We hear ad nauseam that more-enlightened countries around the world have lower homicide rates than the US because they have fewer firearms in private hands. This is repeated so often that a great many people simply believe it to be true. The correlation, however, actually goes the other way, as I demonstrated in this post from 2015.
I’ve just run across an article from 2014 that looks at the numbers in considerable detail (including a helpful Excel file you can download). Read it here.