he didn't have to be 21 and was legal at twenty years of age. Being he was pretty young, it isn't unheqard of to be eligible...I think he can pretty much forget about being eligible to purchase firearms again though(however, I am not a legal expert & I could be wrong about this).
One thing is for sure(in my opinion), this guy will be on the streets again one way or the other and probably sooner than later. Unlike the aurora colorado gunman, things are different here. One needs to understand that...though scary...it is the way it is(sortof like how he was able to buy firearms in the first place(there is only so much 'someone' can do to prevent stuff)
"Damn the torpedoes, full speed ahead!" -Admiral Farragut @ Battle of Mobile Bay 05AUG1864