I read this book for a book club and so I didn't DNF it. This book was a waste of time for me since I do not understand the point of this book - there was no thriller aspect, there wasn't much legal drama, and the "twist" was just stupid and felt like it was just put there. 
This book was also just poorly written because:
1. It was structured in a way that made me drag through the story, especially during Part 2. Honestly this book turned into a historical fiction novel during Part 2, except a badly written one since I was left desensitized after all the info/trauma dumping.  It felt like Grisham was like "No one talks about this part of WWII so I WILL"
2. He used passive voice the entire time and so you couldn't really care or understand the characters. It felt like you were being told step by step events and you weren't able to immersive yourself in the story at all.
This book should've been way shorter, by about 100 or so pages, since most of it was unnecessary.

Basically I have ultimately decided that John Grisham books and I are not meant to be friends. This is my 3rd book by him and hopefully it will be my last.