We used to have two different police forces in Belgium.
The "Police" it self and the Gendarmerie.
The last one was stricter, and was more "military" styled then the police.
Police forces were more local minded, gendarmerie was less local.
So here is a well used example of a war time gendarme kepi.
Thise guy might have well helped Germans to find and deporte Jews and Belgian partisans during the war and after the war thise same guy might have imprisoned and executed Flemish or Walloon collaborators....
Thise type has been used untile the late 60' ties, in a different finish!