Prof James Wallman, Faculty of Science, Medicine and Health and School of Biological Sciences, University of Wollongong New South Wales.
DEPENDING on the environment, it doesn’t take long for a dead body to become colonised by trespassing insects — and for two people in Australia, that means their phones are about to start ringing.
Professor James Wallman from the University of Wollongong and Dr Melanie Archer form Monash University in Melbourne are the only two forensic entomologists in the country who are routinely called upon by police for their insight on insects.
In murder mysteries and suicide cases, insect samples found at the scene can hold vital information for investigators. So for these two researchers, a love and fascination for insects has morphed into a part-time crime-solving job.
“It was during my Ph. D that police got in touch with me,” Prof Wallman tells news.com.au. They had heard about new techniques for helping date dead bodies and were looking for someone local who could maybe do the same.
Fast forward about 25 years and Prof Wallman is walking through an airport in Australia when he pauses in a shop and picks up a book about the gruesome Snowtown “bodies in the barrels” murders. As he flicks through the pages he is surprised to spot his name. The infamous Snowtown killings were just one of the cases he has helped police with.
At least, “they’re the recent ones that I can mention,” he says.
Prof James Wallman, fly expert from the University of Wollongong, shows off some of his samples.Source:Supplied
‘IT CAN BE PRETTY GRISLY’
Forensic entomologists are typically provided with insect samples direct from the crime scene or from a mortuary technician. Sometimes they are even required to visit the scene of the crime themselves.
“It can be pretty grisly,” says Prof Wallman. “You’ve got to have an interest in creepy crawlies.”
Flies and their larvae are one of the most common types of insects to find on a body because the female fly has a reproductive urge to find a suitable place to lay her offspring and the corpse of a dead animal or human is the perfect spot.
Most forensic entomologists are tasked with trying to determine “the post-mortem interval”, which is how long the person has been dead.
Typically they are able to give a minimum time since death by studying the age and composite of the insects that have inhabited the corpse. “On a nice summer’s day you might get instant colonisation if the body’s outside,” says Dr Archer.
“Or occasionally there might be fragments of insects that are associated with a person and you need to try and work out if they’re relevant to the case.”
She’s been in the field of entomology for nearly two decades and says it’s not just maggots that she has to analyse at the behest of police.
“While we do see some pretty common species that are associated with bodies, you can see just about anything,” she says. “Occasionally it might be parasites like head lice, or even (very rarely) fleas, or even parasitic maggots living on the flesh of living people.”
In the latter situation she might be asked to age a wound of a victim in a neglect case — typically a dependant person such as an elderly or disabled person in care. “That also goes for cases with little children, say a nappy that hasn’t been changed,” she says. Certain flies like to breed in faeces “so ageing those maggots might give you a good idea of when the nappy was last changed.”
Coloured scanning electron micrograph (SEM) of the head of a maggot.Source:Supplied
A VITAL PIECE OF THE PUZZLE
Prof Wallman and Dr Archer tend to take on cases that are within their respective regions and the number of cases can range from anywhere between six to as many as 20 or 25 a year.
With most murder investigations, the timeline of events is crucial to the investigation and insects can hold hugely telling clues.
They can even point to more obscure pieces of information. For example, drugs in the body can effect the growth of maggots that have made themselves at home in the corpse.
“You tend to be a jigsaw piece in a big puzzle,” says Dr Archer. “Maybe not breaking open the case so much as telling (police) something really important or correcting them on something they thought to be true,” she said.
“For example, a couple times I’ve had bodies that have been in certain locations and the investigators have assumed the bodies probably been dumped overnight … and I’ve been able to say the body’s been here for a few weeks.”
For Prof Wallman, who has been nicknamed Lord of the Flies, the work often lands him in front of a judge.
“The high profile cases inevitably translate from the giving of advice to police to testifying in court,” he says.
“I have given evidence in quite a lot of the most notorious cases where bodies lay undiscovered for quite some time before they were found”.
The Snowtown murders rocked the country.Source:Supplied
THE BODY FARM IN SYDNEY’S BUSHLAND
On the outskirts of Sydney lies a secret bushland facility with an abundance of decaying corpses. Known as the body farm, it is being used to study how human bodies decompose and is helping scientists conduct some unusual experiments.
It was established in early 2016 by Professor Shari Forbes, a forensic scientist from the University of Technology Sydney and is the only body farm outside of the United States.
Both Dr Archer and Prof Wallman spend time conducting research at the facility.
“Some of the sites are pretty confronting but the smell isn’t as bad as you might imagine,” Prof Wallman says.
He currently spends about two days a week at the farm and is working on experiments which study the temperatures of maggots when they’re developing in dead bodies. “The reason this is important is because temperature is one of the main determinates to how quickly maggots grow,” he said.
Researchers prepare for work at the Sydney body farm.Source:Supplied
Another important thing the site allows researchers to do is compare the findings made with similar experiments done on pigs, which until recently have been the human imitation prop of choice.
“My advice to anybody who wants to do this type of thing is make sure you’re interested in the root science that you’re pursuing,” Dr Archer says. “The forensic is just an application.”
Northern Michigan University is planning a new forensic anthropology major that will include what school officials call the world’s first cold-weather “body farm.” Body farms are research centers where the human body’s decomposition is studied in various environments. Courtesy: Fox News