Wildlife Forensics: DNA Analysis in Wildlife Forensic Investigations

Wildlife forensics has only recently entered the forensic scenario, but is rapidly gaining importance and is increasingly being applied to caseworks, in compliance with the laws on the conservation, protection, and welfare of wildlife and to warrant animal rights. Crimes against animals are currently widespread worldwide, being a huge source of income for criminals when wildlife trade and poaching of exotic, rare, protected or threatened species are concerned. At small geographic scale, poaching and illegal harvest of wild animals can rage on endemic populations of high conservational value; thus significantly affecting local biodiversity. DNA analysis is now becoming an essential tool available to law-enforcement authorities, and is increasingly crucial for assigning the responsibility of crimes against animals. Typically, methods and procedures of wildlife DNA analysis are originally developed for animal genetic research and only subsequently are they transferred to forensic frameworks. As in human forensics, for caseworks where wildlife is involved, investigations start with the collection of evidence on the crime scene. Biological samples are then submitted to different molecular methodologies for DNA testing, depending on the queries posed by the law enforcement. In wildlife forensics, DNA analysis is mostly requested to identify: unknown species from parts of animals that have lost their identifying morphological features; gender, when animal crimes are sex-specific; single individuals for matching DNA profiles between 358seized carcasses and biological traces from poaching sites; population of origin when the species is protected in one area of its distribution and not in another; paternity/maternity and family relationships to ascertain whether captive-bred individuals are possessed legally or wild-caught animals have been unlawfully removed from their habitats. Operationally, PCR-based DNA amplification, sequencing, fragment analysis and single nucleotide polymorphisms analysis are currently the most popular techniques in wildlife forensic laboratories, even though new approaches like whole-genome sequencing through next-generation sequencing technology, are rapidly making their way. Standardization and validation of procedures, quality assurance, and biostatistical treatment of molecular data, following in the footsteps of human forensics, are playing an increasingly important role in wildlife DNA forensics, especially in the view of admissibility of forensic results as scientific evidence in court.