I was curious to learn how a police unit could devolve into becoming mass murderers. the book provides a very thorough factual overview and theoretical framework to understand that process. It is a very good and subtle analysis.
The narration was very good while he was speaking English. While I can’t vouch for the the accuracy of his Polish pronunciation, his pronunciation of German words, phrases and names was positively distracting. As a speaker of German I could barely understand his pronunciations at times. It would have been time well spent to improve that before recording the book.