Transfer and persistence of owner DNA on domestic pets

Abstract

Domestic pets are frequently present at crime scenes, the homes of victims and suspects, and other persons of interest associated or allegedly associated with a crime. The presence of traces of animal deoxyribonucleic acid (DNA) at a scene can be an investigative lead but could our furry friends also be depositing our DNA along the way? Routine contact with our domestic pets from a pat on the head, kisses, and hugs may all result in transfer of our DNA to an animal. In an effort to explore this possibility, the background human DNA on domestic pets was measured and whether any DNA attributable specifically to the owner of the domestic pet was assessed. Finally, whether the pet would transfer the owner’s DNA onto a smooth surface item was also evaluated. Ten domestic pets comprised of felines and canines were utilized for this study. None of the secondary transfer samples produced profiles that would be considered suitable for comparison to known DNA profiles or eligible to be uploaded to a DNA database. Approximately 53 % of all samples collected directly from the pet produced DNA profiles that provided support for the DNA profile under the proposition that the primary pet owner is a contributor rather than an unknown person is to the DNA profile obtained from the sample. However, it is unlikely to have results that support that the source of the DNA is the owner, rather than an unknown person, when the DNA is taken from an item that has been touched by the pet.