The RMP exist in order to deploy, they are distinct from their civilian counterparts as they have unique operational tasks that have no equivalence in civil society. The RMP deploy as part of the field army, both at home and overseas, in support of the full spectrum of national and multi-national, joint, multi-agency conflict, conflict prevention and post conflict operations.

Whilst other agencies can, and do investigate crime committed by or against members of the Defence Department, it is the Service Police alone who have the unique capability to deliver the full range of policing functions, throughout the spectrum of conflict, at home and abroad. The policing capability required by the Army in the UK, Germany and other overseas Stations is provided by the RMP.

The RMP powers of arrest (in addition to those conferred on every civilian by civil and common law) are established within the Army Act of 1955, and can be exercised anywhere in the world, as service personnel are subject to English criminal law wherever they serve. The Act provides that a person subject to Military law, which includes all civil offences (Sect 70), found committing or alleged to have committed an offence against the Act may be arrested by a Provost Officer, or a person exercising authority under a Provost Officer. It also allows for a civilian to whom the act applies to be arrested and processed by the military police. These powers are extended to all service personnel by the Naval Discipline Act and the Air Force Act.

The RMP do not charge offenders, nor do they have responsibility for the prosecution process, they do not detain in custody and are not constables. When the RMP investigates a case, a series of reports will be produced to keep the chain of command informed of the process, allowing them to take any necessary action.

The policing skills utilised by the RMP in Station maintain the skills required on operations. Whilst the environment the RMP work within may change dramatically on deployment, the policing skills required are the same. There is an inextricable linkage between policing operations at home and on deployment, and all skills must be immediately transferable.

The investigations conducted on operations must be the same high standard as those conducted at home producing professionally complied case reports that show due regard to the laws of evidence and the Service Police Codes of practice. In high intensity conflict and on peace support operations the investigative procedure is the same; it is only the location that changes.

The Special Investigation Branch (SIB) of the RMP deploy along with the regular RMP companies across the globe, providing specialist investigative support to the Field Army. In high intensity conflict they continue to police, investigating a myriad of offences that range from murder to fratricide. The high profile nature of these investigations often draws great media and governmental attention. The SIB like all members of the Army work in all environments.

In addition to investigative support the RMP also have a distinct operational role to undertake. This is to regulate, to protect and to inform. The RMP on operations are enablers as they regulate the battlefield and move the Army forward and rearwards, in war and in support operations. Whilst some RMP companies are attached to the fighting Brigades others work in the complicated rear and divisional areas. The RMP are required to make sure the Army gets to where it needs to be.

Inextricably linked to this is the information provided to commanders. The RMP will advise on the use of routes, the movement of stragglers and refugees, and the movement of high profile Prisoners of War. They will also provide protection for high profile Military Commanders (Close Protection).

In post conflict operations the RMP role often expands, and they have historically found themselves as the only police force within a foreign country. In recent years (Kosovo and Iraq) they have found themselves as the only police force, required to police a foreign nation, and assist in the regeneration of the local Police Force.

The RMP role in a society where Law and Order has collapsed involves more than investigations, it requires the RMP to establish and train the Indigenous Police and in some cases completely rebuild a Police Force. Whilst the International communities provide civilian police officers to undertake this role in the latter stages, it is the RMP who are the first police on the ground post conflict. It is the RMP who have the soldierly and policing skills required to undertake this in very hostile situations. In Iraq the RMP are still heavily involved in this complex role.