Social institutions encompass a diverse range of groups and organizations, including families, friendship networks, clubs, and associations, that bring people together within communities. The distinctiveness of community crime prevention is its goal of altering the social structure of particular communities. Different crime prevention approaches have evolved which can best be understood as a succession of policy paradigms responding to urban conditions, such as community organizing, tenant involvement, resource mobilization, community defense (both intentional organizing and environmental modification), preserving order, and protecting vulnerable individuals. Crime prevention in high-crime areas presents particular difficulties for community approaches. These approaches have floundered due to insufficient understanding of the nature of social relations within residential areas and how community crime careers are shaped by the wider urban setting. 210 references and 1 table