Everybody that has ever watched crime series or movies has probably seen the mapping of crime patterns in one form or the other. While Sherlock Holmes used red pins to mark the locations of a crime on a paper map, the sophisticated use of GIS can reveal more detailed, statistical crime patterns.

Some of the spatial patterns of crimes and offenders can be explained by environmental variables. Within environmental criminology, the influence of the environment on the offender is analysed. While socio-economic disadvantages may have an effect on offences such as theft, other crimes might in part be caused by the effects of environmental pollution on people. The detected patterns of crime can be used to fight and prevent crime. As crime prevention is the ultimate goal of any authority, understanding patterns and their possible causes helps to develop effective strategies and allocate appropriate resources to reduce crime.