Into That Darkness, by Gitta SerenyRead about the other books on the list.
How is it possible that Franz Stangl, a kindly, unassuming, mild-mannered family man and policeman from the small Austrian city of Linz became the commandant of the Nazi death camp Treblinka, where he wore white riding breaches to oversee mass murders of Jews? Gitta Sereny conducts her months of interviews of him in prison — as well as interviews with his wife and acquaintances — with her customary decorum, intelligence, and respect. One of her many outstanding strengths as a journalist is that she is entirely committed to understanding her subjects rather than demonstrating that she and her readers are unassailably superior.
--Marshal Zeringue