Fueled by drug money and revenge, street gangs have flourished and spread across Southern California and beyond, thanks to sporadic and ineffective law enforcement efforts and inadequate intervention strategies. In the face of those tepid efforts, gang membership has exploded across Southern California since the 1960s. At the same time, gangs have grown more brutal _ engaging in a level of violence that holds many poor and minority communities in near constant terror. There are about 100,000 gangsters in more than 1,300 gangs in Los Angeles, Ventura and San Bernardino counties. They make up less than 1 percent of the...