Today's NY Times has a column by Timothy Egan that purports to debunk the notion that more guns leads to less crime, which is John Lott's compelling thesis, updated periodically in new editions of his famous book (More Guns, Less Crime).
Mr. Egan cites a couple of studies, which I'll happily admit I haven't read more than the abstract. However, he also cites two anecdotes to support his case, both relating to the Tucson shooting earlier this month.
First, to support the notion that the armed citizen is more likely to shoot himself or another innocent bystander than the criminal, Mr. Egan cites Joseph Zamudio. Mr. Zamudio was carrying a pistol at the Safeway in Tucson when the shooting started. He rushed to the situation, prepared to shoot. However, facing a crowded scene, he decided that it was too risky to shoot, and waited for an opportunity to tackle the assailant.
There is no way to interpret Mr. Zamudio's behavior as supporting the case that an armed citizen is a dangerous citizen. If Mr. Zamudio had panicked and started shooting in the general direction of the fracas, adding to the bloodshed, one might have come to this conclusion. However, he thought clearly and acted with self-discipline. If the circumstances had been slightly different, e.g. if the assailant had been a few feet away from anyone else, Mr. Zamudio might well have been able to shoot him down - but that was not under Mr. Zamudio's control.
Being armed gave Mr. Zamudio more choice in how to react. Unarmed, he would have had a limited range of action.
Second, Mr. Egan disparages a proposed Arizona law that will allow faculty to bear arms on campus, which is currently outlawed. The example he cites is Arizona State University. As a public university, I suppose it is appropriate that the state make the rules governing ASU. However, in general, universities and other owners of private property should be free to make their own decisions about firearms possession, without state interference.
I should also note a compelling article supporting the notions that more guns equals less crime, and that the Tucson shooting was highly unique, by Gary Kleck in the Wall Street Journal ("Mass Killlings Aren't the Real Gun Problem," January 15, 2011).