The Frailty of Flesh — Sandra Ruttan

The police got the call: A four-year-old boy had been found beaten to death in the park. But almost as soon as Hart and Tain arrived at the scene, the case took a strange turn. They found the victim's brother hiding in the woods nearby. He said he saw the whole thing and claims his older sister is the killer. And she's missing.... When the boy's father is notified that his son is dead, his first response is to hire a high-powered attorney, who seems determined to create every legal roadblock he can for Hart and Tain. So now the search is on for the missing girl. But the clock is ticking, and the case is about to get even stranger.