Black Angel (1946) on Netflix

Plot summary

On the night Mavis Marlowe is killed, Kirk Bennett finds her body in her apartment, hears a prowler and loses him, and the ruby brooch pinned to her dress is gone. Picked up after he is seen leaving, Bennett says Mavis had been blackmailing him over their affair but cannot prove anyone else was there. He is convicted and sentenced to death for the murder. His wife Catherine has stayed loyal, and she begins her own investigation. A lead takes her to Martin Blair, an alcoholic composer and pianist whom Mavis, his ex-wife, had refused to let into her building that night. He had been locked in his own room, and the police had cleared him. Attracted to Catherine, Blair offers his help, telling her that Kirk was not the man he saw welcomed into Mavis's building.