Chapter 7 - Assessing Subsurface Decomposition and Potential Impacts on Forensic Investigations

Abstract

A cadaver is an energy source with an important role in nutrient recycling. Its decomposition is a complex process attributable to microbial, vertebrate, and invertebrate scavenger metabolic activities. These impact the surrounding environmental microbiota with potentially novel forensic applicability if key knowledge gaps are addressed. Most studies have to date (March 2017) focused on aboveground decomposition with very few published on the subsurface. This chapter will emphasize the importance of studies that are as close to real crime scene investigations as possible, such as clandestine graves, hence we report on how body decomposition affects soil microbial communities belowground. Our team used different experimental designs to investigate successional necrobiome shifts as a potentially novel tool to establish a postmortem microbial clock and augment estimations of postmortem interval and time since burial. Testing this potential and assessing limitations are illustrated presently with a mesocosm investigation where whole piglets were used as human taphonomic proxies. Grass from a domestic garden was included as an example of plant litter that may be incorporated in clandestine burials in real crime scenes.