Know how to spot an ax-wielding door-hacker

Sometimes you get introduced to someone and every word that comes out of his mouth is very friendly and nice and normal and he's smiling and nothing specific about what he's doing is weird, but he's totally giving you the heebeejeebies and you're thinking "why do I get the feeling that you might kinda be a crazy sociopathic murderer who would hack down someone's door with an ax and I really don't want to make you mad?" 

 

Yep, that happened to me today.

Then sometimes you have a really nice conversation with someone and you're really enjoying talking to them because they seem smart and funny and nice and normal and you instantly become friendly and then he gets a little too comfortable and offhandedly mentions that he actually did hack down a girl's door with an ax once....

Yep.  That happened to me too.

 

Moral of this story?  I clearly don't know how to spot an ax murderer.