Gun laws are only as strong as the weakest link. Houser had domestic violence history, had a history of destructive crime, had been involuntarily committed, had been denied a conceal carry permit, and he still legally purchased a gun at an Alabama pawn shop which he used to kill two people in a different state. What is increasing is the ability of people like Houser and Roof and those before them to find like-minded individuals on stormfront, 4chan, reddit, or wherever else who post violent reactionary rhetoric that encourages them. Certain media influences are getting increasingly ridiculous, and ultra-conservative political groupies stopped pretending to be reasonable a while back. These cultural influences are what these folks are stewing in. Better medical care would surely help, if these people weren't convinced to turn it down or opt out of it.