The Assassin (1961)

The antiquarian Alfredo Martelli is brought to a police precinct without any explanation and interviewed by Inspector Palumbo. During the questioning, Martelli learns that his older wealthy mistress Adalgisa De Matteis was stabbed to death and he is the prime suspect. While in jail, Martelli recalls moments of his life with Adalgisa and his love affair with the young Nicoletta Nogaro.