Stark attended the Volksschule in Darmstadt from 1927 until 1931. He had a strict upbringing at the hands of his father, who as a police officer, gave his sons a "typically Prussian education". However, Stark failed to live up to his father's academic expectations, and thus it was decided that the young man needed firmer guidance. Stark left the Realgymnasium in 1937 in the seventh year to apply for Reichsarbeitsdienst or Wehrmacht, but both rejected him due to his age. Notwithstanding, Stark joined the 2nd SS Death's Head brigade 'Brandenburg' in December as its youngest recruit with the written permission of his father, as the SS accepted 16 year old applicants. At 16 and a half years old, Stark was sent to Oranienburg, where he was the youngest recruit of the unit. There, the SS gave him an intensive indoctrination in the Nazi ideology. In January 1938 he was assigned guard duties at a concentration camp, which most likely was Sachsenhausen. After six months of basic training, Stark was granted his first home visit. He was strictly forbidden from disclosing at home what was going on at the camp. His father noticed that he appeared depressed, and for that reason, tried to get him out of the SS. From June 1938 to September 1939, he received further training at Buchenwald and Dachau concentration camps.
Auschwitz
At the rank of SS-Unterscharführer, he was posted to Auschwitz at the end of 1940 and worked as a Blockführer. In 1941 he was brought into the Political Department and became head of the admissions detail. In his continued efforts to get his son out of the SS, Stark's father was informed that the only way of doing so was to have him apply to continue his education. From Christmas 1941 to March 1942, Stark returned to his home town and took his final exams as an external candidate at the Justus-Liebig-Gymnasium. Stark admitted to the shooting of prisoners at Auschwitz: Stark also participated in the gassing of prisoners, specifically, the first gassing of prisoners in the small crematorium at the main camp. In a similar manner to his participation in the shootings, Stark stated that he was ordered by Grabner to check the number of prisoners. Around 200-250 Jewish men, women and children were ordered to enter the gas chamber. As they did so, medical orderlies climbed up the earth banks by the crematorium in order to get onto the roof of the gas chamber, from where they could insert the Zyklon B gas via vents in the roof; something which Stark admitted doing: In September 1942, Stark was promoted to SS-Oberscharführer. At the end of the year, he took leave again, enrolling himself at Frankfurt University where he studied law for a semester. An elite training course at Dachau and deployment on the Eastern Front were also parts of his career in the SS. He attained his desired career as a commissioned officer when, after attending an SS-Junkerschule, he was promoted to SS-Untersturmführer in November 1944. He was part of the Auschwitz staff from 15 December 1940 to 2 April 1943.
Post-war
Following deployment to the capital in the Battle of Berlin, Stark was taken prisoner by the Soviets in early May 1945. However, he managed to escape within a few days, and subsequently did temporary work on farms in the Soviet-occupied area. In Autumn 1946, he took agricultural studies at the University of Giessen, but pending denazification proceedings meant he had to end his studies. He continued his studies with work experience and teaching practice with the Hessian Agricultural Ministry, and in 1953, the year of his marriage, he passed the exam to qualify as an assessor.
Trial
Until his arrest in April 1959, Stark taught at agricultural schools and gave business advice with the Frankfurt Chamber of Agriculture. He was remanded in custody from the end of October 1963 to mid-May 1964. One Frankfurt police interrogator stated that Stark was "very forthcoming", and "talked about some things that we did not know at the time." In August 1965, he was found guilty of at least 44 instances of joint-murder, and sentenced to ten years in prison: the maximum sentence that could be imposed on a minor. Stark's father committed suicide after the war. In Stark's conviction, the court noted that: In his closing speech, Stark stated: Expert witness Dr Helmut Lechler described Stark: He was released from prison in 1968, and died on 29 March 1991, aged 69, in his hometown of Darmstadt.
