Joseph Mengele was a German physician and a member of the Nazi Party during World War II. He is best known for his role at the Auschwitz concentration camp, where he conducted inhumane medical experiments on prisoners, particularly targeting twins and individuals with disabilities. His actions contributed to the suffering and deaths of many innocent people. After the war, Mengele evaded capture and fled to South America, living in countries like Argentina and Brazil. He remained a fugitive for decades, and despite efforts to locate him, he died in 1979 without facing justice for his crimes.