Actus Reus — Voluntary Acts
Theories of Punishment
Omissions and Possession
Mens Rea
Mistake, Strict Liability, and Causation
100

The “act” requirement of a crime.

What is actus reus?

  • Actus reus means the physical component of a crime.
  • It includes the acts involved in the crime.
  • It may also include causation of a result.
  • A crime generally requires both actus reus and mens rea.
100

The punishment theory focused on giving offenders what they deserve.

What is retribution?

  • Retribution is backward-looking.
  • It asks whether the defendant deserves punishment.
  • It is not mainly concerned with social effects like reducing future crime.
  • It is useful for thinking about proportionality: the punishment should fit the wrong.
100

The two things required for an omission to satisfy actus reus.

What are a legal duty and a failure to act?

  • An omission is a failure to do something.
  • Usually, people are not criminally liable for failing to act.
  • Liability requires a legal duty.
  • Once a legal duty exists, failure to perform that duty can substitute for a voluntary act.
100

The four MPC mental states.

What are purpose, knowledge, recklessness, and negligence?

  • Purpose: subjective objective to engage in conduct or cause a result.
  • Knowledge: subjective awareness.
  • Recklessness: subjective disregard of a substantial and unjustifiable risk.
  • Negligence: failure to perceive a substantial and unjustifiable risk that a reasonable person would perceive. 
100

The mistake defense that applies when the mistake negates mens rea.

What is mistake of fact?

  • Mistake of fact is a defense if it negates the required mental state.
  • For subjective mental states like purpose, knowledge, and recklessness, the mistake can be unreasonable.
  • For negligence, the mistake must be reasonable.
  • The key question is whether the mistake defeats the mens rea required for the element.
200

The three kinds of crime elements.

What are conduct, circumstances, and results?

  • Conduct: what the defendant does.
  • Circumstances: facts that must exist when the conduct occurs.
  • Results: the outcome caused by the defendant’s conduct.
  • Example: in homicide, the conduct may be shooting, the circumstance may involve the victim being a human being, and the result is death.
200

The punishment theory that balances the social costs and benefits of punishment.

What is utilitarianism?

  • Utilitarianism is forward-looking.
  • It asks what effect punishment will have on society.
  • Benefits may include reduced crime.
  • Costs may include imprisonment costs, harm to families, and wasted resources.
  • Punishment is justified only if the social benefits outweigh the costs.
200

The major types of legal duties that can make an omission criminal.

What are statutory duties, status relationships, contractual/professional duties, common-law duties, and tort-law duties?

  • Statutory/written law: a law requires action.
  • Status relationships: spouse-spouse, parent-child.
  • Contractual/professional relationships: doctor-patient, lifeguard-swimmer, caregiver-dependent person.
  • Common law: voluntary assumption of care plus seclusion, or creation of peril.
  • Tort law: civil-law duties may sometimes matter. 
200

The MPC default mental state when a statute is silent.

What is recklessness?

  • If the statute does not specify culpability, MPC generally defaults to recklessness.
  • Recklessness requires subjective awareness of risk.
  • The risk must be substantial and unjustifiable.
  • The defendant’s disregard must be a gross deviation from what a law-abiding person would do. 
200

The four main exceptions to the rule that mistake of law is usually not an excuse.

What are official statement, mistake of other law, no notice, and element exceptions?

  • Official statement: reasonable reliance on an official legal interpretation.
  • Mistake of other law: misunderstanding a non-criminal legal circumstance; treated like mistake of fact.
  • No notice: rare situation where the defendant could not know about the criminal prohibition.
  • Element: the law itself makes ignorance or mistake of law relevant. 
300

The four tests for a voluntary act.

What are Martin, MPC, Newman, and Last Act?

  • Martin: All conduct must be voluntary.
  • MPC: The conduct must “include” a voluntary act.
  • Newman: MPC test plus foreseeability.
  • Last Act: The final act that makes the conduct criminal must be voluntary.
300

The theory of punishment that creates incentives for both society and individuals not to commit crimes.

What is deterrence?

  • Deterrence is a utilitarian theory.
  • General deterrence discourages the public from committing crimes.
  • Specific deterrence discourages the individual defendant from reoffending.
  • It works by making crime seem less attractive because of the threat of punishment.


300

The type of possession based on known direct physical control.

What is actual possession?

  • Actual possession means the defendant physically controls the item.
  • The control must be known.
  • Example: drugs in the defendant’s hand or pocket.
  • Momentary touching alone is usually not enough. 
300

The three major types of common-law specific intent.

What are intent to commit a future act, intent to achieve a specific result, and knowledge of attendant circumstances?

  • Future act: burglary requires intent to commit a felony inside.
  • Specific result: larceny requires intent to permanently deprive.
  • Attendant circumstances: receiving stolen property requires knowledge that the property is stolen.
  • Specific intent usually requires a more particular mental state than general intent. 
300

The two major categories of strict-liability offenses.

What are public welfare offenses and morality offenses?

  • Usually, courts presume every material element requires some culpable mental state.
  • Public welfare offenses: regulatory offenses, often involving dangerous or heavily regulated activities.
  • Relevant factors include the nature of the activity, the nature of the element, and severity of punishment.
  • Morality offenses: examples include statutory rape, bigamy, and felony murder. 
400

The voluntary-act test that asks whether the defendant’s conduct includes at least one voluntary act.

What is the MPC test?

  • The MPC does not require every part of the conduct to be voluntary.
  • It only requires that the conduct include a voluntary act.
  • This is broader than Martin.
  • If there is at least one voluntary act within the relevant conduct, the act requirement may be satisfied.
400

The theory of punishment that protects society by removing dangerous people from the community.

What is incapacitation?

  • Incapacitation prevents crime by physically restricting the offender.
  • Prison is the clearest example.
  • The focus is not on moral blame or rehabilitation.
  • The idea is: if the person is locked up, they cannot commit more crimes in society.
400

The type of possession based on power and intention to exercise dominion and control.

What is constructive possession?

  • Constructive possession does not require physical holding.
  • The defendant must knowingly have power over the item.
  • The defendant must also intend to exercise control over it.
  • Items found in someone’s house often support constructive possession, though proof can still be contested. 
400

The common-law general intent defaults for result, conduct, and circumstance elements.

What are recklessness for result, intent for conduct, and negligence for circumstances?

  • Result elements: default to recklessness.
  • Conduct elements: require intent to do the physical acts.
  • Circumstance elements: default to negligence, based on mistake-of-fact doctrine.
  • These defaults matter when the statute does not clearly define the required mental state. 
400

The two kinds of actual causation.

What are but-for causation and substantial-factor causation?

  • But-for causation: but for the defendant’s conduct, the result would not have happened.
  • Substantial-factor causation: used when multiple causes contribute to the result.
  • Actual causation asks whether the defendant’s conduct factually contributed to the harm.
  • It is separate from proximate causation.
500

The voluntary-act test that combines the MPC approach with foreseeability.

What is Newman?

  • Newman starts with the MPC rule.
  • The conduct must include a voluntary act.
  • But there is also a foreseeability requirement.
  • The defendant’s voluntary conduct must make the later criminal conduct foreseeable.
500

The theory of punishment that treats crime like an illness or condition that can be corrected.

What is rehabilitation?

  • Rehabilitation tries to reform the offender.
  • It may involve treatment, education, counseling, job training, or therapy.
  • The goal is to reduce future crime by changing the offender.
  • It is forward-looking and utilitarian in structure. 
500

The possession rule that replaces the voluntary-act requirement when someone knowingly receives or controls an item long enough to get rid of it.

What is the possession substitute for a voluntary act?

  • Possession can satisfy actus reus.
  • The person must knowingly procure or receive the thing possessed.
  • Alternatively, after acquiring control, the person must be aware of the control.
  • They must have control for enough time to dispose of it or terminate control.
  • Possession can be actual, constructive, or joint.
500

The two mens rea caveats involving accidental victims and deliberate avoidance of knowledge.

What are transferred intent and willful blindness?

  • Transferred intent: intent transfers to additional or substitute accidental victims.
  • Intent does not transfer to different harms.
  • MPC willful blindness: knowledge is satisfied by awareness of a high probability, unless the defendant actually believes the fact does not exist.
  • Common-law willful blindness: defendant subjectively believes there is a high probability and deliberately avoids learning the truth.
500

The major common-law proximate-causation factors.

What are foreseeability, responsive intervention, coincidental intervention, apparent safety, voluntary human intervention, omissions, intended consequences, and de minimis contribution?

  • Foreseeability: foreseeable results are more likely proximate.
  • Responsive intervention: usually does not break the chain unless abnormal or unforeseeable.
  • Coincidental intervention: usually breaks the chain unless foreseeable.
  • Apparent safety: usually breaks the chain if the victim reaches apparent safety.
  • Voluntary human intervention: deliberate choices are more likely to break the chain.
  • Omissions: do not break the chain.
  • Intended consequences: if the intended outcome happens in the generally intended way, the chain usually remains intact.
  • De minimis contribution: a minor but-for cause may not be a proximate cause.