Law enforcement agencies are increasingly using social network analysis (SNA) to understand the organization of gangs and other criminal networks, to identify their relationships, and to analyze data that can be used to focus crime prevention efforts. This report details the implementation of a SNA program developed by the COPS Office in partnership with Yale University. Created as part of a violence prevention initiative in New Haven, Connecticut, the Project Longevity SNA program emphasizes the value of community collaboration when gathering critical information such as the location and membership of these groups. Noting that transparency and community involvement in data collection encourage community support, the report also describes the benefits of focused deterrence activities, thereby reducing arrests and increasing efficiency. In addition to a detailed introduction to SNA and the ways it can be adapted to community and law enforcement needs, this report provides examples of SNA strategies used in other cities and practical guidelines for implementation.