Poking around in corpses in search of bugs is not everybody鈥檚 cup of tea. But Gail Anderson, a professor of criminology at Simon Fraser University in British Columbia and one of only a dozen certified forensic entomologists in North America, does it for a living. She even finds it fun. Her job is to discover how and when somebody died by looking at the insects on their body. She is also an expert in murder victims that end up in water. Nicola Jones asks her about life and death at the deep end, and finds out why she鈥檚 been depositing dead pigs across the Canadian countryside.
What was it like when you saw your first dead body?
Not as unpleasant as you would expect. It smells, but it鈥檚 a smell you get used to very quickly. It鈥檚 like walking into a room where you can smell gas-after a few minutes you can鈥檛 smell it any more. It is certainly unpleasant but it鈥檚 no worse than what you see on television or in a Halloween movie. In fact I鈥檝e seen a lot worse on television. It鈥檚 sad if it鈥檚 a crime scene, because then it鈥檚 someone who has died long before they should have done. On the other hand it鈥檚 very rewarding, because you feel like you鈥檙e doing something for society, for the dead person鈥檚 family. You鈥檙e bringing some closure to the family and giving them some understanding.
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Where do pigs come into it?
We use pig carcasses as human models. We bury them, leave them above ground, in the shade, in marshland. We have suspended some in Lake Ontario and in Howe Sound on the coast near Vancouver. Any situation in which you might find a human homicide we will recreate using a pig carcass from the butchers.
Why pigs?
Pigs are the closest model we have to humans for decomposition. They are omnivores like us, so their gut flora and fauna are very similar. If you used a carnivore such as a cat, or a herbivore such as a cow, their decomposition would be very different because their gut bacteria would be different. Pigs are relatively hairless, like us, so their skin will decompose very similarly to ours. Their skin is in fact almost identical to ours. If someone is badly burnt, you can use pig skin as a graft. You can also get a pig that鈥檚 roughly the same size as a human torso.
What happens to a pig after it has been in water for a long time?
Decomposition in water is quite different to decomposition on land. On land the gut decomposes first, whereas in water the extremities are the first to go. They get nibbled by everything: fish, shrimp, crabs. We roped the dead pigs so that they could float or sink, depending upon what the gut bacteria did. If they got tangled up in the rope close to the sediment they would go very quickly because all sorts of things live in the sediment and they eat anything. Once they start to get eaten they fall apart.
Would you learn more if you used a human body instead of a pig?
Not really. It wouldn鈥檛 be possible to get 10 male 28-year-old Caucasians at the same time, which is what you need for a scientific experiment. You will get an occasional corpse donated to science, but they could be anybody. You may not know how they died, you may not know how long they鈥檝e been dead. Some of them have been embalmed or autopsied, some haven鈥檛. You might get an old lady who died of cancer with a horrific sore, or a 23-year-old crack cocaine addict who鈥檚 died in a car accident. These are not comparable. So it鈥檚 fascinating anecdotally but from the point of view of a true scientific experiment it is less valuable than using dead pigs.
What is it like when you pull a decaying pig from the water?
I hate using whole animals. I would rather use something else, but if I have to testify in court I can鈥檛 use a piece of beef. I don鈥檛 kill these animals, they come from a butcher, so it鈥檚 not very different to buying a big pork chop. People have been really disgusted at the idea of a decomposing pig until I point out that it鈥檚 nature鈥檚 way of recycling and is no different from the recycling box in their office. If it wasn鈥檛 for these insects that recycle the nutrients from dead animals, we would be neck deep in dead animals in a few weeks.
Is the actual research-looking at dead animals-enjoyable?
Oh very much so. That鈥檚 what I am, a researcher. People have looked at the ecology of rainforests and all that sort of thing but the ecology of decomposition is not very well understood, particularly in an aquatic environment. Pretty much everything that we are doing is a new area, and it鈥檚 exciting purely scientifically.
You have an unusual job. How did you get into it?
It鈥檚 unusual in that there aren鈥檛 many people who do it, but it鈥檚 a very popular field. We usually turn down between five and 10 students a week from around the world. The university has been involved in it since the 1970s. My first degree was in zoology, but primarily entomology, from Manchester University. I intended to end up in the medical veterinary field using entomology. Then one of the people who got involved in forensic entomology originally at Simon Fraser University decided he didn鈥檛 really enjoy it because it can be unpleasant. So he quit and my supervisor was looking for somebody else to take over. I decided to give it a go. That was 13 years ago.
Did you have any doubts about the job?
I worried that it might make me paranoid, that I might feel threatened by criminals at some point, or that I might start to think about death more-but you don鈥檛, any more than a police officer or a doctor. It鈥檚 just another way of trying to use insects to help people, and that was what I wanted to do. You can鈥檛 get any more helpful than using them to help catch a killer-or, more importantly, to exonerate an innocent person.
What else do you find so appealing about forensic entomology?
It鈥檚 the immediacy of it. I did my PhD in a disease called sweet itch (Culicoides hypersensitivity) that affects horses. I discovered a cure for it. But no drugs company wants to invest in something that is only going to work for a few ponies. So although I did what I set out to do, and I got the degree that I set out to get, there is not a lot of satisfaction in knowing that what I did has never been used, and won鈥檛 be used. Whereas I know that what I鈥檓 doing here could be used tomorrow.
So are murder victims really dumped into oceans as much as the movies would have us believe?
It depends on where you are. Vancouver is a big city on the edge of the ocean and it鈥檚 obviously very tempting there to dump a body in the sea, especially if you have a small boat. The problem with bodies in the water is that it is very difficult to tell if they were murdered or not. Did he jump or was he pushed? This is just one of the things that we are trying to solve with the research. Were those wounds created by the propeller of a boat after death, or was she knifed?
You鈥檙e trying to compile a nationwide database for flesh-eating bugs. How many species do you have to catalogue?
Not that many. We鈥檙e only looking at two major groups, the beetles and the flies. Both contain millions of species, but the carrion community is relatively small. There may be a lot of insects on a body but the diversity isn鈥檛 that great-maybe a hundred species.
How accurately can you pin down the time of death?
It depends how long somebody has been dead. If they have been dead for just a few days, I can give you the hour or a range of hours. If they have been dead up to three or four weeks, I can get it to a day, or a range of days. An aquatic environment is difficult to work in because there are so many variables, such as tide and temperature. I鈥檝e been with colleagues who have brought up the body of a diver who has been dead for six hours, and his face has gone. Yet I鈥檝e also seen a body pulled up weeks after death and they have been able to have an open-casket funeral. So it really depends on the scenario.
You鈥檝e even helped archaeologists. How do you do that with forensic entomology?
Insects leave behind evidence of themselves. For example, beetles can leave the outer protective casing of their wings-think of a ladybird鈥檚 spotted shell. Flies can leave their pupal cases, and caterpillars a chrysalis. This evidence can tell us about the insects that lived on a body. There are many questions about ancient human remains that I can help with. If a person was carrying food that had insects on it, would that indicate that he cultivated a crop or that he was collecting wild grasses? What would the parasites he carried say about what he was eating? If those parasites come from an area a long way away from where he was found, would that indicate that he travelled a great deal or that there was trade going on?
And you鈥檝e helped catch poachers?
Yes, we鈥檝e used this to identify the time of death of an animal, just the same as on a human. We haven鈥檛 done many cases- conservation officers are not nearly as aware of this evidence as police officers. One case comes to mind, in which two bear cubs were killed for their gall bladders. They were just four or five weeks old. I was able to tell when they died, and that led to a conviction.
What鈥檚 the worst part of your job?
I have never been particularly delighted to testify in court. It can be very adversarial. The opposing side try to put you down and can be very rude. When you are inexperienced it can be unnerving and that certainly makes me wonder why I am putting myself through this when I have a perfectly normal job too. But in most cases they are extremely professional. I鈥檝e submitted evidence in about 130 cases, and been called to testify in 15 or 16 of those.
What do you do in your spare time?
I鈥檓 an animal nut. My house is full of dogs, cats, exotic animals. I have sugar gliders, hedgehogs, things like that.
Does anything make you squeamish?
I don鈥檛 like needles. I will do anything not to have an injection.