Please read "More Guns, Less Crime" by John Lott Jr.

In his book, he outlines how an increase in the presence of firearms leads to a decrease in crime. A side benefit of less crime is the fact that it will save the government money with reduced number of prossecutions and perhaps even a reduction in the number of law enforcement personel. That's not to say that all the bad guys will be getting shot, it means that the bad guys will stop commiting crimes due to the fear that their next intended victim may or may not be armed.

Also, I would like to point out that very few people actually do carry firearms on them. I myself have a concealed carry permit for the Commonwealth of Virginia, and I have never carried a gun on me outside of the house. I feel safe because I know I have a good, well funded police force out there... and also I feel safe because the criminals don't know if I'm one of those few people who actually does carry for self defense purposes.