If you're worried about crime, buy a gun, even if its off the black market. Its the right of every free person to defend themselves, and besides that, gun ownership discourages tyranny, that's why governments try to squash gun-rights advocates.
However, if you have a gun that you're worried is going to start committing random acts of violence, PM me with the price you want to sell it for, and we'll work something out.
Adrian