The Significance of the Depositional Microenvironment in the Decomposition of Dismembered Body Parts

Abstract

A scarcity of experimental studies covering the decomposition of dismembered body parts has created a gap in knowledge of the effect of dismemberment on the estimation of post-mortem interval (PMI) and their post-mortem history in a forensic context. The aim of this study was to record the decay of detached body parts in some depositional settings where they are likely to be disposed of: burial, wrapping and freezing. A series of controlled laboratory experiments was carried out using Sus scrofa body parts and pork belly, to understand how ambient temperature, soil moisture, and wrapping and freezing of body parts affected their decomposition. Rates of decay were subject to a higher temperature and soil moisture level in a burial microenvironment, with metabolic microbial activity confirming the results. Temperature was a predominant factor in the decay rates of wrapped body parts, with a raised ambient temperature causing even higher temperature in the wrapped microenvironment, resulting in accelerated decay rates. Freezing decelerated the decomposition of body parts, retarding microbial growth and activity and causing differential decomposition between body parts. Freezing demonstrated morphological changes in body parts specific to this microenvironment. Predominantly Gram-negative bacteria that may be associated with body microflora were involved in decomposition in all three microenvironments. Taphonomic, chemical and microbiological analyses carried out in this study have a potential for forensic application in the examination of dismembered remains that have been deposited in freezing and indoor settings. Further experiments are necessary to understand buried decomposition patterns in field conditions.