I thought this book could be fascinating - I have 3 children of my own, and in the wake of some of the horrendous shooting in the last few years, I've often thought about the families of the shooters and how a parent would cope with knowing that her child had done something like this. Unfortunately, this book is not particularly illuminating or thought-provoking. The author has everyone express the responses that one would expect, but it felt as if everyone was just going through the motions.
I didn't feel any emotional connection to anyone in this book - all stereotyped characters, all mouthing the words that you would expect from them, but none of them with any depth. I got very tired of the narrator/father's whining about how he was getting older - well, yeah, that's gonna happen whether your kid does something awful or not.
I also got tired of the long discussions of other assassins/mass killers throughout history. It seemed as if the author couldn't decide whether he wanted to write this book, or a treatise on notorious killers. Since the book stated about a million times that the father, a doctor, had to treat this like a diagnosis, I assume that the point was that he had to examine all this stuff to try to understand, but it felt a lot more as if the author had done this research and he didn't want to waste it by not cramming it all in.
And I also wish the author had done a little more research on other details. For instance, the parents keep talking about how they might file an appeal of the conviction if he won't, but they don't because he is so opposed to it. They can't do this! He was 20, he was convicted as an adult and found legally competent, and his parents can't file an appeal of his conviction. Similarly with FOIA requests - they try to FOIA someone's military service records and the request gets denied on some sort of "security" reasons - well, there's a privacy exception to FOIA requests as well.
Overall, I thought the book relied on stereotypes and pat answers.