@ Sunny
I don't think he was mentally disturbed. He was maybe late 50s, dressed okay, kind of short, pot belly. When he spoke to me and then ranted a bit he sounded 'normal', per se. I guess it's one of those 'you had to be there' situations.
I think sometimes folks try to attach a diagnosis when there really isn't a condition (dementia, depression, mentally disturbed, etc.). I think when he said something about me going to hell, he was insulted and surprised that I had the nerve to call him out.
Footnote: A case could be made that I'm a bit more sensitive about creepy strangers due to the fact that I had a serious problem with a stalker (I don't use that term lightly) that went on for many years...had to involve police several times. I'm very aware of my surroundings and I tend to often project a "don't bother me" demeanor - or so I'm told.