11. A Web-Based GIS for Crime Mapping and Decision Support

Timely mapping of crime locations and accurate detection of spatial concentrations of crime help to identify where crimes concentrate in space and time and thus provide important information for crime reduction efforts of law enforcement. The main objective of this chapter is to design and implement a Web-based GIS for crime mapping and decision support. The prototype system allows users to detect and view crime hotspots in a Web environment in the form of thematic layers overlaid on background data. Four hotspot mapping techniques, i.e., choropleth mapping, grid mapping, spatial ellipse mapping, and kernel density mapping, are implemented. The system can be used for mapping crime hotspots, predicting the locations of future crime, and optimizing crime reduction efforts. It is a rich Internet application and is much more efficient than script-based clients in hotspot detection, map manipulation, and rendering. It is entirely based on open-source software, making it affordable for many small- and medium-sized police departments in developing countries. Results from the prototype development demonstrate that for a Web-based crime mapping and decision support system, rich Internet application technology in combination with open-source software is an effective solution in terms of both system performance and financial cost.