Frank Serpico, portrayed by Al Pacino, is seen bloodied and slumped in the backseat of a speeding police car, sirens wailing as he’s rushed to the hospital after a brutal gunshot wound to the face. The film unfolds his turbulent journey as a police officer beginning in 1960, where his passionate idealism drives him to favor non-violent methods for apprehending criminals. Distinctly principled, Frank resolutely stands against police corruption, particularly rejecting the culture of bribery that permeates the police force, which includes shakedowns and payoffs from illegal gambling and drug trafficking enterprises.
His unwavering stance isolates him, inciting suspicion from fellow officers who view his integrity as a threat. The tension escalates as Serpico navigates the counterculture of the 1960s, settling in the artistic haven of Greenwich Village, sporting long hair and a beard, which starkly contrasts the rigid police image. Aligning himself with a left-leaning social circle, he becomes increasingly alienated from the NYPD.
Despite his various attempts to address the rampant corruption by appealing to his superiors, he faces systemic indifference. With the assistance of a well-connected officer named Bob Blair, portrayed by Tony Roberts, Frank tries to combat the corruption; however, their efforts fall short against the entrenched bureaucratic resistance. The stress from his relentless campaign and the strife in his personal life culminate when his fiancée, Laurie, portrayed by Barbara Eda-Young, ultimately leaves him.
After gaining the support of a sympathetic police inspector who agrees to help him dismantle the gambling networks and expose the corruption to The New York Times, he is finally transferred to the narcotics division—his longstanding ambition. Yet, he soon realizes he’s entered an even more hostile environment where he has few allies and must contend with the animosity generated by his principled stance. This ultimately leads to a tragic turning point when he is shot in the face during a raid on a heroin lab, abandoned by the very colleagues he hoped could support him.
What follows is a harrowing recovery, as Serpico is tended to by family and a dwindling circle of friends, while also being targeted through anonymous hate mail. As the film nears its conclusion, Serpico bravely testifies before the Knapp Commission regarding police corruption. The narrative wraps up as he prepares to leave it all behind, waiting to board a ship. Despite being honored with a promotion to detective and recognized for his "conspicuous bravery in action" alongside the very officers who turned their backs on him, he decides to resign from the NYPD and seek a new life in Switzerland.
