A police officer, policeman or cop was an individual who worked for a law enforcement agency and was responsible for upholding the local laws. Police officers also investigated alleged violations of laws, arrested and interrogated suspects and protected local citizens.
In 1996, after a decades-long ordeal on 20th century Earth, a mentally confused Captain Braxton from the 29th century called a Los Angeles police officer a "quasi-Cardassian totalitarian." (VOY: "Future's End")
In 2004, police officers of the Detroit Police Department arrested Loomis after being tipped off by Jonathan Archer and T'Pol of his involvement in a series of local kidnappings. (ENT: "Carpenter Street")
Dan Bell was a fictional police officer portrayed in the The Big Good-Bye of the Dixon Hill series. In 2364, Jean-Luc Picard underwent an interrogation while playing Dixon Hill during a holonovel. (TNG: "The Big Goodbye")