Into that darkness (1974)

Gitta Sereny spent 70 hours interviewing Franz Stangl, commandant of the Treblinka and Sobibor extermination camps, in prison, and he died of a heart attack nineteen hours after she finished. The book is as close as a reader can come to the mind of a man who ran a death camp, and her questioning keeps circling one thing: how far he would admit his own guilt. There is no sensationalism here, only patience, which is what makes it so hard to forget. Demanding and disturbing, it belongs after the general histories, for readers ready to look at a perpetrator at close range.