The chapter presents the main concepts of the GeoArchive, a geographic database developed with the express purpose of providing police and the community with data that can facilitate problem-solving community policing. Based on the Illinois Criminal Justice Information Authority's experience in developing that innovative idea, many agencies are using a GeoArchive to identify problems and develop strategies for crime prevention and intervention at the neighborhood level. The chapter discusses the theory of the GeoArchive, offers practical suggestions and rules of thumb for developing a GeoArchive, and presents illustrative examples of how the GeoArchive is being used in current crime prevention strategies. The chapter also addresses a major problem in the development of computer mapping--data overload--and suggests methods for managing and analyzing vast quantities of information. Figures, notes, references