As early as 1938/39, special police formations euphemistically referred to as Special Operations Units [Einsatzgruppen] followed invading German troops into Austria, the Sudetenland, and (rump) Czechoslovakia. The precise nature and mission of these units became clear during the invasion of Poland in 1939: they were mobile killing squads tasked with liquidating alleged political and “racial” opponents of the Nazi regime. Whereas the brutal actions of mobile killing squads in Poland provoked isolated protest from Wehrmacht officers, the Wehrmacht and the squads worked together during Operation Barbarossa (i.e. the invasion of the Soviet Union) in 1941. This cooperation was regulated by directives made in consultation with SS leaders (Himmler and Heydrich) and orders issued by the High Commands of the Wehrmacht and the Army. The four mobile killing squads deployed by the Security Police [Sicherheitspolizei] and the Security Service [Sicherheitsdienst or SD] – Squads “A,” “B,” “C” and “D” – were supplemented by units from the Order Police [Ordnungspolizei] and the Waffen-SS. They were assigned not only to Germany’s three army groups, North (A), Center (B) and South (C), but also to the 11th Army (D). These mobile killing squads murdered Jews, Communists, prisoners of war (political commissars), Roma and Sinti, as well as the mentally ill, primarily in mass shootings, but later also in gas vans.

Between June 22, 1941, when Germany invaded the Soviet Union, and late 1941, at least 500,000 Jews were killed by mobile killing squads.

The photograph shows members of a mobile killing squad (probably C) killing Ukrainian Jews in Vinnytsia.