In Florida, a grand jury will now look into the killing of an unarmed black teenager. And, after weeks of calls for more investigation of the case, the U.S. Justice Department is also involved. Trayvon Martin was shot to death by a neighborhood watch captain late last month. The shooter, who is Latino, says he acted in self defense. But an attorney for Martin's family provided a different account on Tuesday, saying the teenager thought he was being stalked.