Glamorizing violence / gun culture? Connected with drug trafficking? Gotta project a tough-guy image?
Evidently a couple of the people who were with him (and involved in the shooting) are now charged with gun crimes.
I don't know how to address illegal guns on the street (other than making laws tougher on legit gun owners isn't going to fix it). Only thing I can think of ... Dungeons. No more luxurious expensive jails for those people. You commit a crime with a gun, you get a one-way ticket to the dungeon. Every once in a while maybe someone will toss some food in over the wall. Whatever happens beyond that, happens. Only dead criminals come out, and probably sooner rather than later. No parole. No future. Never see your buddies again. You commit a crime with a gun, you are by definition a P O S undeserving of further life ... except that we don't have capital punishment, so the dungeon it is.