"Castle doctrine clears two arrested in St. Louis fatal shooting"

If someone breaks into your home and attacks you, how far should you have to retreat before you can fire your gun in self-defense?

Prosecutors have declined charges against two arrested in the shooting death of an intruder in April because they said the killing was justified under Missouri's "castle doctrine" law.
Police arrested a woman, 29, and a man, 37, after the April 6 shooting death of Emmett Terry. Police said Terry broke into his ex-girlfriend's home in the 4600 block of Oregon Avenue and tried to attack her.
Police have said the woman had had a restraining order against Terry.
Authorities say the woman shot and killed Terry, of the 1900 block of Semple Avenue. He died at the scene. . . .