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Criminal Law
UMKC School of Law
O'Brien, Sean D.

Criminal Law


Fall 2011

3 Ingredients to Actus Reus:

1.) Voluntary Act

2.) Cause

3.) Social Harm

· People are not legally responsible for their thoughts, unless accompanied by an illegal action.

Voluntary Act (2 components)

1.) Act: Physical act, such as pulling a trigger, talking, etc. (3 aspects to note)

a. Sometimes a person can move, but not act. Like if someone grabs your arm and swings it into someone.

b. “Act” does not apply to the result of the act.

c. The act must be voluntary.

2.) Voluntary: Not used in actus reus like in defenses. Duress and insanity do not apply.

· Most acts are voluntary.

· EXCEPTION: Involuntary acts: spasms, reflexes, epileptic seizures, and bodily movements when the actor is unconscious or asleep.

· Definition: Movement of the body which follows our volition.

o Volition:


Genovese case from Psych. Woman stabbed while everyone watched. Omission ex.

· Point of omission is to exonerate people who are guilty of moral indifference. Genovese ex.

· MPC: A person is not guilty of any offense unless his conduct “includes a voluntary act or the omission to perform an act of which he is physically capable.”

o Liability based on omission is permitted in two circumstances:

§ 1.) If the law defining the offense provides for it.

§ 2.) If the duty to act “is otherwise imposed by law.”

· The latter arises under civil law, such as torts or contract law.

Omission Liability


· Breach of a duty to Act.

· “Duty” arises from relationship.

· Defendant must have the capacity to perform.

Jones v. US (p.192): Didn’t feed the baby to death.

-The burden of proof is on the state.

Elements to form a Legal Duty:

1.) Statute: Any statutes stating the legal duty.

2.) Relationship: Mother/Father…so on.

3.) Contractual: A contract in which you agree for the care of the child.

4.) Assumed Duty: Duty that is assumed. This can lead to secluding others from helping the people.

5.) Secluded:

***The main thing helping the omission of the duty is the fact that the parents are present.***

Almost all common law crimes are gone. Now they are all punishable by statutes.

When it is sufficiently culpable that you need to act it is the line the law draws, not a moral line.

Duty otherwise imposed by law.


· To victim

· To circumstances or event

Distinguishing acts and omissions:

· Passive Euthanasia v. Active Euthanasia

o Discounting care is not an “act” (Cruzan)

o Administering lethal gas is an act (Kevorkian), but see Independent Intervening Cause

Barber v. Superior Court (P.208): Doctors Killing a Vegetable

Issue: Is it murder when the victim has no chance of living and the family requests the person let die.

Holding: No. The family wanted to let him die, so they wanted what was best for the patient.

· -The physician has no duty to continue care if the treatments are ineffective.

· -The court decides that this was a circumstance was an omission of duty.

o -The affirmative act would be to continue to administer the actions to help him live.

o -The pulling of the plug is the omission. The court defines the pulling of the plug as an omission, not an act, to get around a causation.

· -The duty to continue treatment is what sets this apart from making this an illegal act. Since the family wanted this to happen and the patient had no chance to live, there was no duty.

Mens Rea: Culpable state of mind.

Ø Must have intent.

Common law intent: The person intentionally causes the social harm of an offense if:

1.) It is his desire (i.e., his conscious objective) to cause the social harm of an offense; or

2.) He acts with knowledge that the social harm is virtually certain to occur as a result of his conduct.

**Transferred Intent: Intent transfers…**

Specific Intent v. General Intent

Specific Intent:

1.) Includes an intent or purpose to do some future act, or to achieve some further consequence (i.e., a special motive for the conduct), beyond the conduct or result that constitutes the actus reus of the offense, or

2.) Provides that the actor must be aware of statutory attendant circumstances.

**An offense that does not contain one of these features is termed “general intent”**

**Ex: Burglary requires the actus reus of entering the dwelling of another at nighttime; he need not commit a felony inside to be convicted. The requisite mens rea, therefore, pertains to a planned future act (Commission of a felony) that is not part of the actus reus. Consequently, common law burglary is a specific-intent offense.

**Ex(2): Larceny requires a trespasser to take something with intention of permanently depriving the person of his property. This makes it specific intent as well.

**Ex(3) General intent: Battery, there is no specific intent in the description of the crime, so it is general.

MPC § 2.02

· Subsection one provides that, except in the case of offenses characterized as “violations”, a person may not be convicted unless “he acted purposely, knowingly, recklessly or negligently, as the law may require, with respect to each material element of the offense.”

Pages 140-144 for each element broken down, if needed.

Strict Liability

There must be a guilty mind EXCEPT:

1.) Dealing with the public health and safety.

2.) Light Punishment?-for most strict liabilities there is a light punishment. The harsher the punishment, the more likely the need for a mens rea is not needed because the extent that the crime is despicable.

Ex. of non-public health and safety related strict liability: Statutory rape. No mens rea needed to be guilty.

· These differ from public health in the punishment being more severe

· Non-public health and safety typically involve conduct malum in se (inherently wrongful).

Morisette v. US (P.250) Bomb case stealer


Is mens rea (guilty mind) required in the crime which the defendant is being charged with?


Yes. In the common law, guilty mind was a requirement. But recently, many statues have been passed by states concerning minor crimes where guilty intent is not required. But the crime in question, the court held, is larceny and this should not be considered as one of those non-intent crimes. The court ruled that since the defendant did not have mens rea, he cannot be charged with larceny. The ruling of trial court was reversed.

Mens Rea: 1.)Knowingly 2.)converted 3.)government property.

The defendant wants the jury to be instructed that he knowingly converted the property, having a good faith belief that the property was abandoned.

Plaintiff just has to prove that the defendant knowingly took possession of the property.

Strict liability is strongly disfavored by common law because they run the risk of the prosecuting innocent people.

-If it not applied is certain parameters.

Court insists on certain areas for strict liability:

1.) Public safety and welfare.

2.) Not a felony.

-If the punishment is a felony, it is less likely to be a strict liability offense. The more severe the punishment, the less likely strict liability will be imposed.

*It could be not abandoned property, and Morisette could

the law defining the offense.

§ Sometimes called “reasonable reliance” or “entrapment by estoppel” doctrine. (p.172-173 for more info., if needed.)

4.) Fair Notice and the Lambert Principle: p.174

Lambert v. California (p.282) Non registered in LA and gets fined.

Issue: Should the defendant’s ignorance of registering law be used as a defense?

Holding: Yes

Legal Reasoning: The defendant’s failure to register was a “wholly passive” act. The defendant was not given any notice and she was not aware of any such statute. The statute also did not serve any obvious purpose which could have made it popular among the public. The court held that punishing a person for a statue of which she had no actual knowledge or “probability of knowledge” would be too severe for the society to accept. The defendant’s conviction was reversed.

-Due process clause used to find the holding. NO person may be denied blah blah blah…

-The city must show that they had notice given of the regulation.

-Without the notice there is no duty.

Ignorance or Mistake that Negates Mens Rea:

1.) General Approach:

a. A person can be aware of the crimes, but unaware that they are committing the crime at the time.

i. Ex: Mechanic can withhold you vehicle if you don’t pay, and if you come and take it back you are guilty of larceny.

2.) Specific Intent Offenses:

a. A different-law mistake, whether reasonable or unreasonable, is a defense in the prosecution of a specific intent in the prosecuted offense. This doctrine parallels the rule relating to mistakes-of-fact in the prosecution of specific-intent crimes.

i. Ex: The larceny example above, since the person taking the car back did not know that the car was not her property when she was taking it back, she lacked the mens rea requires to be convicted of larceny.

Cheek v. US (p.275) No paying of taxes by pilot.

Issue: Can the defendant use the belief that wages are not income as a defense?

Holding: Yes.

Legal Reasoning:

The court ruled that honest beliefs of the defendant do not have to be objectively reasonable and as long as the defendant honestly does something without the guilty mind, he should be allowed to use his beliefs a defense. The court further held that the defendant in the current case was aware of the fact that he had to pay taxes and he, as a matter of fact, had paid his taxes in the past. His argument that tax laws are unconstitutional is not the innocent mistake which can be used as a defense. The defendant could have paid his taxes and could have challenged the constitutionality of the tax laws in the court, but he did not do so. So the defendant’s unconstitutional argument is not an innocent mistake and cannot be used as a defense. But the court did hold that the defendant’s belief that wages are not income can be introduced as defense and it is up to the jury to decide whether these beliefs are honest. The court remanded the case for further proceedings consistent with the decision of this court.