---
title: "Self-Defense"
type: Legal Rule
source: https://casebriefly.com/legal-rules/self-defense
---

# Self-Defense

Self-defense justifies the use of force when a person reasonably believes it is necessary to protect themselves from an imminent unlawful attack. Deadly force is permitted only when the person faces a threat of death or serious bodily harm.

## Definition

Self-defense is a justification defense that permits an individual to use reasonable force to protect themselves against an imminent threat of unlawful physical harm. When successfully raised, self-defense renders the defendant's use of force lawful, resulting in a complete acquittal. The defense reflects the principle that the law does not require a person to submit passively to unlawful violence.

The defendant must have an honest and reasonable belief that force is necessary to defend against an imminent threat. The belief must be objectively reasonable, judged from the perspective of a reasonable person in the defendant's circumstances. Some jurisdictions allow an imperfect self-defense claim where the defendant honestly but unreasonably believed in the necessity of force, reducing murder to voluntary manslaughter. The force used must be proportional to the threat: non-deadly force may be used against a threat of non-deadly harm, while deadly force is justified only against a threat of death or serious bodily injury.

Important limitations apply. The defendant generally cannot be the initial aggressor, though an initial aggressor can regain the right to self-defense by withdrawing from the encounter and communicating that withdrawal. At common law and in many jurisdictions, the defendant had a duty to retreat before using deadly force if retreat could be accomplished in complete safety, with the notable exception of the home under the castle doctrine. The MPC does not require retreat before using non-deadly force but does require retreat before using deadly force when it can be done safely, except in one's dwelling. Stand your ground laws in many states have eliminated the duty to retreat entirely.

## Elements

- Honest and reasonable belief in the necessity of using force
- The threat must be imminent (not past or speculative future harm)
- The threat must be unlawful
- The force used must be proportional to the threat faced
- The defendant must not be the initial aggressor (with exceptions for withdrawal)
- Deadly force is justified only against a threat of death or serious bodily harm

## Key Case

People v. Goetz, 68 N.Y.2d 96 (1986)

## Landmark Cases

| Name | Citation | Significance |
| --- | --- | --- |
| People v. Goetz | 68 N.Y.2d 96 (1986) | Established that self-defense requires an objectively reasonable belief in the necessity of force, not merely a subjective belief |
| State v. Norman | 324 N.C. 253 (1989) | Addressed the battered spouse context and held that imminence is strictly required, rejecting self-defense for a preemptive killing |
| People v. La Voie | 155 Colo. 551 (1964) | Affirmed that a person who is not the aggressor has no duty to retreat before using deadly force in Colorado |
| State v. Leidholm | 334 N.W.2d 811 (N.D. 1983) | Applied a subjective standard for self-defense, considering the defendant's personal experiences and perceptions |

## Exam Tips

- Always analyze imminence carefully; threats of future harm or retaliation for past harm do not satisfy the imminence requirement
- Check whether the defendant was the initial aggressor and whether they effectively withdrew before using force
- Distinguish between deadly and non-deadly force and match the proportionality requirement
- Look for imperfect self-defense as a fallback argument that can reduce murder to voluntary manslaughter

## Common Mistakes

- Confusing imminent with immediate; imminent means the threat is about to occur, but some jurisdictions interpret this more broadly in domestic violence contexts
- Forgetting the proportionality requirement; using deadly force against a non-deadly threat is not justified self-defense
- Assuming self-defense always requires actual danger; the standard is a reasonable belief of danger, not actual danger

## Mnemonic Or Memory Aid

"I-R-P-N" -- Imminence, Reasonableness, Proportionality, Not the aggressor: the four pillars of self-defense

## Related Rules

- defense-of-others
- castle-doctrine
- stand-your-ground
- voluntary-manslaughter-heat-of-passion

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Source: [Self-Defense — CaseBriefly](https://casebriefly.com/legal-rules/self-defense)