I'm not sure about officers, but I recommend They Thought They Were Free by Milton Mayer....it was a fascinating look into the mindset of the Nazis

I highly recommend this book.Not specifically holocaust, but it does go into it.

Soldaten: On Fighting, Killing and Dying Paperback


Basically, the British bugged some German POW quarters and made thousands of hours of transcripts. They sat around unused for decades since they had not been translated until the early 2000s when two German historians found them. The key thing is that these recordings were done surreptuously, so the Germans thought they were "unter vier Augen" (among 4 eyes), meaning confidential.

Really interesting stuff. Shows that while deep knowledge of the holocaust may not have penetrated (bear in mind, these are folks captured on the Western front) to everyone, everyone knew something. And beyond the holocaust, there were lots of atrocities that some Germans did that they were very cavalier about. I remember one case in which a German air crewman talked about machine gunning a wedding party they flew over, and then mentioned dropping anti-ship mines on towns.

Now, there are caveats. There were some Germans who said they saw bad stuff and knew it was wrong. Also, some people might have been claiming to have killed civilians to be "tough" in front of their fellow soldiers. But even with those caveats, it's generally chilling. I've spent a lot of time in Germany and I even spent a few days staying with a distant relative who was a German soldier on the East Front. I generally want to think well of them and chalk it down to a few extremists, but the book makes it clear that the guys doing the right thing were more atypical. Most tolerated or said nothing, a few were evil, and a very small number positively rejected the horrible acts their country did.