Street gang violence is a concern for many inner cities. The National Gang Intelligence Center (NGIC) reported the existence of an estimated 33,000 gangs and 1.4 million gang members in the United States, mostly consisting of urban street gangs. ¹ More than 50 percent of state and local law enforcement agencies report that gang behavior exists within their local communities. Though previously thought of as an urban phenomenon, gangs have been expanding their influence into predominantly rural and suburban communities, including more than 400 gangs and 4,500 gang members believed to reside on tribal reservations.² Research shows more than half of all homicides in many major cities involve gang-related youth in possession of firearms.³ In some major U.S. cities, up to 80 percent of homicide offenders and 56 percent of homicide victims were under probation or parole supervision at the time of the crime.⁴ Researchers in Lowell, Massachusetts, for example, discovered 44 percent of homicide and gun assault offenders were under probation supervision at the time the homicide occurred.⁵