Bernard Harcourt is examining the relationship between institutionalizing the mentally ill and the overall homicide rate over at the Volokh Conspiracy. His first post contains a pretty amazing graph demonstrating correlation between the two. The second builds on the first.
It has also come to my attention that some states do not tie their mental health records into their firearms background check systems, nor do they support the FBI's attempts to do the same with the Federal system. I realize that they do this out of concern for the privacy of others. But that doesn't make it a good idea. If someone has been adjudicated to be a danger to themselves and others, then the public has a right to know. The public is "and others." I don't want crazy people or convicted criminals to have legal access to weaponry.
Wow me supporting a gun control measure, who'd have thunk it?