Law Enforcement units and agencies are a part of the system, aimed to protect and uphold the law, provide federal and public security and even function as intelligence services.
1 Call of Duty 3
1.1 Feldgendarmerie
2 Call of Duty: Modern Warfare 2
2.1 Zakhaev Airport Security
2.2 FSB
2.3 Virginia State Police
3 Call of Duty: Black Ops
3.1 National Revolutionary Police Force
3.2 US Military Police
3.3 United States Secret Service
4 Call of Duty: Modern Warfare 3
4.1 New York Police Department
4.2 Metropolitan Police Service
4.3 Zakhaev Airport Security
4.4 New Jersey Police Department
4.5 Oasis Hotel Security Service
5 Call of Duty: Black Ops II
5.1 Los Angeles Police Department
5.2 Federal Bureau of Investigation
5.3 Alcatraz Guards
5.4 Colossus Security Crew
5.5 United States Secret Service
6 Call of Duty: Ghosts
6.1 Austin Police Department
7 Call of Duty: Advanced Warfare
7.1 San Francisco Police Department
7.2 Atlas Military Police
8 Call of Duty: Black Ops III
8.1 Indonesian National Police
8.2 Zürich Security Forces
8.3 Singapore Police
8.4 Morg City Police Department
8.5 US Military Police
9 Call of Duty: WWII
9.1 Gestapo
10 Call of Duty: Black Ops 4
10.1 South African Police
10.2 US Military Police
10.3 Alcatraz Guards
10.4 Los Angeles Police Department
10.5 Spanish Police
11 Call of Duty: Mobile
11.1 Los Angeles Police Department
11.2 Interpol
12 Call of Duty: Modern Warfare
12.1 Metropolitan Police Service
12.2 Russian Police
12.3 FSB
12.4 Kastovian Police
12.5 Balkan Police
13 Call of Duty Black Ops: Cold War
13.1 Miami Police Department
13.2 Soviet Police
13.3 Dutch National Police
13.4 East German Stasi and Volkspolizei
13.5 US Military Police Corps
14 Call of Duty: Modern Warfare II
14.1 United States Border Patrol
14.2 Texas Police
14.3 Mexican Federal Police
14.4 Dutch National Police Corps
14.5 Chicago Police Department
15 Call of Duty: Modern Warfare III
15.1 Urzikstan law enforcement
15.2 Kastovian Police
15.3 Zordaya Prison Complex Guards
15.4 Air Marshals
15.5 Specialist Firearms Officers
16 Call of Duty: Black Ops 6
16.1 United States Capitol Police
16.2 Avalon Police
17 Call of Duty: Modern Warfare 4
17.1 New York City Police Department
17.2 Paris Police Prefecture
Call of Duty 3[]
Feldgendarmerie[]
The Feldgendarmerie are encountered in the mission Hostage!, and are members of the military police unit.
Call of Duty: Modern Warfare 2[]
Zakhaev Airport Security[]
Source: https://callofduty.fandom.com/wiki/Law_Enforcement. This is an independent Call of Duty: Modern Warfare 4 reference page.