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Poking around in corpses in search of bugs is not everybody’s 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’s 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’s a smell you get used to very quickly. It’s like walking into a room where you can smell gas-after a few minutes you can’t smell it any more. It is certainly unpleasant but it’s no worse than what you see on television or in a Halloween movie. In fact I’ve seen a lot worse on television. It’s sad if it’s a crime scene, because then it’s someone who has died long before they should have done. On the other hand it’s very rewarding, because you feel like you’re doing something for society, for the dead person’s family. You’re bringing some closure to the family and giving them some understanding.

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’s 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’t 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’ve been dead. Some of them have been embalmed or autopsied, some haven’t. You might get an old lady who died of cancer with a horrific sore, or a 23-year-old crack cocaine addict who’s died in a car accident. These are not comparable. So it’s 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’t use a piece of beef. I don’t kill these animals, they come from a butcher, so it’s 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’s nature’s way of recycling and is no different from the recycling box in their office. If it wasn’t 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’s 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’s exciting purely scientifically.

You have an unusual job. How did you get into it?

It’s unusual in that there aren’t many people who do it, but it’s 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’t 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’t, any more than a police officer or a doctor. It’s just another way of trying to use insects to help people, and that was what I wanted to do. You can’t 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’s 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’t be used. Whereas I know that what I’m 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’s 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’re trying to compile a nationwide database for flesh-eating bugs. How many species do you have to catalogue?

Not that many. We’re 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’t 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’ve 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’ve 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’ve 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’s 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’ve helped catch poachers?

Yes, we’ve used this to identify the time of death of an animal, just the same as on a human. We haven’t 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’s 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’ve 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’m 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’t like needles. I will do anything not to have an injection.