A leech found at a crime scene eight years ago led Australian police to a man who admitted robbing an elderly woman in 2001, officials said Tuesday.Forensic science researcher Sally Kelty said today 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 bush on September 28, 2001, and stole several hundred dollars in cash from a safe, police said.
Peter Alec Cannon, 54, pleaded guilty to aggravated armed robbery in the Supreme Court in Launceston on the island state of Tasmania. 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.
Crown prosecutor John Ransom told the court that a policeman had picked up a leech from near a safe at the scene of the crime from which forensic scientists extracted blood and a DNA sample, according to a report in local newspaper The Mercury. Seven years later, when Cannon was arrested and charged with a drugs crime, police took a DNA sample from him and it matched the sample from the robbery.
Cannon, now 54, pleaded guilty in the Tasmanian Supreme Court yesterday to aggravated armed robbery. He will be sentenced on Friday and faces a 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.
"She's waited a long time for closure to this matter and it's nice to be able to deliver that," Johnson told ABC radio.
Police are still searching for Cannon's alleged accomplice.
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