How Does Geographic Profiling Work?
Mental Maps, 3D Images – Predicting Criminal Behavior
Feb 25, 2009
Geographic profiling works on the premise that the location of a crime site can provide the police with vital information. The geographic profile, which works in a similar way to a psychological profile, assesses and predicts the suspect’s most likely place of residence, place of work, social venues, and travel routes.
3D Images Called Crime Maps
Some people call these 3D images crime maps, but Kim Rossmo who developed geographic profiling, refers to the “hot spots” as jeopardy surfaces.
Although it may often seem so to the lay public, locations where crimes happen are not completely random, but often have a degree of underlying spatial structure.
Kim Rossmo Prefers At Least Five Crime Scenes
Rossmo prefers to have at least five crimes in a clearly linked series to analyze, or at least five crime scenes. From that, and from records such as suspect lists, police reports, and motor vehicle information, he enters information into his program and builds from there.
In the case of a serial rapist, for example, Rossmo used 79 of the more than 100 crime scenes and came up with a red dot on his computerized map that turned out to be the very spot to where the man lured his victims — his basement.
People are Creatures of Habit
When one thinks of it, people are creatures of habit and usually operate within their own comfort zones. That goes to follow that crimes tend to occur at locations where, in terms of profit and risk, offenders find suitable victims/targets.
What happens when a geographic profile is compiled, is that many aspects are taken into consideration including the daily movements of the criminal or suspect. Investigators collect as much evidence as they can about every minute of the persons day while the suspect travels between his home, workplace, and recreation places.
The result is an “activity space” (composed of these locations and their connecting paths) which forms part of a larger mental map—an "image of the city" built upon experience and knowledge.
Once the data are input into a software program a 2D or 3D image is created showing the most-probable locations of the center of activity, which will pinpoint the location of residence or crime to a very high level or probability.
Jeopardy Surfaces – Likely Area where Suspect Will Live
The patented criminal geographic targeting algorithm produces jeopardy surfaces, which are 3-D probability surfaces that indicate the most likely area where the suspect will live.
As Kim Rossmo points out: "By establishing the probability of the offender residing in various areas and displaying those results on a map, police efforts to apprehend criminals can be assisted. This information allows police departments to focus their investigative efforts, geographically prioritize suspects, and concentrate patrol efforts in those zones where the criminal predator is likely to be active".
Perceived Distance and Mental Maps
Two key elements in geographic profiling are, first, the idea that there is a difference between perceived distance and actual distance, and that certain things influence how this disparity can affect the commission of a crime i.e. availability of transport, roadworks, bridges.
And the second one is the concept of a mental map, which is cognitive image of one's surroundings that is developed through experiences, travel routes, reference points, and centers of activity – what we call a comfort zone. As criminals grow bolder their mental maps may change, but their usual activity will be within a certain range.
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