I wanted to like this book more than I ultimately did. The central idea of the "lessons" was innovative and very scary. Black has a solid, competent writing style, even when he tends to go overboard on exposition and plot twists. For the most part, he does know how to pace events and create suspense to make a reader stay glued to the page, and how to create characters that, even when they're less than likable, are interesting to read about.
But I almost couldn't handle the level and graphic nature of the violence. Even as a confirmed thriller reader, I found Black's level of gory detail to be off-putting. It felt lingering and gratuitous, as though the author was trying for maximum shock value. Mission accomplished, as far as I'm concerned, although a better book would have resulted if he had instead concentrated on constructing a more plausible plot and refining his already well-written characters.
I'd try, cautiously, another book by Black, in the hope of finding toned down violence and a more tightly constructed story.
This book was SCARY! The Killing Lessons is a nail-biting thriller that is not for the faint of heart. Should appeal to fans of Karin Slaughter.