The 15-month data collection phase involved field research locales (Chicago, Philadelphia, and San Francisco) and a telephone survey of over 5,000 respondents. The study sought to understand what community and other groups are doing about crime, who participates in these collective responses, and the reasons for differences among communities' responses to crime. These diverse responses are classified under two broad categories: (1) a social problems approach in which the crime problem is seen as intricately enmeshed with other urban ills, leading groups to do something about the causes of crime; and (2) a victimization prevention approach, in which residents respond to crime through target hardening. Examples of each type of behavior are documented. An analysis of the characteristics of individuals who participate in these anticrime activities rejects the conventional wisdom that fear, estimates of risk, and concern about crime result in individual participation. Individual involvement in community groups is shown to be linked to affective ties to the neighborhood (social integration). Participation in anticrime activities follows as part of the appropriate and expected behavior of group members. The policy relevance of these findings is discussed in terms of the tactics presently being used at the Federal level to induce citizen participation in community anticrime programs. Finally, a community's capacity to undertake either a social problems approach or a victimization prevention approach is conceptualized as resulting from the organizational matrix of the community, other community resources, and the existence of citywide anticrime programs. A systemic model is presented and illustrated by a comparison of two communities with similar crime concerns but very different patterns of collective responses. Figures, tables, footnotes, an index, and a bibliography of about 90 references are provided. (Author summary modified)