Also known as:defensive force justification · self-defense · justification defense · use of force justification
Written by attorneys · grounded in primary & secondary sources — see below
A category of justification defenses that permit an actor to respond with force to an aggressor's threat of unjustified harm to a protected interest. The responsive conduct must be necessary to protect the interest and proportional to the harm threatened.
Sources & Authorities· 6 primary sources
Select any source to read its text and confirm it supports the definition.
Cases
Common Law
Restatements
Casebooks
How it applies
Common Examples
6
Homeowner Challenges Handgun Ban
Deanna Davenport keeps a handgun in her apartment for protection after repeated break-ins. City police cite her for violating an ordinance that bans all handguns in residences and requires other firearms to remain disassembled. She sues, arguing the rules leave her unable to access a functional firearm when an intruder enters at night. The court invalidates the ordinance because it eliminates the practical ability to use arms for immediate self-defense in the home.
Imperfect Self-Defense Reduces Charge
Diego Duarte sees an assailant raise a knife during a street fight and fires his gun, killing the attacker. Duarte honestly believed deadly force was required, but the belief was unreasonable because the attacker was already backing away. The jurisdiction recognizes imperfect self-defense. Duarte's murder charge is reduced to voluntary manslaughter.
Tenant Refuses to Comply with Command
Darius Dixon faces an intruder who orders him to hand over his wallet at gunpoint. Dixon could safely retreat through a back door but stands his ground and uses nondeadly force to repel the attack. The intruder sues for battery. Dixon prevails because he was not required to give up his right to remain in his home or comply with the unlawful demand.
Firm Uses Client Files in Malpractice Suit
Darrell Duncan sues his former law firm for overbilling after a contentious divorce representation. The firm obtains and discloses client communications to defend the fee claim. Duncan moves to strike the evidence under attorney-client privilege. The court denies the motion because the client placed the representation at issue by alleging inadequate performance.
Homeowner Uses Excessive Force
Dylan Duffy confronts a trespasser who shoves him once. Duffy responds by striking the trespasser repeatedly with a baseball bat after the threat has ended. The trespasser sues for battery. Duffy is liable for the excess force because the additional blows exceeded what he reasonably believed necessary for protection.
Threat Creates Apprehension Only
Demetrius Douglas points an unloaded gun at an aggressor who is advancing with a knife. Douglas intends only to make the aggressor believe he will be shot, causing the aggressor to stop. The aggressor sues for assault. Douglas is privileged because his act was intended solely to create apprehension and did not exceed what was reasonably believed necessary.
Common questions
Frequently Asked
6
What are the core requirements for a defensive force justification to apply?+
The defense requires triggering conditions consisting of an aggressor's threat of unjustified harm to a protected interest. The response must then be both necessary to protect that interest and proportional to the harm threatened.
Does an honest but unreasonable belief in the need for deadly force ever reduce murder to voluntary manslaughter?+
In some jurisdictions an honest but unreasonable belief that deadly force was necessary in self-defense mitigates murder to voluntary manslaughter under the doctrine of imperfect self-defense.
Must a defender retreat before using nondeadly force?
+
A defender need not retreat or comply with an unlawful command when using nondeadly force if doing so would require giving up a right or privilege the defender is under no duty to surrender.
When may a law firm disclose client communications to defend itself?+
A law firm may use client communications and work product when the client has placed the representation at issue by alleging malpractice or overbilling, because the self-defense exception to privilege then applies.
What limits the amount of force a defender may use?+
A defender may not use any means of self-defense intended or likely to cause bodily harm in excess of what the defender correctly or reasonably believes necessary for protection.
Is a defender privileged to create apprehension of excessive harm?+
A defender may be privileged to create an apprehension of harmful contact even if the threatened harm would exceed what is actually privileged, provided the act is intended only to produce that apprehension and is reasonably believed likely to do no more.
could constitutionally be placed on the defendant. We explained that Mullaney "is not a decision that the prosecution must prove beyond a reasonable doubt every fact, the absence of which…
of another, were automatically executed. A. Higginbotham, In the Matter of Color: Race in the American Legal Process 256 (1978). By the time of the Civil War, a dual system…
and struck down a District of Columbia law that banned the possession of handguns in the home. Chicago (hereinafter City) and the village of Oak Park, a Chicago suburb, have laws…
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