One of the big problems with guns in the U.S. is the inability to come up with an accurate way to identify who shouldn't have them. It would be great if we could look at people and reliably conclude "Future school shooter" or "obviously gets shitty drunk on Pearl Beer and leaves loaded guns out in a house full of kids." Since this is impossible, we have to rely on proxy variables that our friends at the NRA are all too eager to remind us are imperfect. Plenty of people planning to commit crimes with guns have none of the red flags (felonies, psychiatric diagnoses) that our flimsy system of background checks is designed to catch.
My suggestion for reducing gun violence is to wait until concealed carry becomes legal in a given jurisdiction and then automatically reject the first 100-1000 applications. Because you know who society doesn't need running around armed? The guy who has been waiting his entire life to pack heat. He's so excited that he sprints down to the police station the first day concealed carry is allowed, not unlike a starry-eyed tween ecstatically racing to get One Direction tickets, to get his permit. The guy who simply cannot wait to be carrying a gun is precisely who we should be worried about.
Of course that is a half-kidding suggestion and no such system would be legal or workable. But there's a different group of people we really, really need to worry about being armed: people who want George Zimmerman's autograph. You know they're all gun owners. Most of them probably do concealed carry if they can qualify for the permit. They have guns and they're excited to have a chance to meet a guy who is famous because he shot a black teenager. Maybe shake his hand and congratulate him. Some of them brought their kids.
The folks over at Sociological Images, providers of the link, try to break down the psychology of someone who would actually put George Zimmerman on a pedestal (tl;dr – essentially a bad case of Just World Phenomenon in which everyone deserves whatever happens to them). It would be great, though, if we could take Zimmerman around the country and somehow mark the people who go out of their way to meet him, shake his hand, and ask for an autograph. Perhaps an invisible dye would do the trick, but I'm agnostic about the method. Assuming we can't pass any laws precluding them from owning guns, it would nonetheless be fascinating to see how much Ground-Standing and "self defense" shooting they end up involved with as a cohort.
It's not about what Zimmerman did – it's about the fantasy of one day doing the same. And that's terrifying.