Still no arrests in Trayvon Martin case after 27 days

It has been 27 days since 17-year-old African-American student Trayvon Martin was shot and killed within a gated community in Florida, and meanwhile his shooter, George Zimmerman, has walked free. MSNBC host Melissa Harris-Perry and Florida State Sen. Oscar Braynon join Politics Nation to discuss the standards of the “Stand Your Ground” law Zimmerman used to claim self-defense.March 24, 2012