So when I was younger I would say maybe 7 or 8 my dad rented a movie and I'm trying to find it again. It was probably released in 80's or 90's, and I think the movie started with a group of cops being sent out to check something out (sorry about the vagueness I don't remember much about it) and the cops saw, either a creature that looked like a human or a human that just liked killing people, kill a group of men then runs off. They followed it and eventually wound up into a sewer system? (it could have also been a run down building and they went into basement) and started getting picked off one by one. I believe the last two people alive was a guy and girl who managed to kill the monster/human. The girl did somehow get chained up by the monster/human at the end.