I can see no reason that anyone should be permitted to own handguns or automatic weapons. If you want to cite the The 2nd Amendment, perhaps you could only allow the weapons that were manufactured in those days. As to "providing civilians with military-grade arms", we know that isn't going to happen.

Guest gun owner - I too, dislike SSRI drugs but what proof do you have that Cho was taking drugs? As far as I'm concerned, he should have been heavily medicated and/or institutionalized. Teachers see these 'walking time bombs' all the time. What can you do if the parents won't co-operate?