SPI site evaluations have found that successful gun-violence reduction strategies 1) conduct advance problem analysis to identify "hot spots" for gun violence and the persons most likely to commit it; 2) target persistent gun-violence hot spots; 3) target prolific crime-involved individuals in hot spots; 4) use new technologies and advanced crime analysis; and 5) engage a wide range of collaborative partners. The SPI sites whose effective gun-violence innovations are profiled are Boston, MA; Kansas City, MO; Los Angeles, CA; New Haven, CT; and Rochester, NY. The Boston SPI addressed violent crime, particularly robberies and assault committed with guns, using community policing and problem-oriented policing Safe Streets Teams. The Kansas City SPI addressed gun violence using a model called the Kansas City No Violence Alliance to plan and launch a full range of interventions that included offender notification sessions, improved monitoring by patrol officers, strategic Federal prosecution, intensive probation, and parole supervision that included social services. The Los Angeles SPI addressed gun violence by targeting violent repeat offenders and gang members, using data analysis to identify and target locations and persons at high risk for gun violence, and using intelligence data to direct patrol, specific missions, and improved surveillance. New Haven addressed increasing violent crime and local shooting incidents in a persistently violent neighborhood. Rochester focused on intervening in retaliatory gun violence stemming from disputes.