In each of these cases, the responsible parties had been identified and charged, and the legal process completed. Data were collected from written police interview reports, transcripts of court testimony, and all available police audio and video recordings with the 79 participants (shooters and others present before, during, and after the incidents). Three factors common to the incidents were identified: all perpetrators had committed other criminal activities, the gang's influence was significant in precipitating the shooting, and the shootings were unplanned crimes of opportunity, although all the perpetrators admitted to looking for trouble. Gang affiliation exerted a powerful influence because of the gang members' desire for excitement, the availability of weapons, group pressure, and the existence of ancillary confrontations. To prevent gang-related drive-by shootings, law enforcement agencies need to understand the nature of gangs and track the development of destructive gang relationships, devise an action plan to combat the problem, share resources and information across jurisdictions, and offer alternatives to juveniles at-risk for gang involvement. 12 notes