The Most Gentle Confessions(1971)

Original title: Les Aveux les plus doux

A sunny seaside town... Jean and Catherine are in love. They are young, beautiful, and poor. One of Jean's friends suggests he rob the cash box of a traveling circus. But the plan goes wrong: a circus employee is seriously injured, and Jean is arrested. He chooses to proclaim his innocence. To force him to confess and denounce his accomplice, the two detectives in charge of the investigation devise a Machiavellian plan...