In 1939, Oberhauser was assigned to Reichsarbeitsgemeinschaft für Heil- und Pflegeanstalten, part of the office for Action T4 and one of several front organizations of Hitler's Chancellery, in November 1939. This organization was responsible for the killing of approximately 100,000 mentally ill and disabled people during Action T4. At the killing centers of Grafeneck, Brandenburg and Bernburg, where these people were murdered en masse by gas, Oberhauser was a Brenner, or Leichenbrenner : he was responsible for the burning of the bodies in the specially installed crematory ovens.
Operation Reinhard
After finishing Action T4 in August 1941, in November Oberhauser was transferred to the staff of the SS and Police Leader for the Lublin district, SS-BrigadeführerOdilo Globocnik, to take part in Operation Reinhard, the extermination of Poland's three million Jews. From November 1941 until 1 August 1942, Oberhauser was posted to Bełżec extermination camp as the leader of a guard platoon. He first visited Bełżec in the fall of 1941, before the extermination camp existed, to remove military equipment at the site. He was responsible for the development of the camp. In December 1941, Oberhauser returned to Bełżec with construction materials and a team of Ukrainian Trawnikis. He was under the command of camp commandant Christian Wirth, and he also served as Wirth's liaison to Globocnik. For his work in the implementation of Operation Reinhard, Oberhauser was promoted from SS-Hauptscharführer to SS-Untersturmführer, effective 20 April 1943, reaching officer rank in the SS. Previously, the Reichsführer-SSHeinrich Himmler had made a personal visit to the Operation Reinhard camps, including Bełżec, on 12 February 1943, and had decided to promote Oberhauser. In the 21 January 1965 judgment of the Munich District Court I, his work at Belzec is described as follows :
Transfer to Italy
After the completion of Operation Reinhard, Oberhauser, along with many of his colleagues, was sent to northern Italy in the group :de:Sonderabteilung Einsatz R|Sonderabteilung Einsatz R to participate in anti-partisan warfare and the deportation and killing of Jews there. He was promoted to the rank of SS-Obersturmführer on 30 January 1945. Purportedly, Oberhauser was commandant of Risiera di San Sabba until its closure in late April 1945. He then went to Austria with his unit, and was arrested by the British authorities in May 1945 in Bad Gastein.
Arrest and trial
After his release, Oberhauser was employed as a sawmill worker in Bevensen. On 13 April 1948, he was arrested during a stay in the Soviet occupation zone. On 24 September 1948, he was convicted by the Soviet Military Administration in Germany of violating :de:Kontrollratsgesetz Nr. 10|"Control Council Law No. 10" of 20 December 1945, by his membership in a criminal organization and his killing of victims in Grafeneck, Brandenburg and Bernburg. Oberhauser was sentenced to 15 years in prison and 10 years deprivation of civil rights. He was granted an amnesty on 28 April 1956, and released after only 8 years. Following his release, Oberhauser served as a casual labourer, bartender and waiter in Munich. In 1963 the Bełżec trial began and Oberhauser was one of 8 defendants charged with war crimes committed at the extermination camp. On 30 January 1964, all of the defendants but Oberhauser were acquitted due to the collapse of the prosecution case but re-arrested shortly thereafter. Oberhauser appeared before the court again in January 1965. He was found guilty of a number of charges, namely:
Five other crimes of aiding and abetting collective murder in each of 150 cases.
Oberhauser was sentenced to 4 years and 6 months imprisonment. He was released after serving half of his sentence. Oberhauser was sentenced to life imprisonment in absentia for his crimes committed in Italy, but the Italian extradition request failed. Oberhauser died on 20 November 1979 in Munich. Oberhauser was unwillingly filmed for Claude Lanzmann's documentary Shoah, released in 1985.
