Of course it has something to do with gun control, he did not have any connections with IS as far as anyone is aware. In addition, as I said before, it is a lot harder to smuggle guns than it is it transfer money to someone so they can buy guns. If guns were not so available he would not have been able to acquire them so casually and he would not have been able to walk into a gay nightclub without much preplanning armed like he was able to.

Also @cowmeat, he was corrupted by Islam fundamentalists not simply Islam, I think its very important to make the distiction. IS is not a group of regular muslims.