What is Geographic Profiling?

Originally developed to help police locate serial killers, rapists and arsonists, geographic profiling can be applied to any circumstance where an unidentified person is known to have carried out activity at a series of geographic points.

The main tool in geographic profiling is a computer system called "Rigel." It is based on seven years of research in criminology, geography, forensic psychology, cognitive mapping, mathematical modeling, statistical analysis and investigative techniques by Detective Inspector Kim Rossmo, PhD, of the Vancouver Police Department. Rossmo developed the concept of Criminal Geographic Targeting (CGT). CGT is based on a complex algorithm that takes into account such mathematical principles as distance-decay functions, Manhattan distances (orthogonal distances measured along a street grid), and the relationship that exists between crime location sets and offender residence.

The research found that criminals—like all other humans—tend to follow patterns of movement around and through geographic areas. For example, people are more likely to carry out their routine activities close to home, work or school, or within a set distance from the commuting routes between these points (the principle of least effort). This activity space is related in predictable ways to where we live. As humans travel among their home, workplace and social activity sites, their activity space describes an awareness space that forms part of a larger mental map—an ‘image of the city’ built upon experience and knowledge. Within a person’s activity space there is usually an anchor point or base, the single most important place in their spatial life. For the vast majority, this anchor point is their residence. The Rigel system quickly carries out up to 1,000,000 mathematical calculations to produce the end result. Applied in hundreds of criminal cases around the world, it has proved to be highly accurate in both urban and rural settings.

In virtually any circumstance where an individual did something at a series of points that can be plotted on a map, geographic profiling can pinpoint the area of his/her residence. Any investigation seeking to locate an unknown person who is linked to a series of events - be it theft, fraud, arson, rape, murder or any criminal activity involving a series of locations - can benefit from the process. While there is no minimum number of sites necessary, it is generally preferred that there be at least five. Simply put, the more sites, the more precise the profile. This can be a series of five crimes or a single case involving five different sites. Any such series of locations allows the system to interpret the offender's "mental map" and calculate the most probable area of his anchor point - usually his residence.

Forensic Behavioural Analysis can assist in obtaining this service and contacting ECRI, the Vancouver company that markets the Rigel system and training in it's use. The Royal Canadian Mounted Police (RCMP) and the Ontario Provincial Police (OPP) in Canada, The Bureau of Alcohol, Tobacco, and Firearms (ATF) in the USA, and the National Crime Faculty (NCF) in England have all adopted the program as a new tool in combating serial crime.