Given that this is a thriller set in Maine, it would be easy to describe it as a cut-price Stephen King clone, but I don't think that would be entirely fair. This is a decently written and plotted story. Some of the characters are a bit on the stereotypical side, but I've certainly seen worse. I worked out the main shape of it after reading the first chapter and wasn't substantially wrong in any of my predictions, but basically this is a reasonably well-written book which does pretty much what it says on the tin. And sometimes that what the reader wants.
I understand Gerritsen has written a series of detective novels, so I may well give those a try at some point