General principles - Justification and excuse

Learning Outcomes

This article examines the concepts of justification and excuse in Criminal Law. It details specific defenses such as self-defense, necessity, duress, and mistake of fact/law. After reading this article, you will be able to distinguish between justification and excuse, analyze the elements required for each defense, understand the limitations on their use (especially regarding the use of deadly force), and apply these principles to MBE fact patterns involving potential defenses to criminal liability.

MBE Syllabus

For the MBE, you are required to understand the fundamental principles distinguishing defenses that justify conduct from those that excuse it. This includes knowing the specific elements and limitations of major defenses. You should be prepared to:

• Differentiate between justification defenses (conduct was not wrongful under the circumstances) and excuse defenses (actor is not blameworthy).
• Analyze the elements of self-defense, including the requirements for non-deadly and deadly force, the aggressor rule, and retreat doctrines.
• Understand the requirements for defense of others and defense of property.
• Apply the elements of the necessity defense (choice of evils).
• Analyze the requirements for the duress defense and its limitations.
• Evaluate defenses based on mistake of fact and mistake of law, considering the mental state required for the crime.
• Understand the impact of intoxication (voluntary and involuntary) as a potential excuse.

Test Your Knowledge

Attempt these questions before reading this article. If you find some difficult or cannot remember the answers, remember to look more closely at that area during your revision.

1. Which of the following defenses, if successful, results in an acquittal because the defendant's conduct, although criminal on its face, was socially acceptable under the circumstances?
   1. Insanity
   2. Duress
   3. Necessity
   4. Mistake of fact
2. A defendant uses non-deadly force against another person. Under the principles of self-defense, the defendant's actions are justified if:
   1. The defendant was the initial aggressor but later withdrew.
   2. The defendant reasonably believed such force was necessary to protect himself from imminent unlawful force.
   3. The other person had previously threatened the defendant.
   4. The defendant honestly but unreasonably believed force was necessary.
3. Voluntary intoxication may serve as a defense to which type of crime?
   1. Strict liability offenses
   2. General intent crimes
   3. Specific intent crimes
   4. Malice crimes

Introduction

Criminal liability requires both an actus reus (a guilty act or omission) and a mens rea (a guilty mind), occurring concurrently, plus causation and harm. Even when the prosecution can establish these elements, a defendant may avoid conviction if their conduct is justified or excused.

Justification defenses focus on the act itself. The defendant effectively admits committing the act but argues that the act was not wrongful under the circumstances. Examples include self-defense and necessity. If a defendant's conduct is justified, it means that anyone else in the same situation would also have been entitled to act in the same way.

Excuse defenses focus on the actor. The defendant admits the act was wrongful but argues that he should not be held criminally responsible due to some personal disability or condition at the time of the act. Examples include insanity and duress. An excuse is personal to the defendant.

Key Term: Justification Defenses Defenses where the defendant accepts responsibility for the act but argues the act was permissible under the circumstances (e.g., self-defense, necessity).

Key Term: Excuse Defenses Defenses where the defendant admits the act was wrong but argues he is not criminally responsible due to a lack of capacity or culpability (e.g., insanity, duress).

Justification Defenses

Justification defenses render otherwise criminal conduct lawful.

Self-Defense

A person is justified in using force upon another person when and to the extent that he reasonably believes such force is necessary to defend himself from what he reasonably believes to be the use or imminent use of unlawful force by such other person.

Key Term: Self-Defense The right to use reasonable force to protect oneself from the imminent use of unlawful force by another.

Non-Deadly Force

An individual who is not the aggressor may use such non-deadly force as he reasonably believes is necessary to protect himself from imminent unlawful force. There is no duty to retreat before using non-deadly force.

Deadly Force

Deadly force is force likely to cause death or serious bodily injury. An individual may use deadly force in self-defense only if he reasonably believes that he is threatened with imminent death or great bodily harm.

Key Term: Deadly Force Force likely to cause death or serious bodily harm.

Key Term: Non-Deadly Force Force not likely to cause death or serious bodily harm.

Retreat: There is no duty to retreat before using deadly force under the majority rule. A significant minority of states require retreat before using deadly force if it can be done safely, unless the actor is in his own home (the "castle doctrine").

Aggressor Rule: Generally, the initial aggressor (one who first uses or threatens force) cannot claim self-defense. However, an aggressor can regain the right to use self-defense if:

1. He effectively withdraws from the confrontation and communicates his desire to do so; OR
2. The victim suddenly escalates a minor fight into one involving deadly force without giving the aggressor a chance to withdraw.

Mistake: A reasonable mistake as to the existence of the danger allows the defense. An unreasonable mistake does not, although it might reduce the charge (e.g., imperfect self-defense reducing murder to manslaughter).

Defense of Others

A person is justified in using force to defend another person if he reasonably believes that the person he is defending has the legal right to use force in their own defense. The amount of force used must be reasonable under the circumstances.

• Majority View: No special relationship is required.
• Mistake: A reasonable mistake as to the other person's right to use self-defense is permitted.

Defense of Property

Defense of Dwelling: Non-deadly force may be used if reasonably believed necessary to prevent or terminate an unlawful entry or attack on one's dwelling. Deadly force may be used only to prevent a violent entry if the person reasonably believes the force is necessary to prevent personal attack or to prevent entry by someone intending to commit a felony inside.

Defense of Other Property: Non-deadly force may be used to defend property in one's possession from unlawful interference if reasonably believed necessary to prevent imminent interference. Deadly force may never be used solely to defend property. A request to desist is usually required first. Force cannot be used to regain property wrongfully taken unless in immediate pursuit.

Necessity (Choice of Evils)

Conduct that is otherwise criminal is justifiable if the defendant reasonably believed that the conduct was necessary to avoid an imminent and greater injury to society than that involved in the crime itself.

• Objective Test: The belief must be reasonable.
• Harm Avoided Must Outweigh Harm Caused: The defendant must choose the "lesser of two evils."
• No Fault: The defense is unavailable if the defendant created the situation requiring the choice.
• Limitation: Generally not available as a defense to homicide.
• Source: Traditionally applied to harms caused by natural forces, but modernly can apply to other situations.

Key Term: Necessity A justification defense applicable when the defendant reasonably believed his criminal conduct was necessary to avoid a greater harm.

Worked Example 1.1

David is hiking when a sudden blizzard traps him in the mountains. Freezing and lost, he breaks into an unoccupied cabin to take shelter and finds emergency supplies, which he consumes. The cabin owner later prosecutes David for burglary and larceny. David asserts the defense of necessity. Is David likely to succeed?

Answer: Yes, David is likely to succeed with the necessity defense. He reasonably believed breaking into the cabin (burglary) and consuming supplies (larceny) were necessary to avoid a greater harm (death from exposure/starvation). The harm caused (property damage/loss) is outweighed by the harm avoided (loss of life). He did not cause the blizzard. This defense justifies his actions under the circumstances. (Note: He may still be liable in tort for damage to the cabin/supplies).

Excuse Defenses

Excuse defenses concede the act was wrongful but claim the actor should not be held responsible.

Duress

A defendant's conduct is excused if it was the result of a threat of imminent death or serious bodily injury to himself or another, and the defendant reasonably believed he (or the third party) was in imminent danger.

• Human Threat: Unlike necessity, the threat must originate from another human being.
• Limitation: Duress is not a defense to intentional homicide.
• No Fault: The defendant must not be at fault in creating the situation producing the duress.

Key Term: Duress An excuse defense applicable when the defendant was coerced into committing a crime by the threat of imminent death or serious bodily injury to himself or a third person.

Mistake of Fact

A mistake of fact exists when the defendant misunderstands some fact that negates an element of the crime.

• Specific Intent Crimes: Any mistake of fact (reasonable or unreasonable) that negates the specific intent is a defense.
• General Intent/Malice Crimes: Only a reasonable mistake of fact is a defense.
• Strict Liability Crimes: Mistake of fact is never a defense.

Worked Example 1.2

Clara takes an umbrella from a restaurant stand, honestly but unreasonably believing it is hers. The umbrella actually belongs to Ben. Clara is charged with larceny (a specific intent crime requiring intent to permanently deprive another of their property). Is mistake of fact a defense?

Answer: Yes. Larceny requires the specific intent to permanently deprive another person of their property. Clara's mistake, even though unreasonable, negates this specific intent because she believed the property was hers. For specific intent crimes, any mistake of fact, reasonable or not, is a defense if it negates the required intent.

Mistake of Law

Generally, ignorance or mistake of law is not a defense. People are presumed to know the law.

• Exceptions:
  • The statute was not published or made reasonably available.
  • Reasonable reliance on a statute or judicial decision later overturned.
  • Reasonable reliance on official interpretation or advice (e.g., from Attorney General, but not private counsel).
  • Mistake of law negates specific intent if knowledge of the law is an element of the crime (rare).

Intoxication

Intoxication relates to disturbances caused by substances like alcohol or drugs.

• Voluntary Intoxication: Results from the intentional taking of a substance known to be intoxicating, without duress. It is a defense only to specific intent crimes (and no other crime) if the intoxication prevents the defendant from forming the required specific intent. It is not a defense if the defendant became intoxicated for the purpose of committing the crime.
• Involuntary Intoxication: Results from taking a substance without knowledge of its nature, under direct duress, or pursuant to medical advice while unaware of its intoxicating effect. It is treated like insanity and is a defense to all crimes if the intoxication renders the defendant unable to meet the applicable standard for insanity in the jurisdiction.

Exam Warning

Distinguish carefully between Necessity and Duress. Necessity involves choosing the lesser of two evils, often arising from natural forces, and is a justification. Duress involves coercion by human threat, excusing the conduct, and is generally not a defense to homicide.

Key Point Checklist

This article has covered the following key knowledge points:

• Justification defenses (e.g., self-defense, necessity) make the act permissible.
• Excuse defenses (e.g., duress, insanity) absolve the actor due to lack of blame.
• Self-defense requires reasonable belief of imminent unlawful force; deadly force is limited to threats of death/serious bodily harm. Retreat rules vary.
• Defense of others generally follows self-defense rules applied to the person aided.
• Defense of property allows reasonable non-deadly force; deadly force is prohibited.
• Necessity requires avoiding a greater harm; not a defense to homicide.
• Duress requires threat of imminent death/serious bodily harm; not a defense to homicide.
• Mistake of fact is a defense if it negates the required mental state (reasonableness matters for general intent/malice).
• Mistake of law is generally not a defense.
• Voluntary intoxication is a defense only to specific intent crimes if intent negated.
• Involuntary intoxication is a defense to all crimes if the insanity standard is met.

Key Terms and Concepts

• Justification Defenses
• Excuse Defenses
• Self-Defense
• Deadly Force
• Non-Deadly Force
• Necessity
• Duress