This strategy is based in the belief that violent crime can be significantly reduced when law enforcement, community members, and social services providers become partners in directly countering violent street groups and gangs. Successful and creative design and implementation of this strategy is shown in four case studies of relevant efforts in Boston, Chicago, Cincinnati, and Lowell (Massachusetts). The format for the presentation of the case studies shows how law enforcement partners identified the violent act that triggered their response; how the act was linked to a particular street group or gang; how active group members were identified for special enforcement attention; how creative levers and sanctions were designed and applied to make the response swift and meaningful; the outcomes that were achieved; and the lessons learned. Although some of the enforcement actions described might have been shaped by specific local conditions at the time of strategy implementation, the ideas, methods, and tactics used can be applied in other jurisdictions. A 7-item bibliography is provided.