This is the 7th in a series of books about a married pair of criminal profilers (Quincy and Rainie), but this is the only one I have read and I don't feel like I was missing anything at all. It can definitely stand alone.
Telly Ray and Sharlah Nash were born into a difficult home. Their parents were addicts, their father was abusive and their mother wasn't strong enough to stop him. Telly takes good care of Sharlah until the night he sees his father attack their mother with a knife. Then, Telly loses control and attacks his parents with a baseball bat, killing them both (this happens in the first chapter, it's not a spoiler!). Following this, the children are separated in foster care and each live very difficult lives trying to overcome the trauma of that night. Telly moves from home to home while Sharlah is in the process of being adopted by Quincy and Rainie, the criminal profilers.
Fast foward 9 years when a violent gunman is on the loose in their small Oregon town. Telly's current foster parents are dead, along with two victims in a nearby gas station. Telly is seen shooting out the camera of the gas station security cameras and is on the run. Quincy and Rainie have to begin searching for their daughter's long lost brother, while trying to keep her safe at the same time. But is the case as cut and dried as it seems?
What follows is an exciting mystery with lots of twists and turns. There are lots of great characters who work together to solve the mystery. Flashbacks are given to help tell the backstory and the past and present are really well woven together.
I've never read anything by this author before but I definitely would again. This would be a great summer read, take it along with you on your vacation!