Skip to main content
CNN Europe CNN Asia
On CNN TV Transcripts Headline News CNN International About Preferences
powered by Yahoo!

Computer profiler aids in sniper hunt

By Jeordan Legon (CNN)

Police Foundation Director Kim Rossmo says geographic profiling
Police Foundation Director Kim Rossmo says geographic profiling "provides an optimal search strategy."

   Story Tools

• Interactive: The death penalty
• Interactive: Police close in
• Interactive: Suspects' trail
• Story: D.C. area victims

(CNN) -- Software is leading the way for investigators trying to pinpoint a Washington-area sniper.

Geographic profiling, developed by former Vancouver, British Columbia, police detective Kim Rossmo, tries to zero in on the suspect by using computers to track the mass of data flooding investigators' desks -- location, dates and times of crimes. The program then matches the information with what criminologists know about human nature.

Rossmo told reporters his software can help police determine where a suspect lives within half a mile.

"In effect, it provides an optimal search strategy," Rossmo said.

Rossmo, director of the Washington-based Police Foundation, started assisting investigators in the sniper case last week.

Calculating the path

His software, which was developed by a commercial vendor and named Rigel, carries out millions of mathematical equations to give investigators a better sense of a killer's "hunting area" and where he is likely to live.

Rossmo said he relies on what psychologists term the "least-effort" theory. Crimes typically happen "fairly close to an offender's home but not too close," he said.

"At some point, for a given offender, their desire for anonymity balances their desire to operate in their comfort zone," he said.

Rossmo's system has been used by Scotland Yard, the FBI, the Royal Canadian Mounted Police and dozens of police agencies worldwide. Rossmo developed it while walking the beat in Canada and reading widely -- including a book on the hunting patterns of African lions. The geo-profiling technology was his doctoral thesis.

Methods help solve serial murders

Geo-profilers claim their methods have helped detectives solve about half of the 450 cases they've studied -- everything from serial rapes to serial murders.

"It's the high-tech version of the pin map," said Richard Bennett, a professor of justice at American University. "The concept is simple. But you can put a lot more information in. ... It's what you do with the information that is key."

Bennett said nothing takes the place of good, old-fashioned detective work but computerized geo-mapping techniques help.

"The advantage is you're using computer science and computer analytic abilities to solve a crime," he said. " You don't have a big city police chief out there who isn't using some form of this mapping."

Story Tools

Top Stories
Burgers, lattes and CD burners
Top Stories
CNN/Money: Security alert issued for 40 million credit cards
© 2004 Cable News Network LP, LLLP.
A Time Warner Company. All Rights Reserved.
Terms under which this service is provided to you.
Read our privacy guidelines. Contact us.
external link
All external sites will open in a new browser. does not endorse external sites.