Aunque el documento sea para España, quizás una de éstas sea buena opción, ya que comunica la idea de una fuerza policiaca especial; pues, otra opción puede ser "policia especial" :-)

constabulary (ken-stàb´ye-lèr´ê) noun
plural constabularies
3. An armed police force organized like a military unit.

The American Heritage® Dictionary of the English Language, Third Edition copyright © 1992 by Houghton Mifflin Company. Electronic version licensed from INSO Corporation. All rights reserved.

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Note added at 31 mins (2006-10-20 18:28:18 GMT)
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Cambridgeshire Constabulary is the Home Office police force in England responsible for policing the ceremonial county of Cambridgeshire.

The force is divided into three basic command units (BCUs), these being Peterborough (Northern), Huntingdonshire (Central) and Cambridge (Southern). Force headquarters is situated at Hinchingbrooke Park on the outskirts of Huntingdon.
http://en.wikipedia.org/wiki/Cambridgeshire_Constabulary

Ya que no se trata de una fuerza policiaca nacional, sugiero "policia regional" para evitar las comparaciones entre lo que es un "county" (que puede comprender varias ciudades) y una "comunidad (autónoma)" (ya que encontrar divisiones políticas equivalentes puede ser muy difícil, si no imposible).