The mobile paramilitary units known as Einsatzgruppen murdered between one and two million Soviet Jewish and non-Jewish civilians under Nazi occupation. Contemporary and postwar documentation reveals that the units lumped together members of Germany’s various party and state security organizations, who, despite the common image of the Nazi “murder machine,” did not always work in complete collaboration. The article follows Einsatzkommando 12, a subunit of Einsatzgruppe D, which perpetrated executions in the southern regions of present-day Ukraine and Russia.