“Forensic entomology was first reported to have been used in 13th Century China and was used sporadically in the 19th Century and the early part of the 20th Century, playing a part in some very major cases. However, in the last 20 years, forensic entomology has become more and more common in police investigations.” – Dr. Gail Anderson, Forensic Entomology: The use of Insects in Death Investigations
Forensic entomology is a type of forensic science that uses the method of collecting insect specimens from a dead body and analyzing their species or stage of development to determine a range of time of death.
Other factors determined by forensic entomology include if a dead body has been moved or disturbed after death, if there are drugs present in the body, the season in which someone died, and wounds on a body (Dr. Gail Anderson, Forensic Entomology: The use of Insects in Death Investigations)
Dr. Gail Anderson is a professor at the SFU School of Criminology, Co-Director of the Centre for Forensic Research, Associate Director of the School of Criminology at SFU, and President of the Entomological Society of Canada.
The Forensic Entomology lab is part of the Centre for Forensic research and was built in 2007. Its primary functions are research, teaching, public outreach, and active case work. There are many rooms within the lab, two of which have RCMP protected security as this is where Dr. Anderson works on active homicide cases from all over Canada.
Dr. Anderson was involved in the infamous Robert Pickton case. She testified on evidence found on three women. Pickton was charged with the murder of two of those women and a third Jane Doe who he was not charged with murdering.
Successional waves of insects: As a dead body breaks down and begins to decompose, it goes through physical and chemical changes which attracts various insect species at each stage. This method can be used up to several years after death, and can determine the season in which the person died
“Therefore, with a knowledge of the regional insect fauna and times of carrion colonization, the insect assemblage associated with the remains can be analyzed to determine a window of time in which death took place.” – Dr. Gail Anderson, Forensic Entomology: The use of Insects in Death Investigations
Maggot age and development: is used in the first few weeks after death, and can give a date of death in the range of a day or less. This method uses the insects that are the first to arrive on a dead body: Calliphoridae (blowflies). They lay their eggs in soft parts of the body such as wounds, dead tissue, or in natural orifices. These eggs develop in a predictable cycle, each stage taking a known amount of time to complete. (Dr. Gail Anderson, , Forensic Entomology: The use of Insects in Death Investigations)
“A blowfly is a type of common black fly. You actually see them when you leave meat out. So they themselves like water and sugar, and are attracted to sweet foods. But when they can sense blood in the area, fresh blood, they know that that’s what their eggs will like and that’s what they’ll actually try to lay their eggs on. So if you’re ever doing a barbecue, make sure you keep an eye on your meat because if you see these black flies with the shiny blue and green backside, you’ll know that they’re trying to lay their eggs on your meat.” – Vienna Lam, Forensic Entomology Lab Manager, SFU
According to Dr. Anderson, forensic science can be divided into pure science and police driven science. Police driven science includes evidence such as fingerprints and bullet matching. These are not based on the scientific method and so they haven’t had the kind of empirical support that pure science has had. They have not yet been proven in a scientific context outside of forensics and until recently these types of evidence have not been researched outside the policing community. Dr. Anderson has said this doesn’t mean there is anything wrong with this kind of evidence – they’re just “born out of a different thinking set.”
With pure science, such as forensic entomology, experts will never say “it’s a match.” For example, scientists looking at DNA will never say it’s one hundred per cent a match. “Even when we’re very very sure, you know the chances of it being somebody other than your DNA is one in 220 trillion, so obviously it can’t be anybody but you we still say it in that format,” Dr. Anderson says.
The insects used in forensic entomology are not only attracted to corpses. They are attracted to soft, dead tissue on which they lay their eggs. This dead tissue can be present on a living being in various forms.
Seniors: elderly people who are bedridden can suffer from bedsores and incontinence. If bandages or bedding is not changed frequently, insects can become attracted to those wounds and dead tissue.
Babies: if a baby has not had a diaper change in a significant amount of time, they will suffer from various skin conditions.
Animals: Dr. Anderson frequently works on cases of animal abuse for the SPCA. Maggots are often present on animals in cases of neglect and animal cruelty.
“This is just about the only thing you can do to quantify the abuse. You can give a time frame to it.” – Dr. Anderson