The ‘Disappearance’ of
A Report on the 1959-63 West German Police Search for
the Gas Chamber Expert of the Aktion
Reinhard Extermination Camps ©
stationed with an SS-unit in northern Italy. A copy of Hackenholt's SS file was obtained from the Berlin Document Center, the main repository for the personal files of all former members of the SS and Nazi Party, administered at that time by the US military authorities in West Berlin.  The file, which also contained his hand-written curriculum vitae dating from 1941, showed that Laurenzius (Lorenz) Marie Hackenholt was born on 25 June 1914 in Gelsenkirchen/Ruhr, the son of Theodor and Elizabeth Hackenholt, nee Wobriezek. After attending the local elementary school until the age of 14 he became an apprentice bricklayer and on passing the trade examination was employed on various building sites until 1933 when at the age of 19 he volunteered for the SS. Hackenholt's c.v. continues:
After joining the SS I was commandeered on 1 January 1934 to the Führerschule of SS- Abschnitt XVII and remained there until my discharge at the disbandment of the school. At that time I reported to the army as a volunteer and was called up to 12 Engineers' Battalion. After two years military service I was discharged. I then reported to 2. SS-Totenkopf Standarte (Death's Head Regiment). In November 1939 I was then commandeered to Berlin for 'special duty'. 
Certain important details omitted by Hackenholt from his c.v. were provided by one of his former SS-comrades, Werner Dubois, questioned in Schwelm by officers of Department 15 of the Northrhine-Westphalian Kriminalpolizei. Dubois had served before the war in the same SS-unit as Hackenholt. According to this witness, they both belonged to the 2. Totenkopf Brandenburg Division stationed at Oranienburg, north of Berlin, and when in March 1938 an SS vehicle depot was established at the nearby Sachsenhausen concentration camp, Dubois and Hackenholt were transferred to the camp staff as both SS-men were skilled motor mechanics and drivers with Class I-III driving licenses. At Sachsenhausen they also performed the more onerous task of concentration camp guards as well as serving as SS-drivers for the camp command and staff.
It was from the Sachsenhausen Kommandantur that the summons to 'special duty' had come in November 1939 when, together with two other members of the camp staff, Josef Oberhauser and Siegfried Graetschus (also employed in the vehicle depot) Hackenholt and Dubois were ordered to report to the Führer's private Chancellery at Voss Strasse 4 in Berlin. There, the four SS-NCOs from Sachsenhausen met six other SS-NCO who had also been commandeered from the concentration camp service. 
At Voss Strasse the 10 men were interviewed by SS-Standartenführer Viktor Brack, the head of Hauptamt II (Main Office II) of the Führer's Chancellery — an office which
 Since 1994, the US authorities handed over the Berlin Document Center files to the Federal German authorities. The archives are now administered as a branch of the Bundesarchiv in Koblenz (Aussenstelle Berlin-Zehlendorf).
 Bundesarchiv Koblenz, Aussenstelle Berlin-Zehlendorf (BKBZ), personal file Lorenz Hackenholt.
The other six SS-NCOs were: Kurt Franz, Fritz Irrmann and Herbert Floss from Buchenwald, and Johann Niemannn and Gottfried Schwarz from Dachau.