The police is the civil force organized by a government for law enforcement and the maintenance of public order. While they undergo combat training and are legally authorized to employ violence if necessary, they are distinct from the military in being a civil body entrusted only with domestic security.
Historically, this role was generally served by guards, soldiers that garrisoned within a city for its defense. Police, as a full-time civilian profession did not arise in the world until 1829, when necessity drove the United Kingdom to establish the Metropolitan Police Service. Nevertheless, by the French Revolution, France already had a force dedicated to the prevention and investigation of crimes whose development flourished under criminalist Eugène François Vidocq.
Civilizations throughout history also at times employed military forces whose mission revolved more around safeguarding the public peace or serving the common people. This included the Medjay of ancient Egypt, but a more draconian example was that of the Jinyiwei, secret police operated by the Ming dynasty of China which enforced the emperor's will against judicial rulings and purged dissenters under the pretense of preserving societal harmony.
The relationship between police and the Assassins can be complicated by the tendency of the latter to operate like vigilantes outside of the law in their quest to save humanity from the Templars. In one notable example, British police sergeant Frederick Abberline worked closely with Assassin twins Jacob and Evie Frye throughout 1868 in solving crimes and toppling the control of Templar Grand Master Crawford Starrick over London. However, the twins also founded a gang of their own, the Rooks, in their fight against Starrick's syndicate, the Blighters and were by all means an extrajudicial party.
In later years, Abberline felt morally conflicted over his past partnership with the Assassins, but in 1888, he enlisted the aid of Evie Frye once again to stop the serial killer and rogue Assassin Jack the Ripper. Ultimately after Evie killed the Ripper, in spite of his misgivings, he agreed to her request to safeguard the mass murderer's fate and identity so as to protect the Assassins as a friend.
- Though Arno Dorian helps police chief Charles Cochon de Lapparent solve crimes in Assassin's Creed: Unity, police do not appear as a distinct gameplay faction until Assassin's Creed: Syndicate. There, they are color-coded blue on the mini-map. Although players are not penalized for killing them in free-roam, in various story memories, doing so costs full synchronization.
- Assassin's Creed: Unity (first appearance)
- Assassin's Creed Chronicles: China (Mentioned only)
- Assassin's Creed: Syndicate