A sanctimonious and majestic police officer killed his mistress out of jealousy and insult, investigated the case as if nothing had happened, and later destroyed the evidence out of guilt. As he was not yet completely devoid of humanity, he admitted his guilt in front of a powerful witness. But all colleagues and officers prevented him from pleading guilty and "persuaded" him for the sake of his own interests. Inspired and educated by the public, he finally admitted his "innocence" and proved that he was an "unsuspected citizen". This is a famous Italian political film in the 1970s, which fiercely attacks the fascist political style and the crime and corruption within the police station, the technique is spicy and steady, the plot also has ups and downs, and the performance of the hero is even more unforgettable. This film won the Special jury Award and the Academy Award for Best Foreign language Film at the 1970 Cannes International Film Festival.