Human DNA recovery in the context of wildlife crime: Comparison of trace DNA collection methods from wildlife specimens

Abstract

Forensic DNA analysis, used for the purposes of species, sex, individual, and, geographic determination of wildlife is one of the most applied forensic techniques in, wildlife crime investigations. However, in most other criminal investigations forensic, DNA analysis refers to human DNA profiling for the purposes of identifying victims, and/or perpetrators. The ability to recover human DNA profiles from the surfaces of, wildlife specimens, such as ivory or fur, opens up opportunities for identification of, individuals involved in wildlife crimes in the absence of other evidence types. This, study aimed to compare the effectiveness of four different human touch DNA recovery, methods, cotton swabs, flocked swabs, foam swabs, and minitapes, from the surfaces, of a range of wildlife derivatives. Groups of four participants handled ivory, elephant, skin, snake skin, conch shell, antler, and antelope fur. DNA was subsequently, collected extracted, quantified, and profiled. Foam swabs, a non-traditional method of, touch DNA recovery, recovered the highest average DNA concentrations and number, of alleles across all specimen types acting as an effective cross-substrate recovery, method. Flocked swabs performed as the second-best recovery method for all, specimens except when sampling from antelope fur. Minitapes and cotton swabs, showed comparatively poor performance during this study despite being the two most,common DNA recovery techniques currently employed by law enforcement. Ivory, yielded the highest average human DNA concentrations but paradoxically produced a, significantly lower number of donor alleles. Our results indicate fresh touch DNA, deposits are recoverable from multiple wildlife specimens and recommend that, attempted recovery of touch DNA should be a routine consideration by forensic, practitioners during wildlife crime investigations.