Once More, My Darling (1949)

Movie star Collier Laing is recalled to active duty with the Army Criminal Investigation Division. His mission: to sweep debutante Marita Connell off her feet and flush out her former boyfriend, who's sent her jewels stolen in occupied Germany. Soon it's a question of who's sweeping whom; Miss Connell's nickname is "Killer." But when she wants to elope, Laing begins to have qualms.