Two introductory chapters provide an overview of how community policing and problem solving have been used to address gang problems, with one chapter focusing on the role of police gang units in community policing. Five chapters present case studies of the strategies that five cities have used in applying problem solving approaches to gangs and youth violence. Operation Ceasefire in Boston was a problem solving initiative designed to address gun violence. Based on an analysis of the problem of youth gun violence in the city and the cooperation of criminal justice agencies, Operation Ceasefire focused on countering trafficking in illegal firearms and intensifying the police and prosecutorial responses to violent crimes by members of youth gangs. Through problem solving methods, the city of Indianapolis identified a link between violent crime and gangs and became a participant in the Anti-Gang Initiative of the U.S. Department of Justice, Office of Community Oriented Policing Services. A key element of this project was training all officers about gangs and gang identification. Further, through the creation of the Indianapolis Violence Reduction Partnership, a working group of criminal justice officials developed interventions that focused on the arrest and Federal prosecution of violent gang members. The Los Angeles' approach to youth and gang violence involved a modification of the Boston Ceasefire project. It consisted of both an intensification of law enforcement and court responses to violent crimes by youth gangs and the expansion of services and positive activities for youth in targeted neighborhoods. The approach to gang violence in Chicago focused on drug dealing and violence centered in multiunit dwellings. It involved the eliciting of the cooperation of building owners in efforts to rid their buildings of gangs and their activities of drug dealing and violence. A community near Seattle, Washington, used the expansion of services and leisure activities for youth as a means of diverting them from delinquent activity in the evenings and on weekends. Four chapters present case studies of suppression-based approaches to gangs and youth violence. The strategies profiled were implemented in St. Louis, Detroit, southern California, and Dallas. These strategies involved the targeting of gang activities for coordinated law enforcement efforts and the aggressive enforcement of curfew and truancy laws (Dallas). A concluding chapter focuses on the need to improve evaluations of gang-related strategies. Chapter references and notes