Bad News for Criminals: Introducing the Crime Thwarting Leech

Police in Tasmania, Australia have solved a case using DNA extracted from a leech found at a crime scene. This might be the first time anyone in the world has solved a case using such a method.

8 years ago, the home of an elderly woman was invaded by two robbers. They tied the 71-year-old woman to a chair, poked her body with sticks, and robbed her of $550(AUS).

One of the few things police found at the crime scene was an engorged leech. It was logical to assume that the leech might have bitten one of the perpetrators, since neither the woman nor the police present at the scene had been bitten by the leech.

"For the leech to latch onto the offender as he was probably traveling through the bush to get there, to drop off at the scene, to be found during the examination, and to extract the DNA sample from the blood in the leech -- you know, it's a fairly unique set of circumstances," Inspector Mick Johnston said.

The case went cold because there was no match to the DNA found in the leech to other DNA logged in the database at the time of the incident-- however, 8 years later, a man named Peter Alec Cannon was picked up for a drug offense and his DNA was subsequently logged into the database. And lo and behold- a match! (1)


(1) http://www.cnn.com/2009/WORLD/asiapcf/10/20/australia.crime.leech/index.html?iref=mpstoryview