Can't be delinked from gun ownership by any tom, dick and harry.
I have often thought that way. But guns are freely available in some Scandinavian country, I forget which. But nothing near the US murder rates. Granted it's probably still much much easier to get one in the US, including things like M16, AK47...
Then I thought it must be gang violence related in the inner cities. But even if you eliminate that, it's still significantly higher than other developed countries. You still have the Columbines, movie theater shootings, the ocassional mall attack, church attack, temple attack etc. in very nice pristine neghborhoods.
So it's not gun availability, and eliminating inner city gangs still leaves a surplus relative to OECD. I am thinking it's partially cultural and genetic. They value toughness over kindness. A testosterone culture. The US has never elected a woman to the WH for instance.