civilian police CID. All British military police are correctly named as 'Service Police' and conform to the Service Police Codes of Practice (SPCoP). Powers for all arms of the British Service Police come from Armed Forces Act 2006, which came into force in 2008. The Military Corrective Training Centre—for all three services—at Colchester is operated by the Military Provost Staff Corps (MPS), an all-senior NCO corps which recruits only from serving personnel (but will liaise with other military and government sources where appropriate). MPS are not police and serve the same function as a prison officer. This role is additionally carried out by them on operations when handling foreign detainees at a main operating base such as Camp Bastion/Kandahar. United States The Military Police Corps maintains discipline and enforces the law in the United States Army. The Marine Corps has the United States Marine Corps Military Police, while personnel assigned to the Master-at-Arms branch fill the same role in the United States Navy (aided by temporary members of the Shore patrol). The United States Air Force is policed by the Security Forces, formerly called the Air Police and then the Security Police. Criminal investigation in the United States Armed Forces is carried out by separate agencies: The Naval Criminal Investigative Service (NCIS) (a civilian agency), the Air Force Office of Special Investigations (OSI), the Pentagon Force Protection Agency (PFPA), the Army Criminal Investigation Division (CID), the Coast Guard Investigative Service (CGIS), and the Marine Corps United States Marine Corps Criminal Investigation Division (USMCCID). The Defense Criminal Investigative Service (DCIS) is a civilian agency that answers directly to the DOD. The United States Constabulary was a gendarmerie force used to secure and patrol the American Zone of West Germany immediately after World War II. Vietnam In Vietnam, the 144th Brigade of Military Provost (Kiểm soát Quân sự) is under the command of the General Staff of the Vietnam People's Army. The provosts are responsible for guarding and protecting the Presidential Palace, government offices and army offices. They are also responsible for supervising military laws on soldiers and officers. Even though the 144th Brigade is the highest level division in the Military Provost force of Vietnam, there seems to be no unified command for the Military Provost under the General Staff, the Ministry of Defense or another General Department within the Ministry. There are several known military provost units such as the