University of Technology, Sydney

It's not the most savoury topic for research, but the discovery that maggots feeding on a burnt body could be silent witnesses to a deliberately lit fire promises to be an important new tool for police.

Lisa Mingari, a PhD student in forensic entomology at the University of Technology, Sydney, has already proven that maggots retain detectable traces of petrol or kerosene after digesting flesh that has been set alight.

Now she is preparing for a field trial to see if fly larvae and the pupal cases left from their transformation into adults will preserve signs of the use of accelerants after fuel has evaporated from other physical evidence at a crime scene.

Towards the end of this year Ms Mingari plans, with the help of the NSW Fire Brigade, to burn one or more pig carcasses in a remote area and leave them exposed – with protection from scavenging animals – for "as long as possible".

An unburnt carcass will be the control and the mock-up crime scene will include other kinds of potential evidence, such as the remains of clothing.

"Usually, for petrol or kerosene to be successfully detected fire debris samples must be collected promptly," Ms Mingari said. "However, this may not be possible if a body is located several days after it has been set alight.

"If the field trial shows that fly larvae and their pupal cases retain evidence of accelerants longer than fire debris it will be another useful tool for fire investigators.

"Initially I wanted to see if it was in fact possible to collect larvae that had been feeding on meat burnt with an accelerant and detect that same accelerant.

"As this approach was completely novel I had to design my own testing method. I decided to limit the study to petrol and kerosene due to their prevalence in arson cases.

"That first work showed that I didn't even have to crush the maggots to get positive results for accelerants."

In the lab tests Ms Mingari burned lamb neck chops and left the meat out for eight hours before applying the larvae of "Lucilia cuprina", the bluebottle fly. "It's a species that is found worldwide and is known for being one of the first to arrive when body is left outside," she said.

---

Editor's Note: Original news release can be found here.