Wednesday, July 15, 2009

Mapping Murder

Having had a novel that followed the hunt for a serial killer published in May - where the geography of the murders was an important feature - it was kind of interesting to find a request from an academic journal, 'Crime Mapping', in my inbox this morning asking me to review an article concerning the geographical profiling of serial killers. It's not something that I've worked on myself but I'm familiar with the process as its largely built on the concept of cognitive maps. A cognitive map is the knowledge we each have about where places are in the world and which underpins how we make decisions about where to go and how to get there. I had a couple of books published on this subject a few years ago - Cognitive Mapping and The Cognition of Geographic Space.

The idea of geographic profiling is that there is a geographic logic to the places that a person commits their crimes. If you can unpick that logic you can start to determine where that person might live. And if you can marry that to the personality profile then you can significantly narrow the pool of people to sift through. In general, a criminal will commit crimes in places with which they are familiar, risking being identified against having an intimate knowledge of the victim, place, and routes in and out (giving a familiarity and confidence of the known). If a criminal commits a number of crimes there is a good chance that where they live is somewhere in the middle of the pattern. Unless of course they're a travelling criminal, but even then a pattern can emerge about what types of places they travel to and the pathways between those places that can give detectives some idea about where to concentrate their efforts. Whereas most detectives work on the premise that if they can identify the motive for a murder, they will be able to identify the criminal, geographical profiling works on the premise that motives are often indistinct and vague and its best to concentrate on the facts - the prime ones being where, when and who.

A leading expert on the subject is Prof. David Canter at Liverpool University who has a popular science book on the topic, Mapping Murder: Walking in Killers' Footsteps. He's worked on a number of murder and rape cases in the UK helping the police define their search strategy by trying to match it to the hunt strategy of the criminal - in other words to align their cognitive maps. Another pioneer has been Dr Kim Rossmo who worked as a Detective Inspector in charge of the Geographic Profiling Unit in Vancouver and founded a consultancy - Environmental Criminology Research Inc. - which produces specialist software for police forces and other agencies.

Anyway, it should be interesting to see what's presently going on in the field and it might throw up a few ideas to use in future stories.

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