In a nutshell, this article in today's New Hampshire Union Leader (New Hampshire's largest daily paper) contains a good summary of the general rule for justifiable application of deadly force. It also shows that some states use good sense when both writing and enforcing their laws:
Sep 23, 6:37 PM EDT
Rochester man who shot home intruder won't face charges
CONCORD, N.H. (AP) -- A Rochester man who fatally shot a home intruder was justified in using deadly force and won't face criminal charges, the attorney general's office said on Friday.
Geoffrey Hamann, 28, killed Bryan Gaedtke, 21, with a single shot to the chest early on the morning of Sept. 15. Gaedtke - naked, climbing the roof of the Hamann house and holding a tube of lubricant - had tried to break into other houses and ignored repeated warnings from Hamann to leave when the shooting happened, authorities said.
Police believe Gaedtke had been drinking and may have used drugs that night.
Hamann first spotted a man on his property around 1:45 a.m. and shouted at him to leave. When he was ignored, Hamann flashed an unloaded gun. But the intruder kept climbing, shouting, "I'm coming in to get you," according to the attorney general.
Hamann then loaded his gun and went downstairs to check on his five-year-old child. His wife, Jocelynn, had already gone to be with their 1-year-old.
When Hamann came back upstairs, he found Gaedtke in the hallway, headed toward the 1-year-old's bedroom.
"Mr. Hamann could see that his wife and child were still in the bedroom and so he was scared for his family," according the attorney general. Hamann then fired his gun once, killing Gaedtke.
Authorities concluded from their investigation that Hamann reasonably feared the intruder would harm him and his family. The two did not know each other, police said.
Gaedtke had had brushes with the law, including charges in Durham District Court for simple assault, criminal trespassing, criminal mischief and operating after suspension. He had his license revoked in 2003 for driving while intoxicated.
According to state law, a person can use deadly force when he reasonably believes another person is about to use deadly force against him. The law says a person must retreat from an encounter involving deadly force unless he is confronted within his own home or property.