Trayvon Martin was killed for "walking while black"; The United States Justice Department must protect our citizens from reckless vigilantes like George Zimmerman, and from "Stand Your Ground" laws that allows anyone to manipulate circumstances, so she/he may kill someone with impunity.
As has been done MANY times before, when there has been a miscarriage of justice, the US DOJ MUST file charges against George Zimmerman for violating Trayvon Martin's civil rights.