Fences That We Can Shoot Ourselves Off

I'm on the fence about "The Right to Bear Arms... or Not?" On one side I understand that if people were able to carry a weapon then maybe 9/11 could've been stopped or a multitude of events could have been averted. However, on the other side, I only believe that if I believe that everyone is good. I don't think that everyone has good aim or good control. Just because they have a permit doesn't mean they can shoot well, they might even add to the problem. As I talk about this law more and more I see myself side with the idea that letting people carry a weapon is dangerous, more harmful than helpful. I personally don't trust people and no matter what the state says even criminals can pass a test to lawfully carry a weapon, what's to stop them from causing crime and using the law of carrying a weapon in self defense? I also don't like the idea that it gives criminals the right to lawfully carry arms to protect themselves, yet it gives other citizens the right to protect themselves from criminals. I think that the right to carry would cause more problems than good. The thought of guns all around is scary.