§ 156. Prevention of offenses
A homicide is justifiable when committed by necessity and in good faith to prevent the commission of a felony attempted by force or surprise, but not when it is committed to prevent a mere misdemeanor.
According to the common law, it is the duty of every one, seeing any felony attempted, to prevent it by force, and if need be, by the extinguishment of the felon's existence. A person is justified in using deadly force in self-defense to prevent the commission of a forcible felony. According to some authorities the rule is not confined to felonies against the person, but may be applicable to felonies against property, although, according to other authorities, it is illegal for one to use deadly force to prevent the commission of a felony involving only property, unless an offense against a person involves great bodily harm or death or is used to prevent the commission of a felony in one's home.
To justify the killing, it must be done in good faith and under an honest and reasonable belief that a felony is about to be committed and that the killing is necessary in order to prevent its accomplishment. Accordingly, deadly force may be used if an unlawful intruder threatens the commission of a felony and the occupant reasonably believes deadly force is necessary. There need not be an actual necessity for the taking of life to prevent the felony, provided the circumstances are such as to impress the mind of the slayer with a reasonable belief in such necessity.
To be justifiable, the killing must be done while the person killed is in the act of committing the offense, or after some act done by him or her showing an evident intent to commit such offense. It generally must be done for the prevention of a felony and not as a punishment for a felony already committed, although, under some statutes, the killing is justified, in case of robbery, if it is done while the robber is in the presence of the victim or fleeing with the property taken. A defendant is entitled to use deadly force at the moment he or she is being robbed, but once the imminent threat of death or serious bodily harm dissipates, a lethal response is no longer warranted.
A statute providing that a person is justified in using deadly force if necessary to prevent another from committing certain enumerated crimes has been held to apply when one resident of a household uses force against resident of the same household.
Source: Westlaw
