A Leap in the Dark (1980)

Mauro, a judge, is worried about his older sister Marta, who took care of him since he was a boy, and is now affected by psychic problems and suicide fantasies. She seems to recover from her depression when Mauro acquaints her with Giovanni, a brilliant actor at the edge of legality. Mauro become unconsciously jealous of this relationship, and try to get Giovanni arrested...