DNA in leech leads investigators to armed robber

October 21, 2009 at 12:00a.m.

CANBERRA, Australia (AP) — A leech found at a crime scene eight years ago led Australian police to a man who admitted robbing a woman in 2001, officials said Tuesday.

Forensic-science researcher Sally Kelty said the case is the first in Australia — and possibly the first ever — in which investigators have used DNA extracted from a bloodsucker such as a leech or a mosquito to solve a crime.

“It’s certainly unique and shows how the boundaries of DNA technology have been pushed since it was first introduced to Australia 22 years ago,” the University of Tasmania state researcher said.

The leech dropped off Peter Cannon as he and an accomplice tied a 71-year-old woman to a chair in her remote home in the Tasmanian woods Sept. 28, 2001, and stole several hundred dollars in cash, police said.

Detectives found the leech at the crime scene and extracted blood from it that they believed was from one of the two suspects.

They identified Cannon as that culprit when he was arrested last year on unrelated drug charges and authorities for the first time recorded his DNA profile.

Cannon, now 54, pleaded guilty in the Tasmanian Supreme Court on Monday to aggravated armed robbery. He will be sentenced Friday and faces a possible maximum of 21 years in prison.

Detective Inspector Mick Johnston, who was involved in the police investigation from the outset, said the leech was the only forensic evidence found at the crime scene.