To Catch a Thief

John Robie is a former jewel thief, formerly known as "The Cat", who now spends his time tending to his Rose garden in France. There is a series of jewel robberies on the Riviera that resemble his style and the police believe that the Cat is up to his old tricks again. A young lady vacationing in France suspects Robie at first, then offers to help him catch the burglar. (h/t Wikipedia)