RCMP S/Sgt. Carl Sesely was skeptical about geographic profiling — until it helped him find the man who set fires to 28 occupied homes across Burnaby, B.C., more than 20 years ago.
The investigative technique uses the locations of serial crimes such as arson to identify the area where a suspect is likely living and where police should focus their search. Geographic profiling remains an important way to help advance serial crimes.
"Unlike on all those sexy television shows, geographical profiling doesn't solve crimes. It's just another tool that investigators use," says Sesely, who was an investigator at the Burnaby RCMP detachment at the time of the arsons.
After nine months, police still didn't have a suspect and fear in the community was growing. To help the investigation, Sesely asked the RCMP's Behavioural Sciences Unit to develop a criminal profile, which described the suspected traits and characteristics of the offender.
He also reached out to the Vancouver Police Department for a geographic profile because the RCMP didn't employ any at the time. The report he received included a colour-coded map of the hunting area.
The area where the suspect was likely living was red.
Still skeptical, Sesely showed the map at a public consultation meeting where he got a key tip from a property manager who owned a building in the target search zone. She told police that one of her tenants matched the suspect's description.
Sesely looked into the man's background, which led to his arrest.
Sesely says he was so impressed by the accuracy of the report, he decided to learn more. He became a certified geographic profiler in 2001.
There are 12 geographic profilers in Canada — seven are RCMP officers, two are with the Sûreté du Québec and three work for the Ontario Provincial Police. Many of these officers are also certified criminal profilers.
Clues about criminals
Every crime has a geographic element to it and provides clues about the offender, according to Sesely, who's worked at the RCMP for 33 years.
"We look for anything that helps us understand why they chose that location, how they got there and how they escaped," he says.
Officers can develop a geographic profile for serial crimes where there's a pattern of repeated behaviour committed by the same person in at least five different locations that are spread out in an area — as opposed to all occurring on one street.
"Studying geography is important because criminals' hunting patterns are typically predictable," says Sesely. "They might change their habits to throw us off for a while, but eventually they get lazy and go back to what's comfortable for them."
Officers insert the location of each relevant crime into a computer software program that analyzes the area where the crimes occurred. Police refer to this area as the hunting ground.
"The software looks at each pixel on the map and asks 'What's the probability that the offender lives here?' And then it does that 40,000 more times and calculates a probability score," says Sesely.
When a case doesn't meet the criteria needed to develop a geographic profile, profilers can still analyze the geography of a crime scene, whether in person or using satellite and panoramic street-view images.
In 2013, Sgt. Jean-Yves McCann of the Sûreté du Québec was a new geographic profiler working his first case in Saint-Jean-sur-Richelieu, Quebec, where someone was setting fire to BBQs, billboards and cedar hedges.
Having been trained by Sesely in 2013, McCann asked him to help develop a profile for the string of nuisance fires, which were steadily becoming more serious.
After a lengthy investigation of each crime site, the officers developed a profile and advised investigators where they should focus their search for the offender. Based on the recommendation, officers flooded the target search area on foot and caught the suspect in the act of setting another fire.
"His address was right in the peak zone," says McCann. "It was a classic example of how we use geo profiling to prioritize suspects and help catch the offender."