Don't be to hard on the guy
Maybe he would be happier if those killed were just thrown out of windows instead of being shot. Guns don't kill people, people kill people. The USA has 20,000 gun laws on the books. None of which stop people from killing people.
One reason if you look back at world war 2, the only reason the Japanese didn't attack the US mainland was because they knew Americans all had guns. And if they relaxed the gun laws in Chicago and everyone was armed you would see the murder rate drop by a very large amount.