The File on Thelma Jordon (1950)

Cleve Marshall is an assistant district attorney who falls for the shadowy Thelma Jordon. With her sordid past -- and her relationship with thief Tony Laredo kept secret from the married attorney, Jordon seduces the easily swayed Marshall, and uses him to cover up her misdeeds. When Jordon becomes the prime suspect for the murder of her wealthy aunt, she turns to Marshall, who goes to great lengths to clear her name.