Investigation involves follow-up inquiry and activity on reported youth gang crimes; intelligence requires the development of background information on gangs and gang members for investigative purposes; suppression involves the targeting of youth gang leaders and other hard-core members for surveillance, arrest, and prosecution; community relations requires the reduction of circumstances under which youth gang crimes are likely to occur through community involvement, social intervention, and opportunity programs; and training and evaluation require specialized instruction in the police resonse to gangs and the evaluation of gang-related programs and activities. The discussion of multiple program strategies addresses planning, investigation, intelligence/investigative files, targeted gang suppression, community mobilization and opportunity provision, administrative leadership, and evaluation.