In this article on GTA V using real gang members to do the voice acting.
"Of course, this would't be the first time a crime-fiction director or producer put those closest to their subject matter in front of a camera or behind a microphone. The Wire's David Simon famously cast a number of reformed Baltimore slingers, crooks and cops on his show, capturing a fascinating performance from Felicia "Snoop" Pearson, who sadly wound up going back to jail on drug charges after the show wrapped."
http://kotaku.com/gta-v-voice-cast-features-ultra-realistic-actual-gang-m-1245343364
"Of course, this would't be the first time a crime-fiction director or producer put those closest to their subject matter in front of a camera or behind a microphone. The Wire's David Simon famously cast a number of reformed Baltimore slingers, crooks and cops on his show, capturing a fascinating performance from Felicia "Snoop" Pearson, who sadly wound up going back to jail on drug charges after the show wrapped."
http://kotaku.com/gta-v-voice-cast-features-ultra-realistic-actual-gang-m-1245343364
