This report presents interim findings of the Urban Institute's evaluation of the Gang Reduction Program (GRP), a $10 million, multi-year, federal initiative to reduce gang crime in Los Angeles, California; Milwaukee, Wisconsin; North Miami Beach, Florida; and Richmond, Virginia. The evaluation found substantial variation in collaboration levels among partners in each site, but each site achieved significant implementation successes. The effects of GRP in each site were mixed, and only one site, Los Angeles, showed a significant reduction in crime levels. By late 2007, however, three sites had undertaken significant steps towards sustaining GRP beyond the federal funding period.