Maybe I have just read too many books similar to this one, but I find Gregg Olsen's writing to be really predictable and just not that well written.
I have read three of his now, and I have been able to determine the outcomes of all three. I could even forgive that if the characters were more compelling or even likeable, but even the heroine is not, she's as flawed as the bad guys.
I should also mention implausible. At the end of the last book, for example, Foster notifies the cops who killed a child,but there is no further mention of that. Too much angst and too many flaws for me.