Geographic Profiling in Criminal Investigation Analysis

Serial criminals show up infrequently, but when they do, they influence the local community to a great extent and put considerable pressure on local authorities for quick results. The crimes of a serial criminal, whether murderer, rapist or burglar, are not arbitrarily distributed. Geographic profiling is a statistical technique developed to determine the criminal’s most likely base of operations, based on the location and junctures of crimes. It enables authorities to prioritize suspects and allocate their forces more effectively. Geographic profiling constitutes a supplement of criminal profiling. While criminal profiling attempts to answer the “who”, geographic profiling tries to answer the “where”.

In this paper, I review the theoretical background behind the construction of a geographic profile and examine the fundamental assumptions on which the technique is founded. The method incorporates the concepts of distance decay and buffer zone in order to produce a scoring function for the offender’s anchor point. Distance decay expresses the assumption that the farther a criminal is from his anchor point or home base the less probable it is that he commits a crime. The buffer zone, on the other hand, describes an area that is too close to the offender’s home base where he will also avoid committing crimes.

Using access granted to ECRI’s software Rigel Workstation, a widely used professional geoprofiling platform that implements the technique, I explored its capabilities and functionality on two cases, one actual and one hypothetical, and observed the prioritization of locations the method provides in action.