The Ordnungspolizei or Order Police was one of the main apparatus for the security of Nazi Germany. During the 1930s, Heinrich Himmler, Head of the SS, along with the Commander-in-Chief of the Order Police, Kurt Daluege, totally reconstructed the police force of the Weimar Republic into a number of strong militarized formations. Those that served in this new police force were more than ready to carry out any order that the Nazi's required of them including persecution of Jews and anyone deemed inferior to the regime. In fact, in 1938, police units participated in the annexation of Austria and the occupation of Czechoslovakia. A year later when Germany invaded Poland, the role of the police changed forever. Police units were deployed alongside the German military including the special murder squads of the Einsatzgruppen. In Poland, Order Police were transformed into militarized police battalions and participated in combat operations which included carrying out security duties behind enemy lines. These duties were often sinister and alongside some Wehrmacht, Waffen-SS and Einsatzgruppen, the police battalions engaged in the systematic murder and annihilation of Poles and Jews.

Following the conquest of Poland the Nazi leadership created a massive recruitment drive conscripting more than 95,000 men in their thirties. Another 26,000 younger men were also recruited and indoctrinated into Nazi ideology and trained for combat. These new recruits would now take part not only in military operations but would be an integral part of the Holocaust, responsible for mass murders and guarding some of the Jewish ghettos. They would also assist in the destruction of the ghettos and helping in the transport of Jews to concentration camps. During the summer of 1941 these Police units were involved in mass killings of Babi Yar, Rumbula and Stanislaviv. Yet after the war, many of the Order Policemen claimed never to have been involved in Nazi crimes.