Police are units of civilian law enforcement. They can be a friendly or hostile faction, based on each mission.
Call of Duty: Modern Warfare 2
Zakhaev Airport Security
The first police faction to appear in the Call of Duty series. They were the first responders to the attack on Zakhaev Airport. They desperately tried to stop the massacre, but were quickly gunned down. Failing in putting a stop to the massacre, they called in the FSB.
Called in to stop Makarov's terrorist unit. This attempt failed, despite being well-armed.
Virginia Police Department
While not seen directly, their wrecked police cars litter the streets of Virginia.
Call of Duty: Black Ops
Havana Police Department
Called in after several Tropas members were killed by an undercover SOG unit and quickly arrived on scene, but are killed by Mason's SOG unit and Carlos' Cuban rebels. They're seen in the mission "Operation 40".
US Military Police
They escort Alex Mason, Jason Hudson, Robert McNamara, and an Unknown General to the Pentagon for Mason's meeting with John F. Kennedy. According to the unit patch on their left arm, they are from the 1st Cavalry Division. They are also zombies in the map Five.
Call of Duty: Modern Warfare 3
New York Police Department (NYPD)
New York Police Department cruisers are also present throughout New York City in the mission Black Tuesday.
Metropolitan Police Service
The territorial police force responsible for Greater London. Seen at the end of "Mind The Gap".
Zakhaev Airport Security
New Jersey Police Department
The NJPD are seen in the map Interchange.
Oasis Hotel Security Service
Is the civilian security service of Oasis Hotel and a corrupted security in the campaign mission"Dust to Dust"
Call of Duty: Black Ops II
Los Angeles Police Department
The LAPD are seen escorting Harper, David Mason, Jones, Samuels, Johnson, and the U.S. President in the beginning of "Cordis Die". They are also the only police force to have African-American members.
Federal Bureau of Investigation
Colossus Security Crew
Call of Duty: Ghosts
Austin Police Department
An APD cruiser is seen in the map Tremor.
Call of Duty: Advanced Warfare
San Francisco Police Department
Atlas Military Police
The Atlas Military Police are seen patrolling various areas around the Atlas HQ. Two officers are seen subduing Mitchell, llona and Gideon after they discover Irons' secret, and several appear in the Atlas Prison Camp.
Call of Duty: Black Ops III
The DLC map, Skyjacked is a police warship.
In the mission Vengeance, multiple Singapore policemen are seen, one corpse seen due to hanging and 2 others taking cover from a police car in a cutscene.