A couple things to think about
"Fewer than 5 percent of all calls dispatched to police are made soon enough for officers to stop a crime or arrest a suspect."
-"This Is 911...Please Hold", US News and World Report, June 17, 1996
"Gun control? It's the best thing you can do for crooks and gangsters. I want you to have nothing. If I'm a bad guy, I'm always gonna have a gun.
Safety locks? You will pull the trigger with a lock on, and I'll pull the trigger.
We'll see who wins." - Mafia enforcer Sammy "The Bull" Gravano, in an interview with Vanity Fair
All the statistics you could ever want, with citations, right here:
http://www.gunowners.org/sk0802.htm