It amazes me that whenever there is a massacre in USA nobody blames the fact that any nutter can buy a gun
I think it was the case that the guy who shot Congresswoman Giffords was too nutty to be allowed to plead to the charges days after the crime, but was judged perfectly sane* when buying the gun that he did it with, only days before.
*By who? I don't know - the store owner that sold the thing, I suppose. I think they're not allowed to sell guns to people who
appear to be nut-jobs.