the biggest arguments used to justify citizens carrying a concealed gun legally is that they can stop a criminal in his tracks if he attacks you, prevent a criminal committing a crime against another citizen if you see it, deter criminals from doing crime as they don't know who is armed and who isn't.
the statistics and facts don't however bear the arguments out in any way.
so the laws allowing citizens to carry a concealed gun merely makes the presence of guns in public areas legal and has no deterrent or preventative effect whatsoever

