Sarah Childress, for Frontline: “The Florida killing of Trayvon Martin, an unarmed black teen earlier this year, has brought national attention to the laws that allow people to use lethal force to defend themselves. At least 20 states have laws with provisions that don’t require civilians to flee from an intruder before fighting back, according to the National Conference of State Legislatures. Of those, eight states, all of them in the south, specifically use the phrasing, ‘Stand Your Ground.’ That includes Florida.”