A judge (county court level) was awakened in the dead of night (or before dawn, anyway) by noises in his front yard. The "perp" he shot happened to be the paper boy. (the more I think about it, the more it sounds like an urban legend). This was one of those stories you hear from your classmates in High School. Anyway, the judge was acquitted of all charges. (the time frame for this occurance was the early 1970's or late 1960's)

I've also heard of people being able to shoot "uninvited guests" who are in their homes and get away with it.