“Oakland, California,” intoned the narrator as the images flickered across the screen. “Nearly 10,000 gang members fight for control of these streets. The result: A war zone with a murder every three days.”The program was the second installment of a two-part documentary that aired in September. The first part had focused on African-American gangs in Oakland; this one explored Latino gangs and their territories by following the Oakland Police Department’s gang unit and the 9400 Boys, a small group in East Oakland. The conclusion of the show was the revelation that one of the 9400 Boys had been murdered; their leader, Javier, made a decision to...