The attorney who helped push for a criminal prosecution in Trayvon Martin's shooting said Thursday that he's joining the fight to reopen an investigation into the death of a Georgia teenager whose body was found inside a rolled-up wrestling mat at school. ... Johnson's family asked the Justice Department to get involved, arguing that authorities failed to investigate Johnson's death thoroughly because he's black. But the Justice Department found insufficient evidence to support an investigation. U.S. Attorney Michael Moore in Macon has been monitoring the case...