Wikipedia
The Hilfspolizei (abbreviated Hipo; literally: auxiliary police) was a short-lived auxiliary police force in Nazi Germany in 1933.
Hermann Göring, the innovative newly appointed Interior Minister of Prussia, established the Hilfspolizei on February 22, 1933 to assist regular police in maintaining order and in handling communists in the wake of the Reichstag fire. The organization quickly spread from Prussia to other German states and Hitler endorsed it in the Reichstag Fire Decree. The units were staffed mainly by members of Sturmabteilung (SA) and Allgemeine SS wearing SA or SS uniforms with a white brassard. It is estimated that the auxiliary units had 25,000 SA and 15,000 SS members. The units also included members of the Stahlhelm veteran organization ( Stahlhelm, Bund der Frontsoldaten). The force carried out or organized numerous violent attacks against Nazi opponents and staffed the early Columbia and Dachau concentration camps. The SS-Totenkopfverbände grew out of this formation. The force was disbanded in August 1933 due to international protests that the units violated the disarmament provisions of the Treaty of Versailles, Adolf Hitler's growing distrust of SA, and outliving its purpose during the consolidation of the new Nazi régime.
The term Hilfspolizei was also used for various military and paramilitary units set up during World War II in German-occupied Europe. In this context, the term often labels groups of local collaborators with the Nazi régime, such as the HIPO Corps in Denmark, various Schutzmannschaft units or Police Battalions, Waffen-SS divisions, Selbstschutz, etc.