The presence of animal hairs on a person suspected of having committed an offence may provide a linkage between that person and/or their clothing (depending on where the animal hair was found) and the offence committed. Additionally, the presence of animal hairs on a victim may provide a link between that person and a place where a suspect has been, or the suspect themself. But it is not only people and places that can attract animal hairs, such hair has been found on adhesive tape.
In interpreting the weight to be attached to the finding of the hair the Association Triangle must be taken into account.
The presence of animal hairs at a crime scene can be indicative of a number of possibilities.
One drawback with the microscopic examination of animal hairs is that it will not lead to the identification of the donor animal and only in some cases to the breed of animal. This then means that bare information that a match occurs between animal hairs found at a crime scene and elsewhere is at best only circumstantial evidence. However, the value of such evidence can be bolstered depending on the rarity of the type of animal concerned, its prevalence in the community and the ease of transferability of its hair.
DNA analysis when the hair root is present can lead to the identification of the donor animal, but given that most shedding of hair occurs in the telogen (final) stage such may not be present.
Where cat hair is concerned, due to the nature of the animal and its self-grooming activity it is possible that epithelial cells contained in the animal’s saliva may have been transferred to its hair, those cells may contain DNA.
© Hadyn R Green 2012