Field of Bones by J A Jance

Joanna is out on maternity leave when an important case comes to light.  A teenager brought home a human skull from his hunting trip and his mother made him turn it into the cops.  They go out to where he found it and find more bodies...

William Morrow and Edelweiss let me read this book for review (thank you).  It will be published September 4th.

They have one body that is fresh enough to autopsy.  Her dental work enables them to identify her.  They still have no idea why she was chosen or killed.

There's a sick serial killer out there that kidnaps pretty girls and rapes them when he feels like it.  He keeps them chained in the basement.  They get kibble dog food to eat.  If they get pregnant, he kills them.  He's also killed his brother so he can use his money.  But how are they going to find him? He's holding them in a ghost town his brother owned.  And he's operating under radar.

Joanna tries to stay home on maternity leave, but it just doesn't work.  One officer gets shot, one has a heart attack.  She takes the baby to work with her.

When one of the girls escapes, they finally narrow in on him.  But he's on the run.  Can they find him?