One day, detectives may gather suspects together in the drawing room, and unveil their key piece of evidence – the family cat.
New research by Flinders University in Adelaide, South Australia, has shown that human DNA can be carried and transferred by animals such as cats and dogs.
That means, in theory, that detectives could use DNA carried in a dog or cat’s fur as evidence that a person has been near the animal.
It’s also possible that cats could accidentally transfer human DNA to a crime scene: this is potentially key evidence in criminal investigations, the researchers believe.
In collaboration with the Victoria Police Forensic Services Department, forensic science researchers Heidi Monkman and Dr. Mariya Goray, from the College of Science and Engineering at Flinders, collected human DNA from 20 pet cats from multiple households.
Detectable levels of DNA were found in 80% of the samples.
Interpretable profiles that could be linked to a person of interest were generated in 70% of the cats tested.
"Collection of human DNA needs to become very important in crime scene investigations, but there is a lack of data on companion animals such as cats and dogs in their relationship to human DNA transfer," says Monkman.
"These companion animals can be highly relevant in assessing the presence and activities of the inhabitants of the household, or any recent visitors to the scene."
An experienced crime scene investigator Dr Goray, an expert in DNA transfer, says this data can be very relevant when interpreting forensic DNA results obtained from a crime scene that includes pets.
"This type of data can help us understand the meaning of the DNA results obtained, especially if there is a match to a person of interest.
"Are these DNA findings a result of a criminal activity or could they have been transferred and deposited at the scene via a pet?"
The researchers say, "Further research is required on the transfer, persistence and prevalence of human DNA to and from cats and other pet animals and the influences animal behavioural habits, the DNA shedder status of the owners and many other relevant factors
To this point, further collaborative work on cats and dogs is currently underway at the Flinders University forensic laboratory.
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