It's hard to imagine, but Serpico presents itself as the story of an honest police officer. Sidney Lumet directed this film, which was written by Waldo Salt and Norman Wexler based on Peter Maas’ biography about NYPD officer Frank Serpico, who challenged widespread corruption within the department. Al Pacino leads the cast, alongside John Randolph, Jack Kehoe, Biff McGuire, Bernard Barrow, Nathan George, and Tony Roberts. The score features music from Mikis Theodorakis and Giacomo Puccini, with cinematography by Arthur J. Ornitz. Lumet’s film delivers powerful storytelling combined with outstanding performances. Frank Serpico (Pacino) is a figure of legend to those who live on the streets, but he was deeply disliked within the NYPD—so much so that his commitment to doing what's right nearly cost him everything. The movie traces Frank’s entry into the police force and then shows how corruption develops around him. Throughout, we also see aspects of his personal life, his relationships outside of work; Lumet and Pacino make it clear that Frank isn’t portrayed as a flawless hero—he has imperfections like anyone else. New York City is depicted vividly as a gritty place, the constant activity irritating, and the dark side where criminals and corrupt officers operate leaves you feeling unclean. It serves as both an engaging look at a character and a disturbing unveiling of what was happening, ultimately becoming a moving experience as the story reaches its end. Excellent. 9/10

Source on TMDB