Walter "J.J." Revear walked out of the Hillsborough County jail that day into hugs from relatives and questions from reporters. "Do you know what a break you got? Are you going to stay out of trouble now?" It was his 13th birthday, Oct. 20, 1995. And he was the chubby-cheeked face of a flawed juvenile justice system at a time judges wrestled over punishments for kids who committed grown-up crimes. The fifth-grader, who stood at 4-foot-6, had driven the getaway car in an armed robbery. The victim caught a glimpse of him, giggling. In court, he had to sit tall...