Feldgendarmerie units, (also known as “Kettenhunde” or “Chain Dogs”) were generally given occupation duties in territories directly under the control of the Wehrmacht . Their duties policing the areas behind the front lines ranged from straightforward traffic control and population control to suppression and execution of partisans and the apprehension of enemy stragglers.
When combat units moved forward out of a region, the Feldgendarmerie role would formally end as control was then transferred to occupation authorities under the control of the Nazi Party and SS. But Feldgendarmerie units are known to have assisted the SS in committing war crimes in occupied areas. Felgendarmerie units took active part in Jews hunting operations, including in Western Europe.
But by 1943 as the tide of war changed for Nazi Germany, the Feldgendarmerie were given the task to maintain discipline in the Wehrmacht. Many ordinary soldiers deemed to be deserters were summarily executed by Feldgendarmerie units. This earned them the pejorative Kettenhunde, after the gorget they wore with their uniforms. The arbitrary and brutal policing of soldiers gave them the other nickname Heldenklauer, hero-snatcher, because they screened refugees and hospital transports for potential deserters with orders to kill suspected malingerers. Rear-echelon personnel would also be checked for passes that permitted them to be away from the front.
The Feldgendarmerie also administered the Strafbattalion, Penal Battalion, which were Wehrmacht punishment units created for soldiers convicted by court martial and sentenced to a deferred execution. During the final days of the war, as the Third Reich crumbled, recruits or soldiers who committed even the slightest infraction were sent to Strafbatallione.
The SS- Feldgendarmerie wore the same uniform and gorget as their Heer counterparts but had an addition cuff title indicating they were military police. Generally they conducted the same policing role, such as controlling rear areas but they also conducted counter-insurgency and extermination operations with einsatzgruppen against Jews, partisans and those deemed to be “enemies of the Reich”. These SS units had a severe reputation for being strict enforcers of military law. Nicknamed Kopf Jäger, Head Hunters, they also tracked down and punished those deemed to be deserters. From 1944 onwards, former members of the Ordnungspolizei serving with the Waffen SS , were also given military police powers and duties. These special SS-Feldgendarmerie were denoted by a diamond polizei-eagle insignia worn on the lower sleeve.