When someone commits mass murder — as Dylann Roof just did in Charleston, or James Holmes in Aurora, or Adam Lanza in Newtown, etc., etc. — I don’t understand why there’s ever even a question about whether mental illness was involved. A man (usually), under no imminent threat, believes that the thing to do is to go to a place where people least expect violence, and to commit terrible acts of violence. Isn’t that inherently a sign of mental illness?
Maybe it would be better to ask what choices the person made before mental illness overcame them, and the extent to which they contributed to their own illness. But then the issue might get so complicated that it would be hard to parse verdicts cleanly in court, partly because then we’d have to admit a) how little we know about the causes of mental health and illness, b) how little we’ve learned since the advent of the medical model of treatment, which administers drugs we barely understand to people, not until health is restored, per se, but merely until their complaint improves, and c) how little we know about the influence of environmental factors, in a culture that is not always exemplary in sane values, wholesomeness or empathy.
Even so, I think that’s the better question to ask. And then all the consequent questions, too.