Who is Johannes Paul Kremer from 'the Good Old Days': The Holocaust as Seen by Its Perpetrators and Bystanders and what is their importance?

Kremer received a PhD in 1914 and an MD in 1919. By 1929 he was a professor and university lecturer. From 1936 through 1945 he was a senior lecturer on heredity, radiology, and anatomy. He joined the Nazi party in 1932 and the SS in 1934. During university vacations he was appointed duties as an SS officer, once serving at Dachau. He served for two months at Auschwitz during which time he kept a diary, excerpts of which are presented in the book. After Auschwitz, he received a promotion and returned to his university work where he enjoyed more promotions within the SS. He was arrested in late 1945 and was deported to Poland in 1946; sentenced in 1947 to death, his sentence was later commuted to life in prison. He was released in early 1958 for good behavior. Later in 1958 he was arrested again and sentenced to ten years' imprisonment as an accessory to murder—however, his sentence was deemed already served. Kremer's diary excerpt is one of the most-chilling documents in the book.