What do "stand your ground" laws allow for — and which states have them?

A White man claiming self-defense after he shot a Black teenager this week when he rang the doorbell of his Kansas City home has reignited the debate over "stand your ground" laws. 

Andrew D. Lester, who has been charged with two felonies, has not defended himself against the charges, and it's still unclear whether he would use Missouri's "stand your ground" laws in his defense.

Lester, 84, told police he shot 16-year-old Ralph Yarl because he was "scared to death," when the doorbell rang just after he went to bed. The teenager was picking up his younger brothers from a sleepover, but rang the wrong doorbell when he was shot and seriously wounded.