Wow! I have a similar experience. I was doing some freelance bookkeeping back in my 20s, and I kept records for a fence installer in the Atlanta area for a few months. I quit working for him because he creeped me out especially in regard to how he treated his wife.
About 2 weeks after I quit, he showed up at my house “just to say hi”, which was bizarre. About a month after I quit, he was arrested and eventually convicted as a serial rapist. I was told by investigators (yes, I was questioned since I had been to his office), that all the receipts I had saved for his business had actually helped them place him at some of the crime scenes.
That was harrowing.
And no, no one who hired him had a clue.
A small handful of times I’ve been, as you said, creeped out by someone. When that happens, I get away as fast as I can. That creeped out feeling comes from a lifetime of dealing with people. The “feelings” are observations your subconscious is making that you may not be consciously aware of. They are based off a lifetime of your experience. Ignore them at your peril. BTW, this is where “prejudice” comes from. It really means pre-judged and it’s a survival mechanism. When I was in high school, I was knocked unconscious twice in what today is called the knockout game. Then it was just criminal assault. This is not something that’s part of white culture. It’s strictly a black thing. When I’m around black strangers in places like parking lots, my head is on a swivel. Prejudice is a way of staying alive.
That’s one of those too-close-for-comfort stories. Glad you never crossed him!