Three types of enforcement strategies are reflected in the case studies presented: case-oriented drug law enforcement, network-oriented drug law enforcement, and comprehensive problem reduction strategies. Case-oriented drug law enforcement is essentially reactive and seeks sufficient evidence to arrest, prosecute, and convict drug distributors. Network-oriented drug law enforcement is a proactive effort in which distribution is traced from street-level drug sellers through mid-level and high-level distributors. This type of enforcement requires undercover and surveillance methods as well as complex financial investigations to build prosecutable interlocking cases. Comprehensive problem reduction strategies are proactive initiatives taken to reduce harm to the community resulting from both the supply and demand for drugs. They typically involve not only law enforcement agencies but also community members and relevant community agencies such as those providing education, health, and mental health services for high-risk populations involved in the problem. This report presents case studies of ongoing efforts that incorporate these approaches. Appendixes provide source materials from the study sites that readers can use or adapt to local needs as well as names and addresses of contacts for further information.