One sunny afternoon in 1982, a young businessman experienced a terrifying mugging in New York City that shook him to his core. Tortured by nightmares about the teens who roughed him up, Steve Mariotti sought counseling. When his therapist suggested that he face his fears, Mariotti closed his small import-export business and became a teacher at the city's most notorious public school--Boys and Girls High in Bed-Stuy. Although...