Postmortem interval estimation through skeletal muscle protein degradation: a comprehensive review

Postmortem interval (PMI) estimation is a pivotal challenge in forensic science, and skeletal muscle protein degradation has emerged as a promising biochemical tool. In this review, we conducted a comprehensive literature search of PubMed for studies published between 2014 and 2024 using keywords related to PMI estimation and protein/proteomics. Of the 287 results retrieved, 81 were available as free full-text articles, and 17 met the inclusion criteria focusing on skeletal muscle protein. The most used techniques were Western blotting, followed by mass spectrometry and immunohistochemistry. Frequently studied proteins included eEF1A2, desmin, GAPDH, α-actinin, vinculin, α-tubulin, and tropomyosin. Although protein degradation in muscle tissue shows significant potential for PMI estimation, relying on a single protein or a small group of proteins is insufficient due to variability introduced by environmental, individual, and species-specific factors. The study highlights the need for long-term, semi-controlled studies using human tissue, as well as further investigation of new candidate biomarkers and the stability of established markers across diverse PMI ranges and conditions. Comparative studies between animal and human data are vital for understanding species differences and ensuring reliable extrapolation. Moving forward, interdisciplinary and methodologically standardized approaches will be critical for integrating protein-based findings into routine forensic practice and achieving a robust, multifactorial method for PMI estimation.