Raw Trayvon Martin 911 Tapes

Last month, 17-year-old African American student Trayvon Martin was shot and killed after purchasing candy on a street in Sanford, Florida, just a bit past 7 p.m. Who was his killer and why? The answers are not clearly known. But Melissa Harris-Perry walks through what is known about the sequence of events that night, with a set of facts that cause many suspicions.