The Revolution of Animal Genomics in Forensic Sciences

Nowadays, the coexistence between humans and domestic animals (especially dogs and cats) has become a common scenario of daily life. Consequently, during a forensic investigation in civil or criminal cases, the biological material from a domestic animal could be considered "evidence" by law enforcement agencies. Animal genomics offers an important contribution in attacks and episodes of property destruction or in a crime scene where the non-human biological material is linked to the victim or perpetrator. However, only a few animal genetics laboratories in the world are able to carry out a valid forensic analysis, adhering to standards and guidelines that ensure the admissibility of data before a court of law. Today, forensic sciences focus on animal genetics considering all domestic species through the analysis of STRs (short tandem repeats) and autosomal and mitochondrial DNA SNPs (single nucleotide polymorphisms). However, the application of these molecular markers to wildlife seems to have gradually gained a strong relevance, aiming to tackle illegal traffic, avoid the loss of biodiversity, and protect endangered species. The development of third-generation sequencing technologies has glimmered new possibilities by bringing "the laboratory into the field", with a reduction of both the enormous cost management of samples and the degradation of the biological material.

Recent advances in forensic biology and forensic DNA typing: INTERPOL review 2019-2022

This review paper covers the forensic-relevant literature in biological sciences from 2019 to 2022 as a part of the 20th INTERPOL International Forensic Science Managers Symposium. Topics reviewed include rapid DNA testing, using law enforcement DNA databases plus investigative genetic genealogy DNA databases along with privacy/ethical issues, forensic biology and body fluid identification, DNA extraction and typing methods, mixture interpretation involving probabilistic genotyping software (PGS), DNA transfer and activity-level evaluations, next-generation sequencing (NGS), DNA phenotyping, lineage markers (Y-chromosome, mitochondrial DNA, X-chromosome), new markers and approaches (microhaplotypes, proteomics, and microbial DNA), kinship analysis and human identification with disaster victim identification (DVI), and non-human DNA testing including wildlife forensics. Available books and review articles are summarized as well as 70 guidance documents to assist in quality control that were published in the past three years by various groups within the United States and around the world.

The Postmortem Interval of Two Decedents and Two Dog Carcasses at the Same Scene Based on Forensic Entomology

Simple Summary

This paper reports a case in which the minimum postmortem interval (PMI) of two corpses, a man and a woman, and two dog carcasses at the same scene was estimated using forensic entomology. The corpses were found in various states of decay and had been colonized by different insect species. A total of eight taxa of immature insects were isolated from the four corpses and carcasses. The minimum PMIs were estimated to be about 8.75 days for the corpse of the woman, 4.17 days for that of the man, 3.13 days for the dog carcass found in the stairwell, and about 28.80 days for the dog carcass found in the toilet. These estimations were consistent with other evidence. Although the soft tissue loss observed on the man’s corpse was more severe than that of the woman’s corpse, the woman had died much earlier than the man. The discrepancy is thought to have been caused by dogs’ feeding activity. This case report provides a reference point and new perspectives for forensic entomology research on estimating the minimum PMIs of multiple human corpses and animal carcasses found in an indoor environment.

Abstract

In this paper, we report the estimation of the minimum PMIs of two human corpses and two dog carcasses using entomological evidence. Corpses of an elderly couple and carcasses of four dogs were found scattered on different floors in a house. The scene was very dirty. In addition, there were 12 emaciated live dogs at the scene. The corpses had been eaten by the dogs to different degrees, but the damage was greater on the man’s corpse. After forensic examination, it was concluded that both individuals died of natural causes. The minimum PMIs of the two individuals and the two dogs were estimated using entomological evidence. The minimum PMIs of the other two dogs were not estimated because of the risk of contamination with the human corpses. Different insect species were found on each of the corpses and carcasses. The minimum PMIs were estimated as about 8.75 days for the woman, 4.17 days for the man, 3.13 days for the dog found in the stairwell and about 28.80 days for the dog found in the toilet. These estimations coincided with the time the woman stopped communicating with her daughter and when the electricity consumption at the house decreased significantly.

Molecular Sexing and Species Detection of Antlered European Hunting Game for Forensic Purposes

Simple Summary

The reasons behind illegal hunting can be widely different. There are also tricky methods that hunters use in the attempt to legalize their illegally-acquired trophies, specifically, introducing them in later seasons, and registering the eviscerated corpses as hinds. During certain periods of the year, hunters are only able to acquire a license for the shooting of female deer exclusively, with the male-hunting season beginning later. The eviscerated and decapitated carcass of the animal delivered to the wild game processing house cold store can be falsely registered as a female based on phenotype. If the hunting association suspects that the animal’s sex has been falsely reported, a forensic genetic investigation can be proposed. In other criminal events, there are no carcasses at all. When several biological remains left on the crime scene need to be tested, a fast and cost-effective detection of a given species or species-group might be substantial before subsequent analysis. Therefore, sex and species detection can provide an early-stage credibility to the resolution of illegal activities related to trophy animals, and additionally may disclose potential poaching disputes.

Abstract

Molecular sexing techniques are widely applied in conservation biology, although the range of forensically validated methods is fairly limited. The primary aim of this work was to develop forensically validated assays, using two PCR panels for sex and species assignment for the abundant antlered European game species: red deer (Cervus elaphus), roe deer (Capreolus capreolus) and fallow deer (Dama dama). Segments of the SRY and Amelogenin X/Y genes for sex determination, additionally species-specific cytochrome b regions for species detection were targeted and separately amplified in two multiplex reactions. These assays can reliably analyze trace amounts of DNA. The results of both can easily be visualized and interpreted practically, either on agarose gel or by capillary electrophoresis. These simple, fast molecular assays are able to affect the early-stage resolution of disputed or unsolved poaching cases, without the need of individualization or sequencing of forensic samples.

International Wildlife Trafficking: A perspective on the challenges and potential forensic genetics solutions

International wildlife trafficking (IWT) is a thriving and pervasive illegal enterprise that adversely affects modern societies. Yet, despite being globally recognized as a threat to biodiversity, national security, economy, and biosecurity, IWT remains largely unabated and is proliferating at an alarming rate. The increase in IWT is generally attributed to a lack of prioritization to curb wildlife crime through legal and scientific infrastructure. This review: (1) lays out the damaging scope and influence of IWT; (2) discusses the potential of DNA marker systems, barcodes, and emerging molecular technologies, such as long-read portable sequencing, to facilitate rapid, in situ identification of species and individuals; and (3) encourages initiatives that promote quality and innovation. Interdisciplinary collaboration promises to be one of the most effective ways forward to surmounting the complex scientific and legal challenges posed by IWT.

Development and implementation of a STR based forensic typing system for moose (Alces alces)

The moose is a highly prized game species in North America and is often the target of illegal harvesting. Forensic DNA analysis can be used to assist in investigations into wildlife crime by providing the link between the illegal incidents and suspects. In this study, we present the development and validation of a short-tandem repeat (STR) based forensic DNA test for the individualization of moose in Alberta and Yukon, Canada. We show that the markers used in the test are appropriate for forensic use and are sufficiently specific to moose. We also demonstrate the limit of detection and quantitation of the moose STR test on the ABI 3500 genetic analyzer. Lastly, we describe the population genetic structure of moose present in our forensic population database and make recommendations regarding the calculation of appropriately conservative forensic statistics.

Wildlife forensics: A boon for species identification and conservation implications

Wildlife trade and fraudulence in food, artefacts and cosmetic industries had raised serious concern in protection of the wild faunal diversity. Lack of proper tools and molecular based techniques for identification of wild species are some of the major constrains faced by the judiciary and law enforcement agencies while framing charges against poachers and illicit agitator. The emergence of wildlife forensics serves as a boon in solving long pending cases of wildlife crimes. Wildlife forensics have proven to be fast, accurate and reliable criminal investigation processes with comprehensive coverage and easy accessibility. It has also helped resolving taxonomic disputes, determining spatiotemporal genetic divergence, evolutionary history, origins and even endemism. Collaboration among inter-disciplinary fields has even led to engineered signature markers and phylogenetics for several species. Development in fields of genetics, molecular and evolutionary biology and other omics techniques have further contributed in accurate identification of species. Wildlife forensics, with the support of proper international mega database units for population reference, will be fundamental in wildlife investigations through its unlimited information sharing ability. The efficient conservation of species will, however, require a collaborative approach consisting of national policy makers, local stakeholders and implementation agencies in addition to experts from the scientific communities.