In the mid-1960s in most states you could go to a gun store and buy an assault rifle no questions asked. Today if you wish to purchase any firearm the store must get permission from the FBI or its state counterpart.

Back in the mid-1960s there were few gun related massacres. So what has changed? A 2000 New York Times study of 100 rampage murderers found that 47 percent were mentally ill. According to a study released in July by the Treatment Advocacy Center the number of beds for the mentally ill per capita has plummeted to 1850 levels.

Steven P. Segal at the University of California Berkeley found that a third of the state-to-state variation in homicide rates was attributable to the strength or weakness of involuntary civil-commitment laws.

In the past many of the severely mentally ill would have been confined and cared for in a state institution. If we are serious about preventing mass murders we should embrace much greater funding for mental health, and strong laws for civil commitment of the violently mentally ill. Or we could do something useless and ban assault rifles and high capacity ammo clips.