O.G.
Speaking of crime control, Mark Kleiman may have learned a lot about gang violence, but he has a thing or two left to learn about slang:
Sometimes indirect pressure is effective: in Lowell, Massachusetts, a wave of violence by Asian youth gangs was controlled by telling older figures linked with, but no longer active in, the gangs that if a gang engaged in deadly violence the gambling interests of that gang's OGs ("older guys") would be shut down.
Those are original gangstas where I come from.