The study hypothesizes that there are two basic motives that lead citizens to engage in preventive responses to crime: (1) citizens 'avoid risks' by engaging in such activities (risk avoidance is thought to be linked to fear of crime and victimization experiences) and (2) citizens become involved in anticrime activities, not because of any personal assessment of being at risk or because of past experiences with victimization, but rather as part of their participation with formal voluntary organizations in their community. These two dispositions may lead citizens to employ the same or different anticrime activities. Data were gathered through literature reviews; secondary analyses of 4 criminal justice survey data sets collected in the 1970's; 2 telephone surveys of residents in Chicago and Evanston, Ill.; a random telephone survey of 1,803 residents of the metropolitan Chicago area; interviews with leaders of community organizations in 3 cities; and a mail survey of 167 law enforcement agencies. Findings indicate that behavioral restrictions appeared to be the most prevalent response of citizens to prevent personal victimization, that measures taken to reduce unlawful entry were the most typical prevention measures taken to protect the home, and that a distinct set of anticrime efforts were taken by citizens to protect their neighborhood/community. The primary incentives for employing household-based protective measures are individual/private-minded ones (i.e., to protect property from loss and to protect the sanctity of the home). Moreover, territorial measures involving groups of neighbors in anticrime activity appear to stem from the workings of ongoing community organizations and not from spontaneous or informal voluntary action. In light of these findings, a revised conceptual framework is proposed and further research suggested. Overall, the research supports the notion that there are individual motives (risk-avoidance) and collective motives (social participation) that lead some citizens to become involved in anticrime measures. Results suggest that police and community organizations can play major roles in improving the quantity and quality of citizen crime prevention. Tabular data, footnotes, graphs, and about 80 references are included. Appendixes present literature review summaries and data collection instruments.