Who killed my dog? Use of forensic genetics to investigate an enigmatic case

Mariana Roccaro,Paolo Fais,Susi Pelotti,Carla Bini,Angelo Peli,Giuseppe Merialdi

doi:10.1007/s00414-020-02388-9

Abstract

Genetic testing of animal biological material has become a valuable tool in forensic investigations, and it is successfully used to identify unknown crime perpetrators, to unmask food frauds, or to clarify cases of animal attacks on humans or other animals. When DNA profiling is not possible due to inadequate amounts of nuclear DNA, mitochondrial DNA (mtDNA) testing is the only viable alternative, as in the case of shed hair samples. In this case, a dog was allegedly killed by wild animals while being hosted in a boarding house. Extraneous hair fragments recovered from the dog’s mouth and paws were subjected to genetic analysis: the cytochrome b gene located on mtDNA was amplified and sequenced in order to determine the species responsible for the killing. The mtDNA analysis provided evidence that the dog was killed by other dogs, thus unmasking a false wild animal attack and putting the case in an entirely different perspective.

Highlights

Genetic testing of animal biological material has become a valuable tool in civil and criminal forensic investigations [1,2,3]
We applied genetic analysis of cytochrome b gene (CytB) on animal hairs in order to determine the species of the animal(s) responsible for killing a dog
Single source mitochondrial DNA (mtDNA) sequences were obtained from all four hair samples and data from negative and positive controls excluded exogenous DNA contamination

Summary

Introduction

Genetic testing of animal biological material has become a valuable tool in civil and criminal forensic investigations [1,2,3]. The potential value of this method in forensic analysis can be considerable for the exclusion of an individual dog as a source of evidence [19, 30] In this case, we applied genetic analysis of CytB on animal hairs in order to determine the species of the animal(s) responsible for killing a dog. The haircoat was blood-stained and 14 wounds, 7–10 mm in size, were observed in various areas of the body: one on the right side of the nape, one on the dorsal side of the neck and three more on the ventral side, one on the left shoulder, one on the left thorax and two more behind the costal arch, two on the right thigh and three in the inguinal region. The signs of vital reactions in the affected tissues allowed to determine that the lesions observed where inflicted while the victim was still alive

Materials and methods

Results and conclusion

Compliance with ethical standards