Outrage over what? I believe that your suggestion that there is a double standard is misplaced. The Martin killing got attention because it appeared that the police were not concerned about the killing of a black kid. The case took on a life of its own after that, but the initial outrage was over the appearance of unequal justice. Since our criminal justice system has always been unquestionably skewed against black people, that concern was understandable in the Martin case.