This came on in the late 80s or early 90s. It originally was either a made for tv movie, mini series, or just a really long pilot.
It had to do with a spaceship that was a prison, something happened and some of the things got loose and escaped to Earth (maybe only one thing got to Earth). I believe it was in a special containment unit perhaps?
There was a guy that was tracking these thing(s) down, I don't remember if he was from the spaceship or not but I want to say no, and that he was helped with this woman who was a guard on the ship or something.
Does anyone know what I'm talking about?