Chillwater Cove by Thomas Lakeman

Peggy Weaver was ten years old when her best friend Samantha was kidnapped while they were playing together. Although Samantha was returned, there are parts of the ordeal that she could never speak about. Now Peggy is an adult and an FBI agent. When she receives some graphic photos of Samantha related to the crime, she is thrown back into that traumatic childhood event. Peggy has always felt that she didn't do enough for Samantha, since the only thing she could remember was the model of the car. Samantha also gets the photographs, so Peggy travels home to Tennessee to try and figure out what's going on. Soon after she arrives, Samantha disappears. Along with her father, who's the chief of police, Peggy uses all of her efforts to bring Samantha home safely. Unfortunately, a lot of obstacles stand in her way--Samantha's husband and father-in-law, a belief by some that she's too close to the case to be a good investigator, and her own father, whom Peggy starts to believe may be doing something illegal. Chillwater Cove is a thriller with a sense of place of a small Tennessee town. It also features a tenacious female main character who's trying to put the ghosts of the past to rest. The main character in Lakeman's first novel The Shadow Catchers, Mike Yeager, is Peggy's partner and puts in a small appearance in the book.