A blood-swollen leech found at a crime scene eight years ago has led Australian police to an armed robber in an unusual twist of DNA technology, officials say.

Forensic science researcher Sally Kelty said Tuesday that the case could be the first in which investigators have used DNA extracted from a bloodsucker like 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 on Sept. 28, 2001, and stole several hundred dollars in cash, police said.

Detectives found the engorged leech at the crime scene and extracted blood that they believed was likely 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 on Friday and faces a possible maximum of 21 years in prison.

Detective Insp. 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.

He said he was happy with the guilty plea, especially for the victim, Fay Olson.

... contd.