The Army Police usually called the Lanceiros, is the provost (military police)

Provost (military police)

Provosts are military police whose duties are policing solely within the Armed Forces, as opposed to Gendarmerie duties in the civilian population. However, many countries use their gendarmerie for provost duties....

 of the Portuguese Army

Portuguese Army

The Portuguese Army is the ground branch of the Portuguese Armed Forces which, in co-operation with other branches of the Portuguese military, is charged with the defence of Portugal...

 — being the speciality designated as Polícia Militar (Military Police) between 1953 and 1976. In the Portuguese Army it is a speciality of the Cavalry Arm, being the instruction and organization of the Army Police forces is of the responsibility of the Regimento de Lanceiros Nº 2

2nd Lancers Regiment

The 2nd Lancers Regiment is a unit of the Portuguese Army responsible for the instruction, organization and maintenance of the Polícia do Exército operational units.-History:...

(2nd Lancers Regiment).

The military police wear a black beret

Black beret

The black beret is a type of headgear commonly worn by armoured forces around the world including the British Army's Royal Tank Regiment , The Canadian Forces's Royal Canadian Armoured Corps , and The Australian Army's Royal Australian Armoured Corps among others...

.

Operational units of the Army Police:

• Army Police Group of the Army's Permanent Operational Force General Support Forces;
• Army Police platoons of the Mechanized Brigade, of the Rapid Reaction Brigade
  Portuguese Rapid Reaction Brigade
  The Brigada de Reacção Rápida , is a unit of the Portuguese Army which was known as BAI - Brigada Aerotransportada Independente until 2006...
  
  , of the Intervention Brigade, of the Military Zone of Azores and of the Military Zone of Madeira;
• Army Police platoon of the Military Prison;
• Army Police platoon of the School of Cavalry.