I found this about crime rate and CCW. Long, but good read Concealed Carry Permits Are Life Savers - HUMAN EVENTS
Here is a small part of it:
In research sponsored by the U.S. Department of Justice, in which almost 2,000 felons were interviewed, 34% of felons said they had been “scared off, shot at, wounded or captured by an armed victim" and 40% of these criminals admitted that they had been deterred from committing a crime out of fear that the potential victim was armed.
Allowing law-abiding people to arm themselves offers more than piece of mind for those individuals -- it pays off for everybody through lower crime rates. Statistics from the FBI’s Uniformed Crime Report of 2007 show that states with right-to-carry laws have a 30% lower homicide rate, 46% lower robbery, and 12% lower aggravated assault rate and a 22% lower overall violent crime rate than do states without such laws. That is why more and more states have passed right-to-carry laws over the past decade.