Hackenholt's full name was Laurenzius Marie Hackenholt. He was born on 26 June 1914 in Gelsenkirchen/Ruhr. His father was Theodor Hackenholt and his mother was Elizabeth Wobriezek. He attended the local elementary school until he reached the age of 14. He then became an apprentice bricklayer. After he passed the trade examination he worked on various building sites.
Concentration camp guard
In 1933, Hackenholt volunteered for the SS. After joining the SS he was sent to a training school on 1 January 1934. After that he volunteered for service in the army, where he was assigned to the 12th Engineers' Battalion. After two years military service he was discharged, and then joined the SS Death's Head troops. He was a skilled driver and mechanic and, beginning in March 1938, served at Sachsenhausen concentration camp in the motor pool. He also worked as a guard at Sachsenhausen.
, the so-called "Euthanasia Program", lasted from early 1940 until the summer of 1941 when the gassings were stopped on Hitler's orders. In November 1939 Hackenholt was assigned to Action T4, when he was transferred to Berlin for 'special duty'. This special duty was under Viktor Brack. According to Werner Karl Dubois, another camp guard transferred to special duty with Hackenholt: There were six T4 killing facilities. Hackenholt served in all of them. He drove a bus with the SS staff from facility to facility. He also removed the bodies from the gas chambers and burned them. For a while Hackenholt was a driver for SS-Untersturmführer Dr. August Becker, the T4 chemist who was responsible for delivering bottled carbon monoxide gas from I.G. Farben manufacturing plants to the T4 gas chambers. Hackenholt worked primarily in Grafeneck and Sonnenstein.
Operation Reinhard and beyond
In the fall of 1941, some of the Action T4 personnel, including Hackenholt, were transferred to Lublin Reservation in occupied Poland where they came under the authority of SS-Brigadeführer Odilo Globocnik. On vacation leave, Hackenholt went to Berlin to marry Ilse Zillmer, who was then 29 years old. Hackenholt returned to Poland and was sent to Bełżec, a remote labour camp near the rail station, to conduct experiments to establish a method for the mass killing of Jews by gassing. Hackenholt set up three gas chambers in an insulated barracks. Using engine exhaust, piped into the chambers from a disassembled Soviet tank, Hackenholt killed over 50,000 Jews in one month. In August 1942, Hackenholt built and operated newer and larger gas chambers at Belzec. Once Belzec came into operation, a sign was placed over the gas chambers which said "Hackenholt Foundation"; with potted geraniums on either side of the entrance. Hackenholt also designed and operated gas chambers at the Treblinka and Sobibor extermination camps. Hackenholt, who was called "Hacko" by other guards, was a tough, large man who was willing and able to do any task at the extermination camps, although he reportedly balked at cleaning up seeping corruption from bodies rotting in mass graves. At Belzec, where all ages of people were killed, some Jews, because of infirmity or age, could not enter the gas chamber. These people were instead laid down in the mass graves, and, according to the testimony of other guards, shot by Hackenholt. In 1943, when Himmler ordered the mass graves at Belzec to be reopened and the bodies burned, Hackenholt was in charge of the operation. Himmler considered Hackenholt to be "one of the most deserving men of Operation Reinhard". In December 1943, Hackenholt and other personnel from Operation Reinhard were transferred to northern Italy, where they attempted to find and kill the few remaining Italian Jews. In 1944 Hackenholt was awarded the Iron Cross for his role in Operation Reinhard.
Post-war disappearance and investigation
Hackenholt disappeared after 1945, and based on an application by his wife was declared dead by a Berlin court on 1 April 1954, with an official date of death of 31 December 1945. Hackenholt was supposedly killed in Italy in 1945, possibly by execution for selling guns to the partisans. However this was never quite certain. The West German authorities began an investigation in 1959. They were able to locate Hackenholt's wife and mother. Both certified that Hackenholt had not been heard from since the war, and surveillance of the wife's residence showed there were no attempts by him to visit her there. In 1961, the West German police were able to find Hermann Erich Bauer, who had been in the SS with Hackenholt. Bauer claimed that Hackenholt had definitely survived the war, because he had met him in 1946 near Ingolstadt, Bavaria. Hackenholt was going under a false name that he had acquired from a dead soldier. Bauer's statement was corroborated by a former Sobibor guard, who likewise said he had met Hackenholt after the war. The West German police conducted an investigation but were not able to locate Hackenholt, or to determine whether he might still be alive.
