly important in investigations where a criminal event has occurred, such as homicide. Current data in Canada suggests homicide rates are seven times higher in people with Indigenous identity; many of these go unsolved as evidenced by the National Inquiry into Missing and Murdered Indigenous Women and Girls. An enhanced estimation of TSD can significantly increase the likelihood of identifying marginalized victims, or any victim of violence, permitting the return of their remains to their grieving families. Our research will therefore have significant societal impact by helping to bring missing persons home. It will provide a more rapid resolution to medico-legal death investigations and the prosecution of offenders, thus increasing the safety and security of the Canadian public.