Military police (MP) are police organizations connected with, or part of, the military of a state. The word can have different meanings in different countries, and may refer to:
The status of military police is usually prominently displayed on the helmet and/or on an armband, brassard, or arm or shoulder flash. In the Second World War, the military police of the German Army still used a metal gorget as an emblem.
Naval police are sometimes called "masters-at-arms".
In the Australian Army, the Royal Australian Corps of Military Police also performs the role of a secondary communications network in the front battle zone. In the Royal Australian Navy, the Naval Police Coxswain Branch performs dual roles of performing general police duties, investigation of criminal offences and a secondary role of ships' coxswain staff responsible for administration of ships' personnel. In the Royal Australian Air Force, the Royal Australian Air Force Security Police perform the military police role, and train military working dogs for the Royal Australian Air Force while the Royal Australian Corps of Military Police train their own working dogs for a more Infantry/combat role. All major crimes committed by or against personnel of the Australian Defence Force are investigated by the Australian Defence Force Investigative Service.
A police officer (also known as a policeman or policewoman, and constable in some forces, particularly in the United Kingdom and other Commonwealth nations) is a warranted employee of a police force. In the United States, "officer" is the formal name of the lowest police rank; in many other countries "officer" is a generic term not specifying a particular rank, and the lowest rank is often "constable". Police officers are generally charged with the apprehension of criminals and the prevention and detection of crime, and the maintenance of public order. Police officers may be sworn to an oath, and have the power to arrest people and detain them for a limited time, along with other duties and powers.
Some police officers may also be trained in special duties, such as counter-terrorism, surveillance, child protection, VIP protection, and investigation techniques into major crime, including fraud, rape, murder and drug trafficking.
Responsibilities of a police officer are varied, and may differ greatly from within one political context to another. Typical duties relate to keeping the peace, law enforcement, protection of people and property, and the investigation of crimes. Officers are expected to respond to a variety of situations that may arise while they are on duty. Rules and guidelines dictate how an officer should behave within the community, and in many contexts restrictions are placed on what the uniformed officer wears. In some countries, rules and procedures dictate that a police officer is obliged to intervene in a criminal incident, even if they are off-duty. Police officers in nearly all countries retain their lawful powers, while off duty.