Do Me No Favors (2020)

An aging Hollywood actress and her lover plan to murder her rich husband and leave together. She is to set up the murder, he is to do it, and he will cover for them both, since he's an L.A. detective. However, when she sees an opportunity prior to the intended date for the crime, she commits the murder herself--seeing it as a favor to her lover--and arranges for it to look like suicide. Then she refuses to give her lover the money she's promised him for his expertise and for covering her tracks, since she was the one who killed her husband, not him. While they are arguing, she decides to tape their conversation so as to implicate him later if their relationship evaporates. He takes the murder weapon and kills her, with it still in the hand of the deceased producer so that only his fingerprints are on it. The detective makes out a report stating that the producer has killed his wife and then himself. But the maid comes in after the police have taken the body and the detective has cleaned up the scene of the crime -- and finds the tape with the argument on it.