Chemical Analysis Tools for Rapid Determination of Postmortem Interval On-Site: Application of Smart City Principles to Forensic Science

Abstract

From ancient times to our days, in Smart Cities estimating the time of death or postmortem interval (PMI) is one of the most important and frequent questions in forensic and legal practice and its transcendence involves not only religious matters but also the application of the law and good governance. The importance of PMI estimation includes the application of the law, inheritance claim, payment of life insurance and in some countries to know who died first during the rescue of a victim of kidnapping if all those involved had died. These situations require that the forensic laboratory can move to the crime or accident scene with analytical technologies capable of collecting measurements within minutes. Pieces of evidence which are essentially products of degradation of keratotic materials such as skin, hair, bone, and nail, are associated with human remains in burial environments and can be analyzed in terms of their molecular structure viatheir vibrational spectra. In this regards, the aim of this study is twofold. Firstly to develop an optical analytical methodology we employed the light scattering, which is a physical phenomenon where the interaction of light with matter reveals valuable information about the molecular structure and dynamics of the material under examination. Secondly, this study aims to demonstrate that cartilage as a biological model can reflect through the vibrational spectra the main changes in collagen type II structure and estimate the PMI. An exciting finding in this research project is that cartilage is an excellent material for pattern evidence that changes over time and cartilage viscoelastic properties show considerable changes during decay. This study has made novel contributions since the approach presented is a new parameter for the determination of human PMI by optical metrology applied to Forensic field in a Smart Cities environment.