He seemed to be a normal guy. It's pretty clear from the article that he was paranoid and vindictive to an extreme degree. A lot of people probably have violent, intrusive thoughts that they suppress, and it's a given that a few will act on them. His being fired from his job is probably what finally destabilized him.
Maybe we should pass a law that you can't be fired?
Maybe we can pass a law that everyone has to undergo mandatory periodic psychological evaluations?
Maybe we can fix it so, if you have paranoid and vindictive tendencies, you can be incarcerated for it or institutionalized?
Of course, you will think this is completely ridiculous, but isn't it the train of thought of the anti-gun pinheads? In fact, any one of these measures may have been just as effective as banning weapons. Or, they may have been just as ineffective. The guy seemed "normal" from all accounts. If the weapons he used had been unavailable, what's to say he couldn't have gone to Home Depot and bought the hardware to make a flame thrower? No matter what restriction you put in place, no matter how intrusive and cumbersome you make things, when a person goes off the deep end, there is little you can do to stop them.
Here's a thought.... Maybe if the guy had been raised in a family who instilled moral values and reverence for life... maybe if he had gone to a school where students paid respect to God... maybe if his entertainment world weren't inundated with extreme glorified violence... maybe if he had been taught from the time he was old enough to learn, about the Golden Rule?
Nahhh... I doubt any of that stuff would have made any difference here... let's just ban guns and continue to allow society to desensitize us to death through our movies and music, to trash God and religion, to attack decency and morality at every turn! Then when stuff like this happens, we can ponder what could have been done, like the idiots we are.