An unusual pattern of post-mortem injury caused by Australian fresh water yabbies (Cherax destructor)

Forensic experiments on animal scavenging: A systematic literature review on what we have and what we need

Vertebrate scavengers frequently affect forensic casework by feeding on human remains or by scattering body parts and bones. Therefore, animal activity can influence complete recovery of bodies, trauma analysis, and the estimation of the postmortem interval (PMI), potentially hampering identification of the deceased and elucidation of the perimortem circumstances. Experimental research is well suited to investigate scavengers and their impact on carcasses over time, generating knowledge on the forensic relevance of certain scavenger species or communities. However, there are currently no systematised standards to conduct these investigations with a forensic focus, impeding comparison and synthesis of the studies. In our work, we performed a systematic literature review and found 79 publications featuring terrestrial experiments on vertebrate scavenging and/or scattering within a forensic context. We extracted 21 variables describing the study environment, experimental design and the specimens. The results show that there is considerable inconsistency in the study designs and that some of the variables are insufficiently reported. We point out research questions and areas that require attention in future studies, stressing the importance of infrequently mentioned or applied variables. Furthermore, we recommend guidelines to include and report a list of variables in forensic scavenging and scattering experiments. These guidelines will help standardising future research in the field, facilitating inter-study consolidation of results and conclusions, and consequently, inform forensic casework.

Uncovering Forensic Taphonomic Agents: Animal Scavenging in the European Context

Simple Summary

In forensic cases of exposed human bodies, vertebrate animals frequently pose challenges concerning remains recovery, identification, and the interpretation of circumstances of death. For instance, they can remove body parts, destroy skeletal features, and create “pseudo-lesions” that complicate trauma analysis. With this review, we highlight vertebrate scavengers in Europe that are of forensic relevance, including their typical behaviour and their inflicted lesions on bones and soft tissues. Here, we support forensic practitioners in recognising animal activity at the site of discovery and in interpreting the circumstances of death. Our review serves as a guide for the examination of animal-altered human remains and their found state by providing ecological backgrounds on various vertebrate species. In addition, this study provides an overview of the current state of research in the field of animal scavenging in forensics.

Abstract

Animal scavenging by vertebrates can significantly alter human bodies and their deposition site. For instance, vertebrate animals can cause postmortem modification to a body, alter perimortem trauma, influence decomposition rates, disarticulate and scatter body parts or evidence, and affect the identification of the deceased. Animal scavenging is a relatively common occurrence in forensic investigations. Even so, studies on the subject are scattered and rare, with most focussing on geographical areas outside of Europe. For that reason, we intend to collate the literature to provide an account of forensically relevant vertebrate scavengers in Europe, their impacts on human remains, and their implications for forensic investigations. Here, we provide an overview of forensic aspects where the knowledge of animal scavenging is crucial, as well as an account of potential scavengers of human remains in Europe and their typical alterations to soft tissue and, in particular, to bones. In addition, we are the first to provide a guide for forensic practitioners to identify the presence of vertebrate scavenging and subsequently inform outdoor search strategies for affected human remains.

Postmortem predation by a clowder of domestic cats

A 69-year-old man was found lying on the floor at his home address. According to the police report every room was filled with refuse and "thirty or so cats" were resident in the house. The body showed signs of extensive post mortem animal predation with opening of the chest and abdominal cavities, loss of soft tissues of the face, loss of soft tissues and organs of the neck, loss of the lungs and heart, and injuries to the liver, right kidney, stomach, transverse colon and cecum. The cause of death could not be determined from the autopsy given the absence of certain vital organs such as the heart and lungs, and the presence of early putrefaction. The case shows that considerable soft tissue, bone and organ loss may occur when a number of animals work in concert. The collective term for such a group of cats is a clowder. The extent of post-mortem damage from animal activity therefore relies not only on the species involved, but also the numbers of participating animals.