This study was designed to assess the effects of the activities of the Guardian Angels on citizens' fear of crime, incidence of crime, and police officers' perceptions of the Guardian Angels. The data, which were collected in several large American cities, provide information useful for evaluating the activities of the Guardian Angels from the perspectives of transit riders, residents, merchants, and police officers. Respondents who were transit riders were asked to provide information on their knowledge of and contacts with the Angels, attitudes toward the group, feelings of safety on public transit, victimization experience, and demographic characteristics. Police officers were asked about their knowledge of the Angels, attitudes toward the group, opinions regarding the benefits and effectiveness of the group, and law enforcement experiences. Data for residents and merchants include demographic characteristics, general problems in the neighborhood, opinions regarding crime problems, crime prevention activities, fear of crime, knowledge of the Angels, attitudes toward the group, and victimization experiences.