In May 1960, Isser Harel, director of Mossad (the Israeli intelligence agency), personally led the successful effort to capture Adolf Eichmann in Buenos Aires. He was also hoping to track down Mengele, so that he too could be brought to trial in Israel. Under interrogation, Eichmann provided the address of a boarding house that had been used as a safe house for Nazi fugitives. Surveillance of the house did not reveal Mengele or any members of his family, and the neighborhood postman claimed that although Mengele had recently been receiving letters there under his real name, he had since relocated without leaving a forwarding address. Harel's inquiries at a machine shop where Mengele had been part owner also failed to generate any leads, so he was forced to abandon the search.
Mengele's research subjects were better fed and housed than the other prisoners, and temporarily spared from execution in the gas chambers. He established a kindergarten for children who were the subjects of his experiments, as well as the preschool children from the Romani camp. The facility provided better food and living conditions than other areas of the camp, and included a children's playground. When visiting his young subjects, he introduced himself as "Uncle Mengele" and offered them sweets, while at the same time being personally responsible for the deaths of an unknown number of victims whom he killed via lethal injection, shootings, beatings, and his deadly experiments. In his 1986 book, Lifton describes Mengele as sadistic, lacking empathy, and extremely antisemitic, believing the Jews should be eliminated entirely as an inferior and dangerous race. Rolf Mengele later claimed that his father had shown no remorse for his wartime activities.