Concept
Limits on Deadly Force
Self-defense and justifiable homicide
Limits on Deadly Force
Section 3.04(1) asks whether the actor believes force is immediately necessary to meet unlawful force, and that inquiry governs every defensive act. Subsection (2)(b) adds a further screen for the most dangerous response. Under it, deadly force is not justifiable unless the actor believes it necessary to protect himself against death, serious bodily harm, kidnapping, or sexual intercourse compelled by force or threat.1 The same subsection goes on to impose two more limits on deadly force, one aimed at the person who provoked the encounter and one aimed at the person who could have escaped it safely. The next two parts of this chapter take those up as separate rules, so this part is confined to the threshold that every deadly response must clear first.
The threshold expresses proportionality. Self-defense is justified by necessity, and force beyond what the threat requires protects the defender from nothing further while it injures the other person. Deadly force sharpens the point because it risks the one harm that cannot be repaired. If the law allowed a defender to put a life at risk to stop a lesser harm, a defense meant to preserve safety would become a way of imposing a penalty far out of scale with the wrong, so the gravest response is tied to the gravest threats. The two sub-rules follow in order: first the line between deadly and non-deadly force, then the list of threats that open the deadly side of that line.
Deadly Versus Nondeadly Force
Subsection (2)(b) speaks only of deadly force, and that wording divides defensive conduct into two tiers.2 In general terms, deadly force is force meant to kill or seriously injure, or force the actor knows carries a substantial risk of doing so. Anything below that level, such as a shove, a slap, or a blow not expected to cause grave injury, stays under the general inquiry of Section 3.04(1), where the actor needs the ordinary belief in necessity, an immediate threat, and unlawful force to answer. The listed-harm screen has no application to that lower tier. Even there, necessity sets the ceiling: the force must stay within what the threat reasonably calls for, and it must stop when the threat stops.
The law keeps two tiers because the cost of a mistake differs between them. A defender who uses non-deadly force and turns out to have been wrong has inflicted harm that ordinarily heals. A defender who uses deadly force and turns out to have been wrong may have taken a life. So the law lets a defender act on a modest showing when the response is mild and demands a grave threat when the response is grave. Without that gradation, any unlawful touching could be answered with a gun, and a person who slaps another in a quarrel would risk death for it.
The two scenes differ only in the clerk's response, so the response is what moved the answer. The slap was equally unlawful in both, which shows that an unlawful attack alone opens the door to a non-deadly reply and leaves deadly force closed. The analysis shifts with the facts, however. If the customer had followed the slap by drawing a knife, the clerk would then face a threat of the kind the subsection lists, and deadly force could become available, subject to the remaining limits in the section.3 Students lose this issue when they stop at the attacker's unlawfulness, because deadly force requires a belief in one of the four listed harms.
Qualifying Threats
The list in subsection (2)(b) works as two requirements. The first concerns the harm: the actor must believe deadly force necessary to protect himself against death, serious bodily harm, kidnapping, or sexual intercourse compelled by force or threat.5 The second concerns the response: the belief must be that deadly force itself is necessary against that harm, so an actor who believes a warning or lesser force would suffice has not met the standard even when the threat is grave. Under the Model Penal Code, both beliefs are measured by what the actor actually believes. Jurisdictions that follow the common-law formulation also require the belief to be honest and objectively reasonable, as discussed earlier in connection with belief in necessity.
Each item on the list has its own reason. The first two protect the defender's life and physical integrity, and the word serious does real work in the second, because ordinary bodily harm such as a bruise or a split lip is common in quarrels, and treating it as enough would reopen the door the first tier closes. Kidnapping and compelled intercourse protect liberty and bodily autonomy. Each is grave, each is hard to undo afterward, and a person being carried off or overpowered cannot sensibly be asked to wait and learn whether the attacker also intends bodily injury. What the four share is severity: each is a harm grave enough that the law allows the defender to risk the attacker's life to prevent it.
Threats outside the list stay outside, however much they matter to the victim. A threat to property alone, a minor battery, and a verbal threat all fall short, and the earlier discussion of property claims reflects the same point, since a possessor guarding goods does not thereby face a listed harm.6
The stranger's grab is unlawful force in both scenes, and Renata's response is deadly in both, so the fact that moved the answer is whether the circumstances supported a belief in a listed harm. In the second scene nothing supports such a belief under either the actual-belief standard or the reasonable-belief standard. The harder case arises when an actor honestly but wrongly believes a listed harm is coming, which is a mistake problem taken up later in this chapter. Students also go wrong by equating any injury with qualifying harm, when the text asks for serious bodily harm.
Clearing this threshold is necessary and still leaves the defense unfinished. The same subsection withholds deadly force from an actor who provoked the encounter and from an actor who could have retreated in complete safety, and those limits apply even when the threat is a listed harm. The next part turns to the first of them, the initial aggressor.
Deadly Versus Nondeadly Force
The screen in subsection (2)(b) applies to deadly force and to nothing else, so the first move in any defensive-force problem is to sort the defender's act into one of two tiers.9 Deadly force is force the actor uses with the purpose of causing death or serious bodily harm, or force the actor knows creates a substantial risk of causing either; Section 3.11(2) of the Model Penal Code supplies that definition.10 The definition has two routes into the category. A defender who means to kill is covered by the purpose route, and a defender who means only to stop the attack but knows the method chosen carries a substantial risk of death is covered by the knowledge route, as when a firearm is aimed at the torso. Nondeadly force is everything below that line, meaning force that is neither intended nor likely to cause death or serious bodily harm.11
Threats sit on the nondeadly side of the line. A threat of deadly force, such as displaying a knife, is classed as nondeadly force.12 A verbal threat to use deadly force is likewise not deadly force so long as the defender does not intend to carry it out, a point that rests on § 3.11(2).13 The classification follows from the definition. A display or a warning aims to make the attacker back away, and by itself it creates no substantial risk of death, so it fails both routes into the deadly category.
Each tier carries its own limit. Nondeadly force may answer virtually any unlawful force, including a slap or an attempted theft, but it may never exceed what is reasonably necessary to meet the threat.14 Force beyond that point is excessive force, meaning force that is unreasonable or unnecessary under the circumstances.15 Deadly force sits behind a stricter gate and may be used only against a deadly attack.16 The Model Penal Code makes the gate concrete by listing the harms that open it in subsection (2)(b), and the next part takes up that list.17 Tort law reaches the same place through an equivalence rule: a threat of death or serious bodily harm permits equivalent force, while a threat of lesser harm calls for lesser force or the privilege is lost.18
The two tiers exist because of what self-defense protects. The defender has a right to be made safe, and the right stops once safety is achieved. When the force applied goes past what ends the danger, the excess protects the defender from nothing and only injures the other person, so the justification does not reach it and the defender becomes the wrongdoer as to the surplus. An incentive problem sits underneath as well. If a slap could be met with any force at all, the person struck first would gain a free hand to inflict whatever harm he liked on a minor offender, and a defense meant to end violence would reward the person who escalated it.
The category depends on what the force does in context, so an ordinary-looking act can change tiers. Joshua unlawfully threatens to strike Donald, and the only way Donald can avoid the blow is to push Joshua away. The push is a nondeadly response to a nondeadly assault, and it may be justified. If the push would send Joshua into oncoming traffic on a busy street, however, it is likely to cause death or serious injury, and on the common-law view Donald must then absorb the blow rather than risk the life of someone whose own threat was nondeadly.19
Only Carla's response differs between the two scenes, so the response is what moved the answer. The slap is equally unlawful in both, which shows that an unlawful attack opens the door to nondeadly force and leaves deadly force closed until a deadly threat appears. Had Malcolm followed the slap by drawing a knife, Carla would face a threat of the kind the deadly tier requires, and deadly force could become available, subject to the remaining limits on deadly force.20 Students misclassify force when they go by the name of the act, such as a push or a punch, instead of by the risk the force creates in context, which is what the definition measures.21
Classifying the force as nondeadly does not end the analysis, since the necessity ceiling still applies. Classifying it as deadly begins the more demanding inquiry that the next sub-part carries out.
Qualifying Threats
Once a defender's act has been sorted into the deadly tier, the next screen is the list in Model Penal Code § 3.04(2)(b): deadly force is not justifiable unless the actor believes it necessary to protect himself against death, serious bodily harm, kidnapping, or sexual intercourse compelled by force or threat.24 That sentence holds two requirements, and either one can fail alone. The first concerns the harm, which must be one of the four named. The second concerns the response, because the belief must be that deadly force itself is necessary against that harm. An actor who faces a grave threat but believes a warning or lesser force would end it has therefore not met the standard. The Code measures both beliefs by what the actor actually believes, and jurisdictions that follow the common-law formulation add that the belief must also be honest and objectively reasonable, a point developed earlier in connection with belief in necessity.
The four harms rest on one idea, proportion, though each has its own emphasis. Death and serious bodily harm protect the defender's life and physical integrity, and the word serious keeps out the ordinary injuries of a quarrel, such as a bruise or a split lip, which would otherwise swallow the limit the deadly tier exists to impose. Kidnapping and compelled intercourse protect liberty and bodily autonomy. Each is grave and hard or impossible to undo afterward, and a person being carried off or overpowered cannot sensibly be asked to wait and learn whether the attacker also means to injure. The law lets a defender risk the attacker's life only against a harm of that order, so the listed harms are the ones comparable in weight to the loss the response may inflict.
Jurisdictions differ in how they write the list, though not in where it leads. Where the formulation speaks only of serious bodily harm, most courts expand that phrase to cover kidnapping and forcible rape, so a threat of either permits deadly force when lesser force would not suffice.25 The Model Penal Code and a number of states name the two harms outright.26 Kidnapping and forcible rape therefore count as qualifying threats under either drafting, and the Code simply removes the need to argue that they fit inside the phrase serious bodily harm.
The opposite pole is the thief who threatens only property. When an unarmed thief tells M that he wants nothing but her belongings and that he will not hurt her, and she kills him anyway, no qualifying threat existed and the homicide is not justified, even if the property is very valuable, because the law ranks human life, including a criminal's, above property.27 The two scenes differ in what the encounter signals. The seizing of Tomas supports a belief in a listed harm, while the thief's words and unarmed state support a belief only in a loss of goods, so the answer follows the harm the circumstances pointed to, whatever fear either person felt in the moment.
The usual error is to treat any threatened injury or loss as qualifying. A minor battery, a verbal threat, and a threat to property alone all fall outside the list, however much they matter to the victim. Such threats may still justify nondeadly force, because the two tiers operate separately and nondeadly force may answer virtually any unlawful force so long as it stays within what is reasonably necessary.28 The harder case arises when an actor honestly but wrongly believes a listed harm is coming, which is a mistake problem taken up later in this chapter.
Clearing this threshold is necessary and still leaves the defense unfinished, because the same subsection goes on to withhold deadly force from an actor who provoked the encounter and from one who could have retreated in complete safety. Those limits apply even when the threat is a listed harm, and the next part turns to the first of them, the initial aggressor.