I have two points to make:

1) I understand people who have mental illness can have dark impulses, especially people with schizophrenia, like James Holmes, Adam Lanza, and the Oregon shooter. But the incidence of all mental illness around the world is the same. The same, I say. So why are mass shootings so much more common in the USA? Could it have anything to do with our lax gun laws? Anything to do with the 2nd amendment nutjobs?
2) Here’s a revelation: “If we were able to magically cure schizophrenia, bipolar disorder, and major depression, that would be wonderful, but overall violence would go down by only about four percent,” Dr. Jeffrey Swanson, a professor of psychiatry at Duke, told ProPublica last year. He notes a 2001 study of mass shooters that found three out of four had no psychiatric history.” This is from: http://www.newsweek.com/maybe-oregon-shooting-and-others-arent-about-mental-illness-378875
So although some people with mental illness do commit violent acts, the majority of them don’t. And stricter gun laws, hello NRA, would stop mass shootings right in the bud. When are we going to wake up to these much too numerous, tragic, wake up calls?