Question: In the film "Serpico", Frank Serpico, who was a former officer in the largest municipal police force in the United States, was played by which actor?

Context paragraphs:
Harpers Ferry Police Department: The Harpers Ferry Police Department, or HFPD, is the official municipal police force for Harpers Ferry, West Virginia.  HFPD also serves as the municipal police force for the adjoining town of Bolivar on contract.  The agency has three sworn full-time officers (including a K-9 officer), one sworn part-time officer, and one civilian employee.  The current Chief of Police is John D. Brown.

Policía Municipal de Ponce: The Policía Municipal de Ponce (English: Ponce Municipal Police) is the main police force for the municipality of Ponce, Puerto Rico, with jurisdiction in the entire municipality, including all 31 barrios of Ponce.  It was created under Law #19 of 12 May 1977, known as "Ley de la Guardia Municipal" (Municipal Guard Law) creating the municipal police forces in each municipality of Puerto Rico, and amended via Law #45 of 22 May 1996, known as "Ley de la Policia Municipal" (Municipal Police Law).

Kiev Police: The Main Department of Internal Affairs of the city of Kiev (Ukrainian: ГУМВС України в м.  Києві – Головне управління МВС України в м.  Києві ) was established in 1858 in Kiev as the "Kiev Municipal Police" (Київська міська поліція).  It is the largest municipal police force in Ukraine, with primary responsibilities in law enforcement and investigation in Ukrainian capital.  The Kiev Police is one of the oldest police departments in Ukraine.  Its headquarters are located at Volodymyr Street 15 in Kiev.

Serpico: Serpico is a 1973 American neo-noir crime drama film directed by Sidney Lumet, and starring Al Pacino.  Waldo Salt and Norman Wexler wrote the screenplay, adapting Peter Maas's biography of NYPD officer Frank Serpico, who went undercover to expose corruption in the police force.  Both Maas's book and the film cover 12 years, 1960 to 1972.

Carolina Police Department: The Carolina Police Department or Policia Municipal de Carolina is the main police force for the city of Carolina, Puerto Rico.  It was created under law #19 of May 12, 1977, known as "Ley de la Policia Municipal" (Municipal Police Law) creating the local police forces in each city of Puerto Rico.  It was one of the first municipal police forces in Puerto Rico.  Between late 1980 and late 2009, the department has become one of the fewest municipal police force in Puerto Rico with the largest number of officers, equipment and budget.  Since former mayor Jose Aponte de la Torre took office from 1988 unit his death in 2005, the police force has equipped with equipment, such as patrols equipped with weapons and cage, criminal information system and tactical bulletproof vests for its officers.

Toronto Police Service: The Toronto Police Service is the police force servicing Toronto, Ontario, Canada.  Established in 1834, it was the first municipal police service created in North America and one of the oldest police services in the English-speaking world.  It is the largest municipal police service in Canada and third largest police force in Canada after the Ontario Provincial Police and the Royal Canadian Mounted Police (RCMP).

Frank Serpico: Francesco Vincent Serpico (born April 14, 1936) is a former American New York City Police Department (NYPD) officer who holds both American and Italian citizenship.  He is known for whistleblowing on police corruption in the late 1960s and early 1970s, an act that prompted Mayor John V. Lindsay to appoint the landmark Knapp Commission to investigate the NYPD.  Much of Serpico's fame came after the release of the 1973 film "Serpico", which was based on the book by Peter Maas and which starred Al Pacino in the title role, for which Pacino was nominated for an Oscar.

New York City Police Department: The New York City Police Department (NYPD), officially the City of New York Police Department, is the largest municipal police force in the United States.  Established in 1845, the agency has primary responsibilities in law enforcement and investigation within the five boroughs of New York City.  The NYPD is one of the oldest police departments established in the U.S., tracing its roots back to the nineteenth century.

Charleston Police Department (West Virginia): The Charleston Police Department, or CPD, is the official municipal police force for the City of Charleston, West Virginia.  The Charleston Police Department is currently the second largest police department in the state of West Virginia, while being the largest municipal/city police department in the state.  As of 2008, Charleston Police currently has 184 sworn officers, 2 Animal Control Officers, and 29 civilian employees.  The Charleston Police Department has an organization of several different divisions, including a Patrol Division, Traffic Division, SWAT, Bicycle Unit, K-9 Unit, Community Policing & School Services Division, SEU or Special Enforcement Unit, and CID or Criminal Investigation Division.  The current Chief of Police is Brent Webster.

San Juan Police Department: The "Policia Municipal de San Juan" (San Juan Municipal Police or San Juan Police Department, in English) is the main police force for the city of San Juan, Puerto Rico, with jurisdiction only on the city limits of San Juan.  It is also the largest city police force in Puerto Rico, and the second largest police force in the island after of the Puerto Rico Police Department.  It was created in 1977 under law #19 of May 12, 1977, known as "Ley de la Policia Municipal" (Municipal Police Law) creating local police forces in each city of Puerto Rico .

Supporting paragraphs: Frank Serpico New York City Police Department
Answer: Al Pacino