In researching murders with guns, I found a chart showing the rates of such murders per 100,000 inhabitants for the 50 states.  A sample:

_____________________

Iowa = .7

New Hampshire = .4

North Dakota =  .6

Vermont = .3

Wyoming = .9

______________________

District of Columbia = 16.5

Louisiana = 7.7

Maryland = 5.1

______________________

Gee whiz, I just can't figure out what would account for the low rates in the first five states, and the high rates for the second two states and D.C.    I mean, after all, it's not like the first five don't have hunting cultures and a lot of hunters with powerful guns.

What would explain Maryland having a rate that is 17 times higher than Vermont's rate?  Could it be explained by the fact that Vermont has maple syrup but Maryland doesn't?  Or what would explain D.C.'s rate being 41 times higher than New Hampshire's.  Could it be that D.C. has cherry blossoms and Congress but New Hampshire doesn't?

Maybe it's climate--maybe colder states have a lower rate of gun murders.  That would mean that when global warming turns these colder states into furnaces, their rates of gun murders will skyrocket.

I can't think of any other explanations.   Can you?

Incidentally, I haven't verified it, but I heard that Europe has had more mass murders than the USA over the last seven years, including the 77 killed in a mass shooting in 2011 at a political indoctrination camp in Norway, which has very restrictive gun laws.  

Regards,
Mencken's Ghost