Dna Surprisingly Easy To Find, Trace It Even Can Be Recovered From Objects Casually Touched By Hands

Think you’re a tidy person? A new study suggests you’re leaving DNA all over the place - on pens, keys, coffee mugs - and it can be traced back to you.

That provides a handy tool for investigating crimes, say forensic scientists who recovered DNA from a slew of everyday things and matched it back to the people it came from.

The technique has already been used to provide evidence in cases of attempted murder, rape, armed robbery, extortion and drug trafficking, the Australian scientists said.

At the same time, the researchers found that people can pick up other people’s DNA on their hands. That raises at least the possibility that a person could plant or accidentally leave somebody else’s DNA at a crime scene.

Most people know DNA can be recovered from blood or semen, and they may have heard that evidence in the Unabomber case includes DNA recovered from some licked stamps.

Scientists said it’s no surprise DNA can also be found on objects that were only casually touched by hands.

Still, the Australian work is striking in suggesting that so much DNA can be recovered so consistently from so many things, experts said.

“It’s more common than we would have expected. It seems less a chance occurrence,” said Ron Fourney of the Royal Canadian Mounted Police.

The new work is presented in today’s issue of the journal Nature by Roland A.H. van Oorschot and Maxwell K. Jones at the Victoria Forensic Science Center in Victoria, Australia.

It’s not clear where the DNA that people shed casually comes from, van Oorschot said. But there is some evidence that “naked” DNA - DNA that has escaped from dying cells - can be on the skin, he said.

The researchers recovered DNA from leather briefcase handles, pens, a car key, a locker handle and telephones, and found the samples matched the DNA of people who regularly used each item.