Cat could help solve a crime – Do you often get the feeling that your cat knows more than meets the eye? It is possible that you are right and that your pet hides secrets that you did not expect, such as the identity of the person who broke into your house a few days ago. This is the conclusion reached in a recent study.
The study has been published in Forensic Science International: Genetics Supplement Series and is the first to look at how pets, and cats, in particular, could contribute to DNA transfer at a crime scene .
Human beings scatter our DNA wherever we go: hair falls out, dead cells… even slight contact with an object will leave traces of our genetic material. And what do the kittens have to do with all this?
The answer lies in its fur, and that is that the cat’s fur may contain a sufficient amount of DNA that someone close to it has “spilled“. Therefore, although the animal can tell you little about the thief who entered your apartment and robbed you, it could help to identify the perpetrator of the crime.
“Human DNA collection has to be very important in crime scene investigations, but data on companion animals, such as cats and dogs, as it relates to human DNA transfer is lacking,” says the coroner. and study author Heidi Monkman of Australia’s Flinders University. “These companion animals can be very relevant in assessing the presence and activities of the home’s inhabitants, or any recent visitors to the scene.”
In recent years, DNA analysis has been refined to such an extent that even tiny traces of genetic material can be used to investigate a crime scene. Tactile DNA, which is obtained from a surface that has not necessarily been touched by the suspect, is not enough on its own to identify someone, but it can be used to support other evidence or even rule out people. This is where cats come into play, as cells that have been shed from someone’s skin or hair that has fallen may have landed on the animal’s fur.
Two forensic experts and an experienced crime scene investigator participated in this study. Also 20 cats from 15 homes. The scientists went to the homes and took samples from the pets, specifically the hair on the right side of each cat and DNA from all but one child of the human participants. The swabs from the cats and the DNA samples from the humans were then processed.
In addition, the human participants had to fill out questionnaires about the behavior and daily habits of the cats. This included how often the pet was touched, and by whom, in the home.
The scientists found detectable levels of DNA in 80% of the cat samples. There were no significant differences between the amount of DNA present and the time since the last contact with a human, nor whether the cat had longer or shorter hair.
The team was able to generate DNA profiles of 70% of the animals in the study that could be interpreted well enough to be linked to a human. Most of the genetic material came from people who lived with the cat. However, unknown human DNA was detected in six cats.
Of those six cats, two had spent a lot of time in the bed of the boy whose DNA samples were not taken, which would explain the mystery. It is unknown, yes, where the unidentified DNA of the four remaining cats comes from. The curious thing is that none of the homes had received visits for at least two days before the samples were taken.
Another curiosity of the study was that of a home in which two people and two cats lived. One of the kittens was a sphinx cat, which has no hair, and the other was a short-haired ragdoll. Well, the bald cat had DNA from a third unknown human and the fluffy cat did not. Both pets interacted in the same way with humans in the home.
Possible sources could include the direct transport of DNA from a human, such as by petting, or by brushing the cat against a contaminated surface. The DNA could also have remained from the last time the cat had contact with a visitor.
“The mode of transfer of this DNA to the cat, and its persistence in them, is unknown,” the researchers write. “Further research is needed on the transfer of human DNA to and from cats, and the persistence of human DNA in cats, and what may influence the different levels of DNA found in cats, such as behavioral habits, and the owners’ state of molting”.
