The Impact of Postmortem Interval on the Reliability of Forensic Autopsy Evidence in Murder Cases: A Comprehensive Analysis in Nairobi, Kenya

Abstract

Background. Postmortem interval (PMI) significantly affects the accuracy and interpretation of forensic autopsy evidence in murder cases. In Nairobi, Kenya, where resources and infrastructure may be limited, the relationship between PMI and evidence reliability is critical to effective investigation and prosecution.

Objective. To identify the specific challenges associated with postmortem interval and to assess its impact on the reliability of autopsy findings in murder cases in Nairobi.

Methods. A retrospective analysis of 150 murder cases in Nairobi between 2018 and 2023 stratified cases by PMI (early <24 hours, intermediate 24–72 hours, late >72 hours). Autopsy reports were reviewed to assess the reliability of evidence on cause of death, manner of death, and identification, and statistical analyses examined the correlation between PMI and evidence reliability.

Results. As PMI increased, the reliability of forensic evidence decreased significantly. Early PMI cases showed the highest reliability for cause of death, manner of death, and identification, whereas late PMI cases presented difficulties in interpretation due to decomposition, scavenging, and environmental factors, producing uncertainty about cause and manner of death, particularly where blunt force trauma or asphyxia was involved.

Conclusion. PMI has a critical impact on the reliability of forensic autopsy evidence in murder cases in Nairobi. Early examination is essential for accurate and reliable evidence, especially in resource-limited settings, and standardized protocols, improved infrastructure, and ongoing training for forensic pathologists are needed to mitigate the challenges associated with PMI.