The Rag and Bone Shop by Robert Cormier
A seven-year-old girl is brutally murdered and a twelve-year-old boy named Jason was the last person to see her alive - except of course, for the killer. Unless Jason is the killer. A high-profile case follows, and everyone wants answers, including a powerful senator. The police call in an expert interrogator, a man named Trent, a man who always gets a confession. When Jason and Trent come face to face the battle for the truth commences.