Someone was creeping at work..felt uncomfortable..should I tell?

Long read.......So my job is very fast pace and requires your attention, it's also on a station that's boxed in on a platform. But it's open concept.

Well..sometimes when you're focused people sneak up on you, no biggie.

WELL..recently I had 30 mins left of my shift and out of the corner of my eye I noticed someone standing behind me to the side, just looking at me. They were at the next station over so there was space but they were just staring and as soon as he noticed I saw him he pretended to pick up trash on the floor. Like he had been standing there a while. I kept glancing at him because it startled me and kinda freaked me out. He eventually walked away, but then about 10 min later he came back and started to get closer to me right up to my station, "picking up trash" right there. I kept an eye on him and didn't turn my back to him. He then kept passing by till my shift ended. I was extremely uncomfortable. Shift changes can be a ghost town sometimes because by then all managers have left and so have most associates, so I asked someone to walk me to the time clock. I've never seen this person before but they may be from the other shift.

...my thing is; I've had people say farily inappropriate things at work before, job has all walks of life and I'm understanding to the fact some people may not be as knowledgeable on boundaries/different learning capibilties. So for this reason I'm not a stickler for tattle tailing when something's said, but if it does cross the NO NO line I do speak up with a verbal warning. However I've never had someone creep on me like this and not even say hey. It felt predatory like. And the audacity to GET CLOSER after you were caught the first time, makes it seem like he's a regular creep. I told 2 people at work and they just said "that's weird" but they didn't say if I should tell? Idk standing around isn't a crime..am I over reacting?