well Im all in favour of gun control, but one just has to look at a country like Switzerland, where everyone has to go through military service and by law has to keep a loaded automatic weapon at home (albeit under lock and key) and compare Switzerlands murder rate (almost zero)
with the US. It is much more a product of the culture, how we are raised what we are exposed to. In the typical American movie, problems are invariably solved with violence. That tells us something.
The US murder rate is something like 25times that of the UK.

BUt if one looks at other cultures, such as the Yanomami in south america who are very warlike, and encourage their kids (as soon as they walk) to go around and hit other kids with sticks. Their murder rate is 5000 times that of the US. Contrast that with the Kalahari bushmen who are the opposite, dont even spank their kids - its all cultural Im afraid.