From Thomas Sowell's latest column:
Amid all the heated, emotional advocacy of gun control, have you ever heard even one person present convincing hard evidence that tighter gun-control laws have in fact reduced murders? ...
What almost no one talks about is that guns are used to defend lives as well as to take lives. In fact, many of the horrific killings that we see in the media were brought to an end when someone else with a gun showed up and put a stop to the slaughter. The Cato Institute estimates that there are upwards of 100,000 defensive uses of guns per year. Preventing law-abiding citizens from defending themselves can cost far more lives than are lost in the shooting episodes that the media publicize. The lives saved by guns are no less precious just because the media pay no attention to them.
Read the whole thing. Go here for the Cato research that Mr. Sowell is talking about.