Biological Clocks of Death: Microbiology in the Estimation of the Postmortem Interval in Forensic Sciences

Abstract

The determination of the postmortem interval (PMI) is a critical component of criminal investigations and is traditionally based on cadaveric phenomena or insect succession. Nevertheless, accurately estimating the PMI continues to pose significant challenges for forensic practitioners, necessitating the development of more precise methodologies. Microorganisms represent an ideal form of physical evidence due to their extensive diversity and ubiquitous presence across various environments. The human body hosts trillions of microbial cells that constitute the microbiome, which interacts continuously with host cells throughout life. Following death and the initiation of decomposition, a series of physiological and biochemical changes occur, delineating distinct stages of decomposition. The cadaver serves as a rich nutrient source for both resident and environmental microorganisms, facilitating successive alterations in microbial communities over time. Microbial succession across different anatomical regions has demonstrated considerable potential as a forensic tool for estimating the time since death. This study presents a comprehensive overview of the diverse sources of microorganisms within the human body and explores the stages of decomposition in relation to microbial community succession through an integrative analysis of literature published over the past fifteen years (2010–2025). The objective is to underscore the applicability of microbiological approaches in PMI estimation within forensic contexts. The findings suggest that microorganisms may serve as supplementary indicators in PMI determination; however, current research remains insufficient to fully validate their forensic utility.

Keywords

Microbiologia
Forense
Mudanças Depois da Morte
DNA barcoding
forensic microbiology
microbiome
post mortem changes

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