Read this excellent piece from Arthur Chu in Salon. Here’s what I found to be the critical excerpt:

We barely know anything about the suspect in the Charleston, South Carolina, atrocity. We certainly don’t have testimony from a mental health professional responsible for his care that he suffered from any specific mental illness, or that he suffered from a mental illness at all.

We do have statistics showing that the vast majority of people who commit acts of violence do not have a diagnosis of mental illness and, conversely, people who have mental illness are far more likely to be the victims of violence than the perpetrators.

We know that the stigma of people who suffer from mental illness as scary, dangerous potential murderers hurts people every single day — it costs people relationships and jobs, it scares people away from seeking help who need it, it brings shame and fear down on the heads of people who already have it bad enough.