How does Stand Your Ground work and who helped put it all over the map? Read the inside story: How the NRA and Its Allies Helped Spread a Radical Gun Law Nationwide.

Update, 6/11/12: A new study from Texas A&M University shows that SYG laws result in no crime deterence—while adding 500 to 700 homicides per year nationally across the 25 states with the laws.

Map production: Tasneem Raja, Jaeah Lee and Ben Breedlove; Research: Hannah Levintova and Adam Weinstein