Blaming "the mentally ill" is a way of saying "not like me! I am normal!". Or a way of finding reason on unreasonable acts. And this happens overwhelmingly more when the mass murderer is white and middle class male. Because such guys can never commit acts of evil unless they are "mentally ill". I know many Autistics and some of them also have mental illness. They work, they go to college, they have families and they do have periods of their lives when they need more help. This whole conversation is making them even more afraid of disclosing the mental illness and be totally open, be activists for the community, because the retaliation is fast and ruthless. They might lose their kids, even though the kids were never in jeopardy; they do lose their jobs; they distrust doctors and avoid emergency rooms.
All this because we (general we) are too afraid of admitting that evil happens and fixated on our "freedom". Besides, Congress is moved by money, not personal stories, and the NRA has tons of money.
The solution becomes stripping all the rights disabled people have fought for, still fight for, and simply institutionalize everyone someone deems "dangerous". Owning a gun becomes more important than being able to walk free from place to place. And this thought is more mainstream than you think