In the real world, if somebody really wants to kill somebody they're going to find a way.
Of course, a gun does, however, make the job a lot easier.
I'm basically with Polnut on this. I've grown up in a culture where the idea of desiring gun ownership in most cases is largely considered weird and alien, and certainly not a God-given right that must never be infringed upon. Most Americans seem to find the prospect of not being able to carry a gun around to be a scary thought; I (and many Canadians), on the other hand, find the prospect of everyone carrying a gun around to be the scary thought. Most Americans seem to believe that the solution to crimes involving guns is for everyone to have a gun; I, on the other hand, believe that the problem is, rather, the underlying paranoid mentality of "everyone should be armed".
Given our backgrounds, we are unlikely to ever remotely see eye-to-eye on the issue.