The Basic Self-Defense Rule

The Basic Self-Defense Rule

Every self-defense claim starts from one sentence in the Model Penal Code. Section 3.04(1) makes the use of force against another person justifiable when the actor believes that the force is immediately necessary to protect himself against the use of unlawful force by that person on the present occasion.¹ That sentence holds three working requirements. The first is a belief on the actor's part that force is needed. The second is that the need be immediate, which means it exists on the present occasion and not at some earlier or later moment. The third is that the force being resisted be unlawful. The subsection is made subject to the rest of Section 3.04, whose later limits cut the baseline back for deadly force, for the initial aggressor, and for defenders who can retreat safely,² so the three requirements here are the starting point and the later limits narrow them.

The three parts share one theme, which the D.C. Circuit stated in United States v. Peterson. The court began from the premise that "[t]he law of self-defense is a law of necessity."³ It explained that the right arises only when the necessity begins and ends when the necessity ends, and that the necessity must look real and leave no other alternative before a taking of life is justified.⁴ The defendant in Peterson had gone into his house for a pistol and threatened men who were removing parts from his wrecked car, then shot one of them as he advanced with a raised lug wrench. The court affirmed his manslaughter conviction, and the challenged instructions concerned the aggressor and retreat questions taken up later in this chapter.⁵ The necessity framework nonetheless governs every one of those later questions.

The rule is built on necessity because of what self-defense displaces. The law generally forbids private persons from settling potentially fatal conflicts by their own hands, and self-defense is a limited exception to that prohibition.⁶ Such an exception is tolerable only where the state's ordinary protections cannot work, and that happens only in the moment of attack, when no officer or court can step in. Each of the three parts ties the defender's force to that moment, and each does so for its own reason. The belief requirement ties the force to the defender's perception of danger, because the defender must act within seconds on incomplete information, and a rule demanding certainty would punish anyone who guessed wrong about a threat that looked real. The immediacy requirement confines the exception to the interval in which the state cannot help: a threat that is over, or one that is still to come, leaves time for police and courts, and force used then amounts to retaliation or a preemptive strike. The unlawfulness requirement reserves the exception for wrongful aggression, since force the law itself permits is not a wrong that needs answering, and a rule letting both sides of one struggle claim self-defense would license both to fight.

The MPC and the common law phrase the first part differently. The MPC asks what the actor believes. The common-law statement in Peterson adds that the defender's beliefs must be honestly held and also objectively reasonable in light of the surrounding circumstances, and that the threat must be unlawful and immediate.⁷ Because both versions turn on belief rather than on truth, the widely accepted view does not require that force be truly necessary, which is why a reasonable but mistaken defender was classed above as excused rather than justified.⁸ Summaries of the doctrine often list six elements: the defender was not the first aggressor, the force was proportional, the attack was unlawful, the attack was imminent or under way, and the defender honestly and reasonably believed force was needed.⁹ The last four are the subject of this part of the chapter, and the first two belong to the limits that follow it.

The two scenes differ in one fact, which is when the threatened harm is to occur. Trent's fear is the same in both and Vega is a wrongdoer in both, yet only the first shove answers a threat that exists now. Students lose this issue when a sincere fear or a wrongful adversary stands in for a present need for force. When all three parts are met, the defense is complete and the defender is acquitted.¹⁰ The next three subsections take the parts in order, beginning with the defender's belief in necessity.

Belief in Necessity

The first of the three working parts in Section 3.04(1) is the defender's belief, and the statute places the inquiry inside the defender's mind. Force is justifiable when "the actor believes" that it is immediately necessary to protect against unlawful force on the present occasion.¹² The question is what the defender believed when the force was used, and it does not ask whether a neutral observer looking back would find the force truly required. Subsection (2)(c) points the same way by letting a person who uses protective force estimate the necessity under the circumstances as he believes them to be when the force is used.¹³ That clause fixes the moment of measurement, which is the instant of force, and the vantage point, which is the situation as the defender perceived it. The latitude has edges, since it applies except where the paragraphs on arrests, property claims, deadly force, and retreat require otherwise, and later parts of this chapter take those limits in turn.¹⁴

Earlier in this chapter the belief requirement was explained as a response to the pressure of the moment, since a defender must act before certainty is possible. It also does a second job, which is to confine the justification to force used for protection. The statute speaks of force used "for the purpose of protecting himself," so the belief in necessity has to be the thing that moves the defender to act.¹⁵ A person who kills out of revenge or malice cannot invoke the defense even if some danger happened to exist, because the defender never used the force to protect anything. Without an actual belief in necessity, the law would be offering protection to the vengeful along with the frightened.

The common-law formulation adds a second check on the same belief. In Peterson, in the setting of deadly force, the court required that the defender believe he was in imminent peril and that his response was necessary, and that these beliefs be honestly entertained and also objectively reasonable in light of the surrounding circumstances.¹⁶ Summaries of the doctrine list the two qualities as separate elements: an honest (subjective) belief in the need for immediate self-defense and an objectively reasonable one.¹⁷ Each screens out a different claimant. Honesty filters the person who never feared anything, and reasonableness filters the person whose sincere fear no ordinary person in that position would share. Tort law uses the same structure for the privilege of self-defense, so an honest but unreasonable mistake about an impending attack is no defense, while an honest and reasonable one is.¹⁸ Reasonableness depends on the situation, which is why testimony about the effects of prior battering is offered to help the jury judge whether a defender's fear was reasonable, although such testimony is not itself a defense.¹⁹

Set side by side, the Model Penal Code text says the actor believes and the common law says the belief must be reasonable, which looks like a clean split. The split is less sharp than it appears, because the opening words of Section 3.04(1) make the whole rule subject to Section 3.09, and reasonableness returns to the analysis through the mistake rules.²⁰ Whether a belief that is honest but unreasonable can still support the defense is therefore a mistake question, and the section on mistake near the end of this chapter takes it up. For present purposes the working distinction is that the Code's basic rule asks about the actor's belief, while the common law asks about a belief that is both honest and reasonable.

The mugger who points a finger through a jacket shows the belief doing its work. The mugger demands money and points what appears to be a gun, and the defender reasonably believes a shot is coming, particularly because muggings in the neighborhood have ended in shootings even after the victim paid. The defender fires first, and later evidence shows the weapon was only a finger and that the mugger would never have harmed anyone. Because the defender's mistaken beliefs about the gun and about its use were reasonable, the defense survives the discovery that no gun existed.²¹ The defense asked about the defender's belief on the circumstances as they appeared, so the absence of a real gun did not matter.

The two scenes separate on the fact the rule cares about, which is whether the defender perceived a need for protective force. The mugger's victim was wrong about the facts and keeps the defense, while Hale was right about the facts, since Voss was harmless, and has no defense because she never held the belief at all. Students lose this issue when they treat the absence of a real threat as the end of the claim. A missing threat is where the inquiry into the defender's belief begins, and a belief with no reasonable basis is a separate problem reserved for the mistake rules.

Immediate Necessity

The second working part of Section 3.04(1) concerns timing. Force is justifiable only when the actor believes it is "immediately necessary" to protect against unlawful force "on the present occasion."²³ Two limits sit inside those words. The need must be immediate, so a harm that may arrive next week does not qualify, and the need must belong to the present occasion, so a threat that has already run its course does not qualify either. The Peterson court described the same window by saying that the right of self-defense arises only when the necessity begins and ends when the necessity ends.²⁴ Its conditions for the use of deadly force include that the threat be unlawful and immediate.²⁵

The two edges of that window exist for different reasons. At the front edge, a threat that is not yet immediate leaves the defender with other choices, such as leaving, calling the police, or waiting to see whether the threat is carried out. Force used while those choices remain open is not a last resort, and the defender who acts early is betting on a future that has not happened. At the back edge, once the attack has ended, force can no longer prevent any harm, because the harm has either been done or abandoned. What force can still accomplish at that point is punishment, and the law reserves punishment to the state. Together the two edges confine the right to the interval in which no one else can protect the defender and force still can.

The common law and the Code word this timing requirement differently. The common law required imminence, and the Code substitutes the phrase "immediately necessary on the present occasion," which turns attention from the timing of the possible attack to the necessity of using force.²⁶ In most cases the two phrasings give the same answer, because an attacker who is already swinging a weapon is both about to strike and a reason to act now. They come apart only when the defender can argue that waiting would forfeit the only effective chance of protection, even though the blow is not yet about to fall. That is the setting in which the Code's wording gives a defender room that the word imminent would withhold.

The two scenes differ in one fact, which is whether the threat exists when the force is used. D's fear and V's wrongfulness are the same in both, so neither can be what moves the answer. Students lose this issue when they treat a threat already made as an attack already under way. In the first scene force answers an attack that exists, and in the second it answers the memory of one.

The hardest application of the timing requirement arises when a person who has suffered long-term abuse kills the abuser at a moment of apparent calm. The cases fall into two groups. In confrontation cases, the abuser's overt conduct would not look to an outsider like the classic imminent attack, yet within the history of that relationship an attack may appear imminent or under way, and expert testimony on the effects of battering helps the jury see how the defendant perceived it.²⁷ Non-confrontation cases are harder, because the defendant kills while the abuser sleeps or is otherwise doing nothing that can be read as an attack, and courts are generally unsympathetic to self-defense there. In State v. Stewart the Kansas Supreme Court held that when a battered woman kills her sleeping spouse and no danger is imminent, the killing is not reasonably necessary and no self-defense instruction may be given, reasoning that a contrary holding would allow the execution of the abuser for past or future acts.²⁸ Other courts have refused the instruction on comparable facts: the West Virginia Supreme Court affirmed the refusal in State v. Smith, and the Pennsylvania court in Commonwealth v. Grove found no evidence that the defendant reasonably believed in imminent danger on the present occasion.²⁹

The Code's wording changes the argument without settling the result. Because the common law required imminence and the Code asks instead about necessity on the present occasion, the Code gives such a defendant a stronger argument, and the sleeping-husband cases such as State v. Norman show the difference most vividly.³⁰ The argument is still an argument. The defendant must have believed that force was immediately necessary, and at common law that belief must also be reasonable. A court that sees no present need at all will refuse the instruction, so the jury never decides the question. Where the claim does go forward, the jury decides whether, in light of the whole history, force was necessary on that occasion. The accurate description is a contested question that may reach the jury, with the Code's wording favoring the defendant more than the word imminent does.³¹ The last of the three working parts, the unlawfulness of the force being resisted, is taken up next.

Unlawful Force

The third working part of Section 3.04(1) sits in the phrase "unlawful force by such other person."³³ That word unlawful does the sorting. Self-defense answers a wrong, so the force the defender meets must be wrongful in the legal sense, and the usual shorthand is that the other party's conduct amounts to a crime or a tort.³⁴ A fuller definition describes unlawful force as force directed at a person without that person's consent that is a criminal offense or an actionable tort, and ties the definition to Section 3.11 of the Code.³⁵ The common-law checklist carries the same demand as its own element, that the threatened attack be unlawful.³⁶ A defender can therefore satisfy the belief and timing parts discussed above and still fail here, because those two parts describe the defender's state of mind and the clock, while this one describes the legal character of what the other party is doing.

The first consequence is that force the law permits is not unlawful force, even though it is force. A person holding a privilege, meaning a legal entitlement to do what would otherwise be a crime or a tort, commits no wrong while acting within it, and the clearest example here is a property owner's entitlement to use reasonable non-deadly force against attempted theft.³⁷ The reason follows from what self-defense is for. The justification lets a person resist wrongful aggression, so when the other party's force is lawful there is no wrong to resist. Letting the first actor fight back anyway would reward the original wrongdoer and strip the privilege of content, since the property owner could protect the property only by accepting a fight in which the thief could also claim self-defense. The law avoids that result by treating privileged force as outside the justification's reach.

The pickpocket illustration shows both sides of the line. D tries to pick V's pocket, and V, who is not a trained or dangerous fighter, hits D lightly with a fist. V is using reasonable non-deadly force to defend property, so V's force is not unlawful and D has no right to use any force in self-defense.³⁸ Now change one fact. V instead pulls out a gun, aims it at D, and starts to pull the trigger, although V realizes that D is unarmed and not dangerous. D may probably tackle V and knock the gun away, because V has gone beyond the scope of the privilege to use reasonable force to defend property.³⁹ D is attempting a theft in both versions and V is protecting the property in both, so neither of those facts moves the answer. What moves it is whether V's force stayed inside the privilege.

The second half of the rule follows from the first. A privilege has a scope set by what reasonable protection requires, and force beyond that scope has no legal approval behind it, so the excess is generally treated as unlawful.⁴⁰ The right to resist revives at that point because the only thing that had silenced it, the other party's lawful entitlement, no longer covers what the other party is doing. Reviving the right does not enlarge it. The defender's response still has to be no more than reasonably necessary to meet the threat.⁴¹ Whether a person who began the encounter by wrongdoing keeps the defense at all is a separate question that the initial-aggressor rules answer later in this chapter.

The last part of the rule concerns the defender's own error about whether the force is unlawful. A defender who reasonably misjudges the other party's force as unlawful is protected, because the defense is generally not voided by a reasonable mistake.⁴² In most states the protection ends when the mistaken belief that the force was unlawful was itself unreasonable.⁴³ The reasoning matches the reasoning behind the belief requirement: the defender must judge in an instant and from appearances, so the belief is measured against what a reasonable person would have concluded, even if the facts later turn out otherwise. The mistake rules near the end of this chapter develop how unreasonable beliefs are handled.

The two scenes differ only in whether appearances reasonably suggested unlawful force. The stranger is harmless in both, so the reasonableness of Wen's reading is what carries the result.

Students lose this issue when they treat force aimed at the defender as automatically unlawful. Being struck, shoved, or threatened does not by itself open the defense. The question is whether the other party was entitled to act, and a thief who meets lawful protective force has nothing to resist. The Code's basic rule is also expressly "[s]ubject to the provisions of this Section," which means the rest of Section 3.04 can withhold the justification.⁴⁴ The next part of this chapter takes up two provisions in Section 3.04(2)(a) that do so in settings where the force met may well be unlawful: resisting an arrest known to be made by a peace officer, and resisting a property possessor who acts under a claim of right.