Slightly Scarlet (1956)

"Out of the shadows of a vice-ridden city comes James M. Cain's most explosive drama!"

Kleptomaniac Dorothy Lyons is paroled from prison into the custody of her sister June, secretary to "reform" politician Frank Jansen. Ben Grace, associate of crime boss Sol "Solly" Caspar, sees this as a way to smear Jansen's campaign. Seductive Dorothy will do anything to get what she wants, which includes having a good time with Ben-- whom June is now in love with.