Background checks!
I mean if anyone would've found his posts and vids, no one would've give the twat a gun. 
ya know the irony of this "background check" is that the government attempts to do these things and then the population bitches and moans about their privacy. Then this occurs and the population wants these background checks to occur. But of course not on them, no no, they are law abiding citizens, the same as Mr. Rodger appeared to be. Just look at the Edward Snowden crap as a prime example, such a big ordeal.
Background checks for gun purchases look at your history in terms of the laws you broke, the civil documents received, military discharge stuff, and noted mental illnesses. If these things arent noted nor found because he didnt break the law, or wasnt presented as mentally ill, then i dont know what else you really want the government to do except literally spy and watch every civilian in the country to watch for supposed signs of mental illness, and then you begin to cross that boundary again about government spying.
Honestly i couldnt tell you where the line can be drawn, because my personal belief on the matter differs from anothers and those differences create this giant gray area that the law must attempt to fulfill and yet always fail at doing so, because you cant make everyone happy.
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thinking about it more, im almost more so inclined to say, blame the people who were close to him and knew of this, or blame the thousands who watched his videos prior to all of this and didnt say a damned word about any of this. I've been there for plenty of calls from concerned 3rd parties who just wanted a check up on a person they really didnt know due to a statement they wrote on facebook or something they overheard from a friend.(mostly due to suicidal thoughts, or threats of violence towards themselves or others)
