Bulletin January 2018 Number 181

This article describes the unique challenges in investigating potentially suspicious deaths and incidents involving animals

ArroGen Veterinary Forensics celebrated its official launch in September 2017 at the University of Surrey. This partnership, between ArroGen Forensics Ltd and the School of Veterinary Medicine at the University of Surrey, represents the first integrated forensic service to support the investigation of crimes against or involving animals based in the UK.

Although launched in September, ArroGen Veterinary Forensics has been operating since the beginning of the year, working on prosecution cases from the police, RSPCA and other agencies and also conducting case reviews, including on behalf of the defence. Each time a new case enquiry is received, the first task is to develop a robust forensic strategy. One of the facets of the forensic strategy is to ensure that the correct tests or examinations are selected that will answer the questions that have been posed by the investigator, and ultimately will be asked by the court. This includes identifying the order that tests or examinations are performed to ensure that the best samples are recovered where possible without compromising any sampling that may follow.

When the case involves an animal, live or dead, instructed by the prosecution or defence, the approach we follow is to consider the animal itself as a crime scene. We consider the information already collected from the environment where the animal was recovered, and in cases where we are the second party to examine the animal, the samples and examinations already performed. Our partnership approach places us in the unique position that enables communication between experts in diagnostics across animal species in collaboration with forensic scientists across disciplines.

The scene examination, or review of materials recovered from the scene, including digital forensics where appropriate, of an alleged crime against or involving animals are approached in the same way as for any other crime scene investigation. The evidence types that can be considered from an animal are similar to cases in which humans are examined, and it is through a multidisciplinary approach that we seek to improve the quality and application of forensic science in cases involving animals.

Starting externally, many non-human subjects have haired, feathered or scaled skin. In a forensic context this a mixed blessing. From the perspective of the forensic veterinary pathologist, this can hide wounds and bruising until the animal has been clipped or skinned. It can also protect the underlying skin from abrasions and marks that might be caused by objects, surfaces or weapons in some cases. The silver lining is the ability of these additional skin appendages to trap other evidence types. These include, but are not limited to, gunshot residue, fibres, pollen, body fluids and debris from a scene or from an individual. The reverse is also true: there is more material for the animal to potentially leave at a scene. This could include hairs and feathers trapped or remaining on objects or surfaces and left at the scene for recovery and comparison. In animals with clawed extremities, these also offer abundant opportunity for recovering material or for leaving marks at scenes. Here, the experienced crime scene investigator and photographer are essential for one-to-one record photography, scene examination and strategic evidence recovery.

Entomology is used in the same manner as for cases involving humans, while forensic microbiology including the use of genomics is beginning to be explored in animals to provide intelligence regarding animal origin and post-mortem interval. Forensic biology is one field where the integrated approach of veterinary and medical expertise has overlapped to improve the quality of veterinary forensics. The investigative value of animal and microflora DNA has been improving over a number of years, and together with expertise and experience in the field of interpretation of human DNA profiles, the investigation of some types of crimes is aided. These include cases of alleged sexual abuse of animals, where human DNA and bodily fluids that have been deposited in or on an animal can be interpreted in the context of the case, and vice-versa, animal DNA or bodily fluids associated with alleged perpetrators can be interpreted in context with the case circumstances. Worrying of livestock by dogs is a similar scenario, albeit with two species of animal DNA, saliva and blood involved and advanced forensic techniques can be applied to differentiate the two.

Increased availability of advanced diagnostic imaging has also meant that animals previously disregarded as having no evidential or investigative potential may have some use, even if only for forensic intelligence. This could include exhumed or burnt remains and other cases of advanced decomposition. Imaging also offers an opportunity to examine the animal and obtain more information before proceeding to more invasive dissection or other destructive testing. For example, identification of projectiles before unwrapping the body, -evidence of trauma or other diagnostic information. Thus, a triage approach to examination and strategic and complementary testing can be -practised to optimise evidential value of the animal.

Malicious poisoning is a frequent allegation, although in the author’s experience these cases are infrequently corroborated and other causes of sudden death, such as underlying disease, are commonly diagnosed. The experience of toxicologists is invaluable to assist the veterinary pathologist, together with experts in veterinary pharmacology, because of the species-specific variables that enrich so much of veterinary science. Knowledge of metabolism, distribution and toxicity of various compounds can direct the sampling and interpretation in cases of poisoning. This is one example where dedicated research is paramount, and we are committed to building an empirical knowledge base on which various forensic results can be robustly interpreted in an animal context.

The techniques and fields mentioned are just some of the multidisciplinary approaches that facilitate the evaluation of the animal as a crime scene and this is optimised when it can involve experts across the forensic sciences, and not just be progressed as a specimen for the forensic veterinary pathologist.