July 13, 2000
Vol . 18, No. 6
July 13, 2000 Vol . 18, No. 6
By Marianne Meadahl
Homicide victims found at sea, or washed up on shore, could provide
investigators with crucial information needed to help solve the
crimes once the activity of the animals that infest them while
under water is more clearly understood.
That's why SFU forensic entomologist Gail Anderson (above, left)
is keenly watching what happens to six pig carcasses that she
has dropped and anchored in Howe Sound off Bowen Island.
Anderson's expertise on insect activity on homicide victims allows
her to pinpoint with great accuracy such details as time of death
and whether a body has been moved. She's taking the research to
new depths because murders that involve bodies found in water
can be among the toughest to solve.
"There is often nothing on which an investigator can pin
evidence, yet there exists a wealth of information in the form
of the sea creatures and the activity that occurs while a body
is immersed," says Anderson, a professor in SFU's school
of criminology who is frequently called on to help investigators
at crime scenes and to share her expertise in court.
Anderson's latest work is being funded by the Canadian Police
Research Centre in Ottawa and has drawn a wealth of supporters
from the Vancouver Aquarium, the RCMP and the Canadian Coast Guard.
All are supplying divers as well as boats and underwater recording
equipment.
The pig carcasses were dropped in late May, each weighted with
three cinder blocks connected by a chain and dropped several thousand
meters apart, to levels of 25-50 metres. Since they were dropped,
Anderson and dive crews have been out to sea about a dozen times.
Her initial results show significant promise. "We're seeing
a wide range of things happening in the underwater environment,"
says Anderson, who relies on divers to record activity and collect
species for later analysis.
During a recent dive, Coast Guard members found that the decomposed
carcasses, which had earlier sunk, were once again floating --
something Anderson says took longer than expected.
They found few signs of sea life around the pigs. A lone harbour
seal hovered near one of the carcasses.
The divers reported conditions back to shore, informing Anderson
of bite marks, missing body parts and the early onset of adipocere,
at which stage body parts affected become crumbly, almost resembling
cottage cheese. Anderson says it usually takes about three months
for the condition to appear, yet it is visible on one of the pigs.
Predators lose interest in feeding on spots where the condition
occurs.
"Every dive is telling us something new," says Anderson,
who expected divers to find more animals on or near the pigs.
"Once we learn what kind of activity is taking place we can
begin to discover what clues that activity can provide."
Tracking the pigs' conditions depends on the availability of boats
and volunteer divers. Anderson says she is receiving phenomenal
help.
"There's a real variety of experience and approach. The RMCP
and Coast Guard are more likely to notice decompositional changes,
while the aquarium divers, who can quickly identify unknown species,
immediately focus on the biology. The result is a well-rounded
view of what's happening to these pigs."
Coast Guard diver Tim MacFarlane is enthusiastic about his involvement.
"We come across a lot of people in the water, and this research
will give us a greater understanding of what to look for,"
he says. "It's an opportunity to have a role in a breakthrough
in science."
Anderson's earlier research targeting insects on pig carcasses
on land at sites throughout B.C. resulted in the first provincial
data base of insects. She is now working on a national data base
of bug-colonization patterns to help investigators working in
various geographic and climatic conditions.
That research is continuing in the Prairies. Anderson is also
setting up North America's first forensic entomology lab at SFU.
A former graduate student working with Anderson earlier conducted
similar research in freshwater conditions. "I am frequently
asked, 'what happens when bodies are found in water?', so it was
a natural next step in my research," says Anderson, who has
been planning the marine phase for four years. She hopes to create
a species index and database similar to those produced through
her other research.
Anderson recently created a training video for the RCMP on the
collection of important species and hopes to incorporate findings
from her marine research.
She plans to drop more pig carcasses into the sea this fall to
compare climatic conditions.
Anderson is also teaching a course she developed called biological
explanations of crime, for the first time this summer.
In August, Anderson will address the International Congress of
Entomology in Brazil, then teach insect collection techniques
to investigators at the Canadian Police College in Ottawa.
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