Bearing arms

Why does this sort of thing always seem to happen in the USA? I know bad stuff happens everywhere, but this phenomenon of Joe Bloggs gunning down random people seems to be distinctively American. It's hard to figure exactly why this is the case, and none of the explanations are very make you feel good about being American. One obvious explanation (certainly in the UK media) is America's prolific gun culture. We, resoundingly more than any other Western country, believe that the cost in bodies and dollars of gun crime is a reasonable price to pay for the right to own guns. Unfortunately I'm depressed, rather than hopeful that this latest tragedy will change many minds about just how high that price is.