He's a gang member. Did these rocket scientists consider that another member of the gang might have provided him with access to a firearm? If he can't be trusted to behave properly in public, he needs to remain incarcerated.
Drug gangs will always have guns. If all else fails, they'll smuggle them into the country disguised as a routine cocaine shipment. Or send some of their people into the armed forces and arrange for a truckload of M16s to get "lost"
With rampant identity theft, what's so hard about buying a gun using ID under somebody else's name? Or even just having your girlfriend buy for you?
If a guy is too dangerous to be allowed to buy a gun, then he's too dangerous to be out on the street