Holding two doctoral degrees, in anthropology and genetic medicine, Josef Mengele worked in 1941 with the Genealogical Section of the SS Race and Resettlement Office in Posen, screening persons for hereditary and racial fitness. In 1942 he joined the Waffen SS and was wounded in combat. Posted to Auschwitz in 1943, Mengele took rotations with other SS doctors at the unloading ramps, dispatching Jews to the gas chambers. Mengele also conducted experiments using Jewish and Roma (Gypsy) twin subjects. He either killed or ordered killed some of his subjects so that organs could be harvested for study.

Mengele was released from a U.S. detention center at the end of the war, and fled abroad. The anthropologist and geneticist who conducted research on twins and other captive subjects at Auschwitz remained in hiding in Argentina and Brazil until his death in 1979.