An officer of the law
The New York City Police Department was a law enforcement agency on Earth that existed during the 20th century. The function of the organization was to patrol and maintain order in New York City.
Often known by the initials "NYPD", the New York City Police Department employed police officers who had the power of arrest in the performance of their duties. In 1930, a New York City police officer attempted to arrest James T. Kirk and Spock for stealing clothes after the two had traveled back in time from the 23rd century. (TOS: "The City on the Edge of Forever")
Gary Seven once created a false identification stating he was a Lieutenant in the NYPD. The identification was among several Seven carried with him, others including a CIA and FBI identification. (TOS: "Assignment: Earth")
In a vision of Benjamin Sisko's, Benny Russell was beaten by Kevin Mulkahey and Burt Ryan, two officers of the NYPD. (DS9: "Far Beyond the Stars")
In an alternate timeline, Nazi forces occupied New York City and the streets were patrolled by SS security squads. The NYPD was not seen in this reality. (ENT: "Storm Front")