In my opinion the best course of action now is to make the gun rules stricter, currently the state with the strictest gun laws is California, but it's still way too easy to get the license over there. Introduce a rigorous process in place for people to get the license, including mental tests and regular medical check ups to prove that the person is still mentally there to own a gun every year or so.
People that say "just ban guns" I can understand why you'd say that and the frustration behind that. But in all honestly I think it's just too difficult to do that, for so many reasons. One, simply asking the millions of American people to give up their weapons whether they be legally or illegally obtained is a bit of a stretch, people can just hide them even if a law is passed to ban guns. The idea of having a gun for protection is something that's so engrained in the mindset of the American people, it would take a few generations to fully filter out the guns and that mindset. There are many other reasons that could be mentioned.
