Crime mapping is a law enforcement tool which allows personnel to represent crimes visually on a map or grid of a region. By organizing crimes this way, law enforcement personnel can identify patterns, areas of concern, and other information of interest which they can use in order to be more effective. Many urban police departments practice crime mapping, and it is common for such maps to be released to the general public so that citizens can stay informed about areas of concern and patterns of crime in their areas.
The concept of crime mapping began to emerge in the 1980s, when police stations started to radically rethink their approach to dealing with and preventing crime. Researchers seized upon the idea of representing crime statistics visually in a way which would be both accessible and useful, and they came up with the idea of crime mapping. At the same time, many police departments also began to adopt a community policing approach, empowering precincts with decision-making abilities rather than concentrating power in the higher ranks.
A basic crime map is simply a visual representation of the crimes which take place in a neighborhood. Different types of crimes may be color-coded, to make the map easier to read, and in areas where higher numbers of crimes are committed, the map may be brighter in color, or the marks used to indicate individual events may be made larger, to indicate that multiple crimes have taken place in a small region. Even a quick glance at the map can reveal all sorts of information, such as a marked increase in muggings in a certain area, or a steady pattern of assaults in another.
When police departments use crime mapping as a tool, they typically also integrate demographic and neighborhood information. In addition to displaying data about crime statistics, crime maps may also include things like the locations of schools, housing projects, playgrounds, parks, halfway houses, hospitals, clinics, and so forth, and businesses of interest like pawn shops may also be represented. Some crime maps also look at demographic data like average income, race, and so forth, allowing departments to generate even more data of interest for their neighborhoods.
While crime mapping might seem obvious and commonplace now, when most large communities make crime maps available to the public, it was revolutionary for its time. Crime maps allowed law enforcement to really see where the trouble areas in their neighborhoods were, and the maps could be used to schedule additional patrols and focus resources. Crime mapping is also used by social services to generate lists of areas which might benefit from additional interventions.