Lorenz Hackenholt (26 June 1914 – missing 1945, declared legally dead as of 31 December 1945, but believed to have still been alive)[1] was a member of the Schutzstaffel (SS) with the rank of Hauptscharführer (First Sergeant).

According to Werner Karl Dubois, another camp guard transferred to special duty with Hackenholt: Photographs of extreme cases of mental illness were shown to us.

[4] 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.

Hackenholt returned to Poland and was sent to Bełżec, a remote labour camp near the rail station,[5] to conduct experiments to establish a method for the mass-murder of Jews by gassing.

[3] 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.

[4] In December 1943, Hackenholt and other personnel from Operation Reinhard were transferred to northern Italy (Trieste),[4] where they attempted to find and murder the few remaining Italian Jews.

Chris Webb, however, reports that Hackenholt avoided being shot and was released from custody by the decision of the commander of the Einsatz R, Dietrich Allers.

What is certain is that he disappeared[2] 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.

[9] In 1961, West German Police, interrogated Hackenholt's former colleague Hermann Erich Bauer, then serving a life sentence in Berlin.

Bauer stated that Hackenholt had definitely survived the war, because he had met him in 1946 near Ingolstadt, Bavaria,[4] where he allegedly worked as a driver or courier.

Bauer stated that Hackenholt had assumed the identity of a dead Wehrmacht soldier named Jansen, Jensen or Johannsen and lived with a woman he had met in Trieste.

Archives and records of offences were examined, as well as numerous inquiries to potential witnesses to determine whether a driver named Jansen or similar was working in the Ingolstadt area.

British researcher and historian Michael Tregenza spent many years exploring Hackenholt's postwar whereabouts and was repeatedly warned against looking for him.