This is literally the premise of Fallen. Washington plays homicide detective John Hobbes, who battles an unseen evil force which passes from human to human by touch and takes over its host to do its bidding.

Hobbes has been tagged by the demon through one of its bodies belonging to serial killer Edgar Reese (Elias Koteas). Hobbes nabbed Reese and is there to witness his collar’s last breaths – used in part to sing the Rolling Stones’ “Time Is On My Side” – in the gas chamber. Hobbes is nonchalant about Reese’s passing that night and boasts that he looked good being interviewed on no less than four channels. But Hobbes’ peace of mind is soon disturbed when he begins to investigate new murders that look exactly like Reese’s dirty work.

These are no ordinary copycat murders. Whoever is doing them knows more than the average television viewer. It appears to be an inside job and all clues increasingly point to Hobbes. The killer leaves little hints, writings on walls and on his victims. Hobbes pieces these marks together, leading him to Gretta Milano (Embeth Davidtz), an expert on angels and the daughter of a respected cop who 30 years earlier fell victim to this same demon. So Hobbes knows who the killer is, but he doesn’t know what form he’ll take or how to prevent him from coming in contact with his family, his friends, or even himself.