It seems to me a triple murder like that automatically disqualifies a place from being the friendliest on earth tho, especially when the context is 'an armed society is a polite society'.Dude came in from out of town to commit an armed robbery on a gun store where he killed three people. It's not like some argument on the range escalated into a mass shooting.
But I'm sure there are better examples to find anyway. I'm not hating on gun ranges, just saying there are friendlier places for sure.