Serpico (1973)

It follows the real-life story of Frank Serpico, an honest and principled New York City cop. As he delves into the police force, Serpico uncovers pervasive corruption among his colleagues. Determined to expose the truth, he faces increasing hostility and betrayal from within the department. Directed by Sidney Lumet and starring Al Pacino, the film is a gripping exploration of Serpico's fight for justice, moral integrity, and the personal sacrifices he endures in his quest to reform a corrupt system.