08/24/07 (CAN):
Forensic Evidence Can Survive Flames
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In an interesting follow up to the 'Bug Woman' story in the August edition of 'X-Pro News', a researcher has said that murderers who torch bodies won't be destroying all the evidence.
Gail Anderson, a criminologist at SFU in Canada and a forensic expert, and Stacey McCann, a master's student, tested pig carcasses to see whether fire would destroy the bugs that set in during decomposition.
Anderson, who has worked with police and RCMP for nearly 20 years, says killers will sometimes leave a body in a car and ditch the car. But when they go back later and see the car still there, they'll set the car ablaze, hoping to destroy all the evidence.
"It's obviously a common scenario," she said. "Somebody murders somebody and they run away and they leave it.
"The easiest way to get rid of something that's a rotting corpse is to set [it alight]. Or that's what people think," said Anderson.
But in the tests Anderson and McCann carried out, enough insect corpses and pupa cases, or cocoons, survived that they could still estimate how much time had elapsed since death.
The entomologists also tested the effect of confinement in a vehicle on insect colonization. They found that of the three pigs they tested in three different cars, one seemed to be colonized differently and burned differently. It turned out it was the only one of the three cars to have a metal sheet between the backseat and the trunk. Now, Anderson can carry that knowledge with her on future cases.
She also says she is going to go back through previous cases to check the type of cars in which bodies were found.
Anderson has acted as an expert witness at the trial of Robert Pickton. Her knowledge is useful to police, said the spokesman for the Integrated Homicide Investigation Unit.
"We do use entomology on cases where the bugs are present," said Cpl. Dale Carr. "They're generally on bodies that are discovered more than a couple of days [after death]. If there's a presence of bugs and flies and maggots, we do call the entomologist.
"We affectionately refer to her as the bug lady," he said.
"Their science can help us considerably to establish a timeline."
© X-Pro 2007
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