Would you go into your local asylum and hand patients a gun? I should imagine the answer is a no.
Until there is a way to know the mental state of all Americans (impossible) then why allow guns? The case of this kid was he pinched his dad's weapons. You can't stop that happening unless guns are removed.
22 Mass shootings so far and it's not even half way through they year yet. That's a lot of innocent lives lost, not to mention all the gun related deaths from criminals, accidental, suicide... The problem with guns is that it's just too easy to kill many people very quickly. There is no place for guns within society in this day and age.