Dan got it. These are people issues, and you really can't fix those with rules, regulations, or guns.
Blackmouth: Fair enough on the analysis critique (though I did stop short of claiming any conclusive trends based on my insufficient analysis). My point is that it doesn't take a whole lot of questioning, based on proven trends (poverty rates vs. murder rates, e.g.), to bring a conclusion that those data mean more guns = less murder (Christ - I felt dumb just typing that equation) into question.
Are you not at least curious about what makes Japan and Singapore apparently immune to the "not enough guns" disease we suffer from so rampantly here in the US? I know you're supposed to leave out the extreme outliers in a typical trend analysis, but I think this is one case where the outliers might be the most meaningful and compelling data in the set. Whatever they're doing in Japan and Singapore to keep their idiots and crazies from killing each other is working really, really well, and I think the rest of the world might want to look into it.
There was a time when just about everyone in the US was armed. Anyone seen movies or read accounts of life in the Wild West? Guns were EVERYWHERE, and murder was, too....