as another poster Richard Corbeil pointed out on another thread "he doesn't have to give his son a background check to give him one of his guns."

So it's entirely possible that the guns are legal, Or at least were legal before the shootings went down. I know plenty of parents who have bought weapons (guns/rifles included) for their kids, including my step mother who used to buy my step-bro a plethora of weapons including nunchucks, swords, 2 rifles, a bow n arrows, some sai's (probably misspelling) and at least 10 to 15 hunting knives.  

It also doesn't have to be drugs/gangs.  15kids hang out outside on Lore n Meadow (because their parents obviously don't give a damn) Mainly just goofing off, doing dumb things but sometimes they end up fighting, (usually over a girl)  I can't imagine what would happen if a gun became involved tho it probably wouldn't be good.  I'd like to see parents actively parent & be accountable for their kids but good luck with that notion.