This post initially appeared on Science Blogs

New York Times columnist David Brooks wants to explain away the actions of Jared Loughner, the gunman that shot 20 people at a political event as the isolated actions of a deranged psycho:

All of this evidence, which is easily accessible on the Internet, points to the possibility that Loughner may be suffering from a mental illness like schizophrenia. The vast majority of schizophrenics are not violent, and those that receive treatment are not violent. But as Dr. E. Fuller Torrey, a research psychiatrist, writes in his book, "The Insanity Offense," about 1 percent of the seriously mentally ill (or about 40,000 individuals) are violent. They account for about half the rampage murders in the United States[...]

Yet the early coverage and commentary of the Tucson massacre suppressed this evidence. The coverage and commentary shifted to an entirely different explanation: Loughner unleashed his rampage because he was incited by the violent rhetoric of the Tea Party, the anti-immigrant movement and Sarah Palin.

Seriously guys, it couldn't be that polarizing political lanscape or the incitements to violence, the REAL lesson says Brooks, is that we need a better mental health policy:

If the evidence continues as it has, the obvious questions are these: How can we more aggressively treat mentally ill people who are becoming increasingly disruptive? How can we prevent them from getting guns? Do we need to make involuntary treatment easier for authorities to invoke?

Never mind that there's not actually any evidence that Loughner was schizophrenic, and folks in the media like Brooks are woefully unqualified to make such claims based on a book list and a couple of youtube clips. It's easy to be convinced that Saturday's shooting spree was just the actions of a crazy person - it would be nice to be able to explain it away, and delude ourselves into thinking that if only we could lock schizophrenics up more easily, we'd all be safer.

But Vaughan Bell has a devastating critique of this sort of thinking in Slate, noting that the most complete scientific research on the effects of mental illness show very little increase in risk of violent behavior:

If that doesn't make sense to you, here's an analogy: Soccer hooligans are much more likely to be violent when they attend a match, but if you tell me that your friend has gone to a soccer match, I'll know nothing about how violent a person he is. Similarly, if you tell me your friend punched someone, the fact that he goes to soccer matches tells me nothing about what caused the confrontation. This puts recent speculation about the Arizona suspect in a distinctly different light: If you found evidence on the Web that Jared Lee Loughner or some other suspected killer was obsessed with soccer or football or hockey and suggested it might be an explanation for his crime, you'd be laughed at. But do the same with "schizophrenia" and people nod in solemn agreement.

He ends by noting that violence by the mentally ill is often over reported, and presented with a false perception of risk (seems like a recipe for a robust positive feedback loop). We may never know what caused this young man to walk into a crowd and start shooting. But we should use it to have a serious conversation about violent political rhetoric. We should use it to have a serious conversation about gun control. We should even use it to have a serious conversation about mental illness. What we should not do is say, "Oh, he was crazy," and move on.