One of my professors “Mr. Anderson” sat near Ted Bundy in a college course due to the proximity of their last names in alphabetical order. My grandmother in law had a store next to a serial killer from Montana (can’t remember his name now) but in both cases the people said they were just nice as could be. No suspicion of being a killer at all.
That’s what scares me the most, they aren’t the weird quiet kid. They’re the charming funny guys.