Thousands of violent assaults, rapes, and murders are stopped due to armed citizens who happen to be there when something bad happens. There is some wepage related to FBI crime stats that report this. I know that if I were a mugger/rapist/murderer, I wouldn't want to risk having a .45 slug in my head. If anyone were stupid enough to risk it, oh well, the trash was taken out.
Before the ban, high priced "assault weapons" were rarely used in violent crimes, no gangbanger would ever spend $400+ on a "gat". After the ban passed, the guys in LA should have been proof enough when they used AK's that the ban doesn't disarm bad guys. I mean, they're criminals who don't obey the law or respect the law or life, so why do these blind voters think that somehow because "assault rifles" were made illegal, that all the bad guys would turn their stuff in. It perpetuates ignorance, disarms the people who respect laws and life, and does nothing to curb crime. All it does is give the feel good liberals a sense that they've done something, a placebo effect, when in reality they've done nothing constructive.
I used to live in a gang heavy neighborhood, plenty of stuff listed as banned and illegal there, but the owners of said items didn't seem to mind.