Eight years ago this November, 9-year-old Tyshawn Lee walked to his grandmother’s house wearing black jeans, an orange polo shirt and carrying a basketball. The boy, 83 pounds and 4-foot-8, was then lured into an alley by gang rivals of his father’s where he was shot in the head, police have said, revenge for an escalating gang feud that had resulted in at least two fatal shootings prior to ...