An understanding of where and why crimes occur can help prevent future crimes. Mapping crime can help law enforcement protect citizens more effectively. Simple maps that display the locations where crimes or concentrations of crimes have occurred can be used to help direct patrols to places they are most needed. Policymakers can use more complex maps to observe trends in criminal activity; such maps can prove invaluable in solving criminal cases. For example, detectives can use maps to better understand the hunting patterns of serial criminals and to hypothesize where these offenders might live.

Using maps to help people visualize the geographic aspects of crime, however, is not limited to law enforcement. NIJ is moving mapping technology into the corrections community, and mapping also can provide specific information on crime and criminal behavior to politicians, the press and the general public.