There have been 155 homicides in Boston over 5 years, and 30 percent of these were committed by juveniles. The bulk of the homicides were committed with handguns, and the perpetrators were predominantly young African-Americans living in poor neighborhoods. Most of the handguns used by youth were new when obtained, and they were predominantly semiautomatics of five particular makes. The tracing of the handguns used in homicides has not revealed a major gun trafficking network, and there has been no major intervention in the supply side of handgun violence. The research has further shown that juvenile homicides and violence committed by juveniles tend to be gang-related, most often in the context of turf battles and retaliation for some perceived wrong. Most juveniles apprehended for gun-related violence have had numerous previous contacts with the justice system and are known to the police. Many were on probation at the time of their violent offenses. The intervention that has proven most effective has focused on deterrence. Boston police and Federal officers have saturated violence-prone communities with a law enforcement presence, message, and action that makes clear to youth that the violence must stop, or those individuals known to police will be targeted for investigation, arrest, and severe sanctioning. Through community meetings and personal contacts, the police and probation officers have made it clear that help is available for those who want to stop their violent behavior, but those who continue the violence will be targeted for sanctions. This intervention has been effective in reducing not only violence but crime in general. Questions and answers following the lecture are included in the video.