A co-worker is looking for the name of a movie she saw years ago. She saw it in the mid 90s on a VHS recorded from TV so it is at least that old. The only scene she remembers is these 2 cops enter a sewer system chasing after a bad guy. However, this is no ordinary bad guy, he has the ability to change his victims appearances. He melds the 2 cops together. Any help on this would be appreciated!