Fink verb – To give information (as to the authorities) about another's improper or unlawful activities. Reveal and fink are semantically related. In some cases you can use "Reveal" instead a verb "Fink". Nearby Word: finking
In Barton Fink, we never find out what Charlie does to get rid of Audrey's body, but the police find the headless body soon afterwards and reveal that he's really "Madman" Mundt, a wanted serial killer.
In Infinite, after Comstock realised that the Lutece twins were in a position to reveal Elizabeth's true origins due to the role they played in obtaining her in the first place, he had Fink murder them by sabotaging their Tear device in a staged accident.