After joining the SS, he was stationed in Thuringia, and his first concentration camp service was in Buchenwald – he served as a cook and instructor there. When World War II broke out, he was assigned to staff of Operation T4, a secret program to exterminate the mentally ill and mentally disabled. He worked as a cook in several euthanasia centers throughout Germany. Like many involved in Operation T4, he was sent to occupied Poland to take part in Jewish extermination operations.

Kurt Franz’s first allocation was the Belzec extermination camp. In recognition of his merits in carrying out the “Reinhardt operation”, Christian Wirth – the chief inspector of all the extermination camps taking part in it – sent Franz to Treblinka, where he became deputy commandant.

At the camp, Kurt Franz was responsible for supervising Arbeitsjuden, or Jewish prisoners who were temporarily saved and did work in the camp. The prisoners gave him the nickname “Doll” because of the beauty and elegance he displayed. But above all, Franz was described as a sadist who often personally tortured and murdered prisoners. He took great pleasure in flogging naked prisoners or performing inspections where he decided whether a person was fit for work or not, and thus whether he would be sent to the gas chamber. Eyewitnesses who survived the Treblinka camp testified that Franz personally executed prisoners, arranging “shooting contests“. To abuse Jews, he trained his dog to attack prisoners on command. Interestingly, in their memoirs, the survivors claimed that the dog Barry was only aggressive in front of his owner, while without him the dog allowed him to be petted and even played with the prisoners.

During the prisoner revolt at Treblinka, Kurt Franz was not in the camp. His superior was transferred, while the camp was ordered to be liquidated. This task was given to Franz. Under his supervision, the prisoners dismantled the fence and buildings, backfilled the mass graves, and a farm was established on the camp grounds. Kurt Franz later took part in the execution of the last Treblinka prisoners.

In the final months of the war he was taken into American captivity, but was not recognized. Released, he returned to his native Düsseldorf, where he worked as a laborer and cook. He was arrested in 1959 while Germany was investigating the crimes committed at Treblinka. On the occasion of his capture, an album titled “Beautiful Times” was found in his home, which contained photographs he had taken at Treblinka.

At his trial in 1964-1965, he was found guilty of murdering at least 139 people and complicity in the Holocaust. He was sentenced to life imprisonment. Due to his health, however, he was released in 1993. He died in a retirement home in 1998.