The Role of DNA Degradation in the Estimation of Post-Mortem Interval: A Systematic Review of the Current Literature

The determination of the post-mortal interval (PMI) is an extremely discussed topic in the literature and of deep forensic interest, for which various types of methods have been proposed. The aim of the manuscript is to provide a review of the studies on the post-mortem DNA degradation used for estimating PMI. This review has been performed following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses and the PRISMA Guidelines. Several analytical techniques have been proposed to analyse the post-mortem DNA degradation in order to use it to estimate the PMI. Studies focused mainly on animal models and on particular tissues. The results have been mixed: while on the one hand literature data in this field have confirmed that in the post-mortem several degradation processes involve nucleic acids, on the other hand some fundamental aspects are still little explored: the influence of ante and post-mortem factors on DNA degradation, the feasibility and applicability of a multiparametric mathematical model that takes into account DNA degradation and the definition of one or more target organs in order to standardize the results on human cases under standard conditions.