This book is a 101 course in "how not to write a thriller". The characters lack any sympathetic response from the reader. They are cardboard cutouts. Flat. Every chapter is formulaic: intro sentence, brief paragraph description of situation, and then plot. Crosses detective work is almost lacking. He spends most of his time running from one murder scene to another.
Patterson's attempt to hold reader interest is to have another murder victim every 3rd chapter. Only Titus Andronicus has more rapes and murders.
Cross never discovers the "bug" that Guidice put in his house.
Patterson's handling of the foster child Ava is boring. There is lots of words, but no real emotional content. Reader does not even like Ava the way Patterson has described her.
Patterson breaks an important writer's rule: Show, don't tell. Patterson spends most of the book telling.
The language level is about at the fourth grade.