Fido may keep criminals away in the first place, but Fluffy can help the police bust them. As any cat owner knows, felines shed a lot of fur, and that fur — which clings to the skin, clothing and shoes of visitors — can be used as forensic evidence.

"The increasing popularity of the domestic cat as a household pet has unknowingly fostered the distribution of potential crime scene evidence across millions of households," researcher Robert Grahn told Discovery News. "Cat fur obtained from a crime scene has the potential to link perpetrators, accomplices, witnesses and victims."

Scientists have established a DNA database that will allow cat fur to be used more effectively as evidence in criminal cases. The database focuses on mitochondrial DNA, which is passed down through the maternal line. This type of DNA has a high mutation rate, so it’s more identifiable between individuals, and its genes exist in high amounts.

Grahn and his team at the Department of Population Health & Reproduction at California’s UC Davis have collected DNA samples from hundreds of cats during routine spay and neuter surgeries.

Another form of DNA called standard short tandem repeat (STR) has already been used to convict an accused murderer. Douglas Beamish of Canada had the fur of a long-haired white cat stuck to one of the pockets in his jacket, which was genetically linked to the cat of his victim. Beamish is currently serving a 15-year sentence.

The DNA test created for the STR marker, called “Meowplex”, will be used in tandem with the new mitochondiral DNA database to provide criminal investigators with a furrific resource for solving cases.

CSI: Felines! Cat fur DNA busts criminals
Cat fur sticks to everything, including criminals, and DNA obtained from that fur can place a perp at the scene of a crime.