These time-marking bugs are the most gruesome clues in forensic science
THE FIRST murder solved with the help of insects, per an account written in the year 1235, took place in China.
A villager was found slashed to death. The judge summoned local farmers and told them to bring their sickles. As the farmers stood in the summer heat, insects swarmed around one man’s tool - drawn to traces of blood left on the blade.
The man confessed. The telltale bugs, Hawaiian forensic entomologist M. Lee Goff wrote in his 2000 book, “A Fly for the Prosecution,” were “certainly blow flies.”
Seven centuries later, investigators still look to blow flies, maggots and other insects for evidence. Bodies are ripe “to be colonised by plants and animals,” Goff wrote, like volcanic islands freshly erupted from the sea. Some bugs can smell a decomposing body from miles away. They come to feed. Or they’ll lay eggs in the nose, eyes and throat. Based on who’s still eating or whose eggs have hatched when the victim is discovered, experts can sketch a rough history of the corpse.
But there are limits to what scientists can divine from insects. Bug behaviuor rarely provides precise timelines. In particular, “numerous weaknesses and erroneous beliefs” plague the use of insects to reveal whether a body has been moved, according to the authors of a report published in the journal PeerJ.
Damien Charabidze, a forensic entomologist at the University of Lille in France, reviewed more than 170 scientific articles and case reports about bugs and corpse relocation. He found that, although TV shows and textbooks imply that bugs can act as a corpse’s six-legged return address, this rarely bears out in practice.
“Only a few forensic cases have actually been solved using such a method,” he said. Those that were required “good timing, an accurate sampling, a little bit of luck” as well as “a huge background knowledge” in local biology.
It’s relatively easy to detect when corpses were moved from water to open air, as long as the animals - such as aquatic midges or snails - remain on the body. Jeffrey Wells, an entomologist at Florida International University who was not involved with this report, said there is also a big difference between buried corpses and those left in the open.
Tiny insects called scuttle flies are “very good at crawling into tight spaces,” he said, such as buried bodies or those wrapped in plastic and put in the trunk of a car. But you’ll hardly ever find them on exposed bodies. Unless the corpse was moved. “It’s not a ridiculous scenario. Bodies do get buried and dug up again,” Wells said. — Washington Post.