Gun control doesn't work...Shock! 

Oh looky here then

Fraser Institute : "During the past few decades, more than 25 states in the United States passed laws allowing responsible citizens to carry concealed handguns. In 2003, there are 35 states where citizens can get such a permit.

The upshot is that violent crime rates, and homicide rates in particular, have been falling in the United States. The drop in the American crime rate is even more impressive when compared with the rest of the world."