1941 May, EINSATZGRUPPEN (Mobile Killing Units) (Germany)
Was officially established by Heydrich and army quartermaster Wagner. Although there were killing squads which operated in Poland as early as September 1939, the Einsatzgruppen was put into place in preparation for the attack on Russia which concluded the agreement between the Army and the SS as to the division of responsibilities. These mobile killing units consisted of about 3000 men. Most of them were professionals, including many lawyers and professional soldiers. There were even doctors and an opera singer. Each of the four main groups were assigned a different sector from north to south moving with the troops east. "A" moved into the northern sector and the Baltic states, "B" went through Bialystok and Vitbesk toward Moscow. "C" through Zhitomir, Kiev, and Krakow and "D" moved into the southern sector through Kaminetz, Odessa, and up to Stalingrad.