Although people suffering from mental illnesses may statistically be more likely to be victims than perpetrators of violent acts, the disproportionate focus on the latter is not unwarranted.

People are afraid of unpredictability. They are afraid of irrational people doing irrational things, and many people with mental illnesses behave irrationally. That's the long and short of it.

That said, we ought to be careful in making ex post diagnoses of mental illness as a means of coming to terms with a tragedy. It is merely a figment of the collective imagination that a person of sound mind would not consciously take the lives of many others.