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Method validation is an essential step ahead of applying a method in forensic casework, to ensure the results will be admissible in court. However, unlike mainstream forensic disciplines, wildlife forensic labs often evolve from conservation-oriented units and may not have a strong foundation in generating data within a legal context. As such, the processes and principles of method validation may not be familiar or fully understood. In this paper we describe the process of method validation in a wildlife forensic science context. We provide guidance on the documentation required to take a DNA based method, which has been developed to identify a specific target species, through the validation process so that it is fit for use in forensic casework. This process has been agreed upon among members of the Society for Wildlife Forensic Sciences (SWFS) Technical Working Group (TWG) to illuminate the requirements for both practitioners and academics.

Eurasian beaver (Castor fiber) has recently been reintroduced in Scotland after more than 400 years of extinction and in 2019 received legal protection; deliberate killing or disturbing beavers without a license is therefore now an offense. We present a validated polymerase chain reaction (PCR)-based Eurasian beaver identification test for use in forensic casework where persecution of Eurasian beaver is suspected. Primers were designed to target a 271 base pair region of the mitochondrial cytochrome b (Cytb) gene in Eurasian beavers, and positive amplicons were confirmed by sequence analysis. Validation was carried out across two laboratories in Scotland, and included studies on sensitivity, specificity, reproducibility, and robustness. The developed test reliably detects Eurasian beaver DNA to the lower limit of 0.1 pg DNA input and differentiates Castor fiber from other species, including congeners. In conclusion, the developed test was successfully optimized and validated to identify Eurasian beaver DNA and will be a valuable tool in wildlife forensic laboratories in cases of suspected persecution of Eurasian beavers.

Over recent years, mounting pressure has been placed on countries to assess their role in the ivory trade, with a view to tackling the rapidly declining numbers of elephants, due to poaching. The United Kingdom has been identified as a large re-exporter of ivory. Despite much of this trade being reported as legal or antique ivory, such provision of ivory to meet demand is known to fuel illegal markets and provide trade routes for modern ivory sales. Aside from ivory species and age, further analysis to evaluate geographic provenance, can inform where an elephant had lived, and so identify a source region or population where poaching occurred. The purpose of this study was to determine the age and species of ivory objects surrendered or seized in the UK and assess their likely geographic provenance through comparison of results from mitochondrial DNA and stable isotope analysis to publicly accessible georeferenced African elephant databases. The results demonstrated that the objects tested from an airport seizure were modern and matched existing haplotypes allowing for regional geographic inferences (supported by both techniques) to be obtained for most of these objects. In contrast, antique and modern ivory was detected amongst the amnesty objects, and several new mtDNA haplotypes were identified. Regional geographic inferences were achieved for some but not all of the objects tested. Our findings show this combination of methods provides a wealth of information which, could provide insight into targeted elephant populations and assist in disrupting international wildlife trade networks.

European roe deer (Capreolus capreolus L.) are the most common game species in Europe, hunted for meat and trophies. Forensic investigations involving roe deer poaching may often benefit from an individual identification method to link a suspect to a specific incident. The current paper presents a forensically validated DNA profiling system for European roe deer called “STRoe deer”. This DNA profiling system consists of 12 novel unlinked tetra-nucleotide short tandem repeat (STR) loci and two sexing markers, with an allelic ladder to facilitate accurate genotyping. Validation results using 513 European roe deer samples collected from a single population from the Swiss Plateau demonstrated successful amplification of all 14 loci with as little as 0.05 ng of European roe deer DNA. Species-specificity tests showed that other members of the Cervidae family exhibited partial profiles and non-specific peaks, whereas most members of the Bovidae family showed just non-specific cross-species amplification products. Three different methods to calculate match probabilities for randomly sampled European roe deer genotypes resulted in median match probabilities ranging from 1.4 × 10−13 to 2.5 × 10−5. These methods accounted for possible population structure, occurrence of null alleles and individual relatedness. Based on these results, we conclude that STRoe deer is a robust genotyping system that should prove a valuable tool for individual identification and sexing of European roe deer to support criminal investigations.