IM not particularly in favor of easy access to guns. But the causes are more cultural than simple availability of guns. If you look at a country like Switzerland - where by law citizen are required to keep a loaded military gun at home - there is very little gun violence.

Elliot Layton the man who studies murder

has some valid points about gun violence and violence in general.
(for instance the Yanomamo- have a murder rate 5000times the US,
they encourage their kids, from an early age 2-3 even, to hit each other
with sticks) and there are the Kalahari bushmen who are so nonviolent they are shocked that people would spank their children.

Its a terrible and sad day, I feel for all those families..