"Identifying 'the hunting area'
Geographic profiling is based on the theory that criminals tend to operate in areas they are familiar with — what Rossmo calls "the hunting area."
These profilers try to zero in on the likely home or work place of the killer by analyzing the sites of the attacks, the places where bodies were left, the availability of transportation and the types of roads and highways to both the attack sites and dump sites.
Rossmo says the system works best when there have been at least five crime locations. These profilers feed that information into a data bank that also contains lists of suspects, police reports and motor vehicle records.
The computer processes that information using a complex mathematical algorithm to generate a "jeopardy surface" — a two-dimensional or three-dimensional map showing the suspect's likeliest location.
That often allows investigators to narrow their search from a 10-square-mile area to a few blocks.
"It will not tell you the person was 3 feet tall, had one arm, one leg and lived in the apartment in the back," says Philip MacLaren, vice president of Environmental Criminology Research in Vancouver, which sells software developed from Rossmo's research. Instead, he says, it helps investigators focus on a particular area.
Geographic profiling is not nearly as well known in this country as psychological profiling. In fact, Rossmo says that while Canada and Britain each have three investigators trained in that field, he is the only one in the USA with those skills.
As geographic profiling has become better known in the USA, Rossmo, 47, has been called in to help on dozens of cases that range from credit card fraud to murder.
His work helped solve the so-called Southside rapist case in Lafayette, La., where a series of burglary-rapes occurred in 1984 and 1995.
"A psychological profile is the who," he says. "A geographic profile is the where.""
http://usatoday30.usatoday.com/news/nation/2002-10-08-sniper-profile-1acover_x.htm
