There is an old 17th Century English saying: a man's home is his castle. Those words rang loud and clear in a recent case in Kalispell, Montana where an unarmed man was shot dead when he entered his neighbor's garage to confront the neighbor about an affair he was having with the man's wife. Because of the self-defense laws in Montana (similar to the ones in at least 20 other states), or in other words, the “castle doctrine,” a person can brandish a gun to ward off a threat. In addition, an individual does not have to flee or call the police before engaging in self-defense.
And what is that “threat?” At least when the event arises in one's home, the threat may be nothing more than one's belief that they are about to be assaulted. The County Attorney in Kalispell has made it clear that “You don't have to claim that you were afraid for your life” “You just have to claim that he was in the house illegally. If you think someone's going to punch you in the nose or engage you in a fistfight, that's sufficient grounds to engage in lethal force.”
In New York criminal law, the law surrounding self-defense is markedly different from Montana, as well as over 20 other states. Here, in New York, outside the home, if one reasonably believes that he or someone else is in imminent danger of deadly harm, one is justified in using deadly force as protection. As you can see, there must exist more than just a fear of assault of physical injury before using deadly force. In addition, the individual in fear of harm also has a duty to retreat, if they can do so safely, before using deadly force. With respect to homes, New York has a self-defense law based on the “castle doctrine,” but it is considered weaker than castle doctrine laws in other states. Within the home, the statute authorizes deadly force as long as the resident is not the initial aggressor. In addition, a person in possession of a home, must first reasonably believe that another person is committing or attempting to commit a burglary of the home before using deadly physical force that he or she believes necessary to prevent or terminate the burglary.