One of the big mysteries of this series is going to be is Micheal Garland guilty or not. It's going to get old after a while, especially since most readers have made up their minds one way or another during the first book. I still don't like Tony that much, not that I hate him but still.
The main mystery in this book is another serial killer case and this one hits a little close to home for Charlie. Who the killer is I won't say, but Charlie's friend Tam offers some hints that made it to clear who it was even before Charlie figured it out. Most of the action is very close to the end of the book, and it seemed a little rushed to me.