Einsatzgruppe

In general German military terminology, an Einsatzgruppe (plural Einsatzgruppen) is a temporary unit for a specific purpose, comparable to the English task force. Within the context of the Second World War and The Holocaust, they were mobile killing units that followed the armies invading the Soviet Union, ostensibly for rear area security and principally for killing Jews, Soviet officials, and other Nazi undesirables.

The genocidal groups, which killed approximately 2 million people, were organized in the summer of 1941, as part of the preparation for Operation Barbarossa. They all reported to the then head of the SS security organization, the RSHA, commanded by Reinhard Heydrich.

Organization
There were four main battalion-sized groups, and some smaller independent #insatzkommandos.

Operations
Their primary means of killing was by shooting and burial in mass graves. Different commanders had different ideas on the method of shooting; some insisted on machine guns so no individual had clear responsibility for killing, while others insisted that every unit member shoot at individual victims, to bond them to the effort. With either method, there was a high degree of stress on the units, with rampant alcoholism.