As three Chicago police officers face charges for covering up the police shooting of 17-year-old Laquan McDonald, we will look at the cases of Philando Castile, Sam DuBose and Sylville Smith—three black men killed by police officers. In recent weeks, two of the officers were acquitted; one had a mistrial. Our first guest writes, "[I]t is not just police officers who are on trial. America is on trial. Either these deaths are justified, and therefore America is just, or these deaths are unjustified, and America is unjust."