Self-Defense

Self-defense is a justification defense that permits a person to use force to defend themselves against an imminent unlawful attack. The defense, if successful, results in complete acquittal because the defendant's conduct is deemed legally justified rather than merely excused. The requirements vary between jurisdictions and between the common law and the Model Penal Code, but the core elements are consistent.

The defendant must have a reasonable belief that force is necessary to defend against an imminent threat. Imminence requires that the threat is immediate and present — not a past harm or a future possibility. Reasonableness is typically judged from the perspective of a reasonable person in the defendant's situation, though jurisdictions differ on how much of the defendant's subjective characteristics (size, prior experiences, knowledge of the attacker) are incorporated into the reasonable person standard. People v. Goetz explored this question in the context of a subway shooting, examining how the defendant's prior experiences with crime influenced the reasonableness assessment.

The force used in self-defense must be proportional to the threat. Non-deadly force may be used to repel a non-deadly attack. Deadly force — force intended or likely to cause death or serious bodily harm — is justified only when the defender reasonably believes they face an imminent threat of death, serious bodily injury, kidnapping, or (in some jurisdictions) sexual assault. Using deadly force against a non-deadly threat is excessive and defeats the defense.

The initial aggressor generally cannot claim self-defense unless they withdraw from the encounter and communicate that withdrawal to the other party. The duty to retreat, where it exists, requires the defender to retreat if they can do so in complete safety before resorting to deadly force. The castle doctrine and stand your ground laws modify or eliminate this retreat requirement. Battered spouse cases, such as State v. Norman, raise difficult questions about imminence when the defendant kills a sleeping abuser after years of sustained domestic violence.