Twelve previously unpublished studies and reviews explore the impact of recent advances in crime mapping on crime prevention programs and criminological research. An introduction by editors David Weisburd and Tom McEwen traces the history of crime mapping and surveys the recent innovations that have brought crime mapping to the center of trends in crime prevention. The section on "Mapping as a Crime Prevention Tool" begins with Carolyn Rebecca Block's explication of the GeoArchive--a type of geographic information system--as a means of identifying problems and developing crime prevention strategies at the neighborhood level. Examples are drawn from the experiences of the Illinois Criminal Justice Information Authority. Faye S. Taxman and McEwen relate how police agencies have used geographic information systems to support interagency work groups on neighborhood crime prevention. Marc Buslik and Michael Maltz describe how the Chicago Police Department has reorganized its information system and changed its policies on information sharing in support of community policing. Lorraine Green Mazerolle et al. identify the challenges facing police departments that seek to launch computerized crime mapping systems, with examples from the Drug Market Analysis Program in Jersey City, NJ. Philip R. Canter explores the uses and possibilities of geographic information systems by police in Baltimore County (MD). The section on "Crime Mapping in Research" starts with a study by George F. Rengert and William V. Pelfrey contrasting the safety perceptions of community service recruits to actual crime levels of central Philadelphia (PA) communities. The mapping of gangs and gang violence in Boston (MA) based on the knowledge of police officers and other local crime experts is discussed by David M. Kennedy et al. Patricia L. and Paul J. Brantingham compare maps of violent crime in the cities of British Columbia (CAN) using 3 crime counts, rates and crime lo