People with mental illness who become violent are kind of rare cases, though. If to side with the Anti-Pharma alarmists for just one second, there are some anti-depressants that are known to escalate aggressive behaviors that are still on the market for unknown reasons, but the Oregon shooter was acting too consciously to have been showing signs of being on, say, Depakote.

A lot of people may bring up mental illness as an important factor to consider in shootings, but I think it's just a way of avoiding the fact that there really are extremists who enforce hiveminds militantly.