Tomorrow (April 16) is the first anniversary of the massacre/suicide at Virginia Tech. While moves have been made to restrict access to guns by the mentally disturbed, no other such moves have been made in Virginia. People like John Lott oppose such moves, arguing that allowing people to carry guns on campuses and in other public places reduces homicides (Lott has also been dumping on Obama for his supposedly bitter unhappiness with gun ownership). The data on that is a mixed bag, but another aspect of this is much clearer and a part of the VA Tech story, the very strong link between gun ownership rates and suicide rates within the US. It is just a lot easier to kill oneself if there are lots of guns around, and one does not have a chance to second guess one's intention.
I have done some digging around and guesstimate that if the US as a whole had the gun onwership rates one finds in the lowest states, we would see on the order of 10,000 fewer suicides per year in the US. That is more than the total killed on 9/11 or US military killed in Iraq. Here is a sources on suicide rates: http://www.suicidology.org/displaycommon.cfm?an=1&subarticlenbr=21. Here is a source on gun ownership: http://www.swivel.com/data_sets/show/100359. The five highest states in gun ownership are Wyoming, Montana, South Dakota, West Virginia, and Idaho. The highest states in suicide rates are Montana, Nevada, Alaska, New Mexico, and Wyoming. The five lowest states in gun ownership are D.C., New Jersey, New York, Rhode Island, and Massachusetts. The five lowest states in suicide rates are D.C., New Jersey, New York, Massachusetts, and Rhode Island.