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Criminal Law
UMKC School of Law
Berger, Mark

Criminal Law


Fall 2010

Components of Crime


– Actus Reus: Objective elements of a crime that legislature has chosen to punish; may be affirmative acts or omissions.

– Mens Rea: Subjective elements required to be liable for criminal sanctions; states of mind that makes act culpable.

I. Actus Reus – Guilty Act

à ACT which CAUSES SOCIAL HARM (All 3 must be met)

à Those acts/omissions render with the appropriate mental state render the defendant liable for the crime.

A. Definitions:

1. MPC- Elements of the offense are: Conduct, Circumstance and Result

i. Conduct: Physical behavior of defendant

ii. Circumstance: An objective fact or condition that exists at the time D engages in conduct. (entering a residence at night)

iii. Result: Consequence or outcome caused by D’s conduct.

2. “Act”-An act involves physical behavior. It does not include the mental processes of planning or thinking (that is mens rea)

3. “Voluntary”- Volitional movement. Acts deemed involuntary include: spasms, seizures, asleep, sleep walking

Martin v State: Martin was not VOLUNTARILY drunk in public. He was brought there via police. Did not meet requirement.


1.§2.01 MPC- Subject to limited exceptions, a person is not guilty of a crime unless his conduct includes a voluntary act. Few statutes expressly state this, but it is treated as implicit element.

C. Material Elements

1. Every material element in every statute must be modified by one of the mental culpability states. i.e. ‘purposely destroyed a book’. Book is an attendant circumstance material element

D. Burden of Proof

1. A defendant may claim his act was involuntary. But voluntariness is an element of the crime, so the prosecution has the burden to prove it.

2. The prosecution needs to only show included a voluntary act. NOT that every act was voluntary.

Omission as Basis of Liability

· Caveats:

· Relationship status

· Statute

· Contract to provide care

· Voluntary assumption of care that isolates the individual

· Creation of peril (either by crime or tort) Jones v. State

· Duty to control the conduct of another (stop chauffeur from speeding)

· Duty of a landowner

· Must punish acts, not status Robinson v. California

Social Harms 3.04

A. Elements: The social harm of an offense, as defined by statute or at

common law, may consist of wrongful conduct, wrongful results, or both. Moreover, the

offense will contain so-called “attendant circumstance” elements.

1. “Conduct” Elements (or “Conduct” Crimes) – Some crimes establish social harm in terms of conduct, irrespective of any harmful results, e.g., driving under the influence of


2. “Result” Elements (or “Result” Crimes) – An offense may be defined in terms of a prohibited result. For example, murder is a “result” crime, because the social harm is the death of another human being, irrespective of the nature of the conduct that resulted in such death (e.g., whether the death occurred by shooting, stabbing, or poisoning).

3. Combined “Result” and “Conduct” Elements – Some offenses contain both “conduct” and “result” elements. For example, a statute may define first-degree murder as the killing of another human (the result) by means of a destructive device or explosive (the conduct).

4. Attendant Circumstances – An “attendance circumstance” is a fact or condition that must be present at the time the defendant engages in the prohibited conduct and/or causes the prohibited result that constitutes the social harm of the offense. Often an attendant circumstance is an element of the offense, e.g., the crime of burglary – the breaking and entering of the dwelling house of another at nighttime – contains an elemental attendant circumstance that the crime must occur at night.

B. Constitutional Limits – Various constitutional provisions limit the extent to which a

legislature may proscribe “social harm”. For example, the First Amendment bars a state

from criminalizing most forms of speech. Even where some social harm may occur – such

as some persons may find a given form of speech offensive – the law deems that the integrity

of constitutional rights outweighs the society’s interest in preventing the harm.

Texas v. Johnson (defacing the American flag).

II. Mens Rea- Mental State

“Elemental” Definition of “Mens Rea” – Much more prevalent today is a narrow

definition of mens rea which refers to the particular mental state set out in the definition of

an offense. In this sense, the specific mens rea is an element of the crime.

§ 5.02 Specific Mens Rea Requirements

A. Intent – A person “intentionally” ca

t cite a specific mens rea requirement, knowingly is the default one.

i. United States v. Staples

§ 5.05 Model Penal Code

• discards the common law distinction between “general intent” and “specific intent”;

• limits mens rea to four terms: “purposely”; “knowingly”; “recklessly”; and


• requires application of mens rea to every material element of a crime, including

affirmative defenses.

A. Mens Rea Terms

1. “Purposely” – In the context of a result or conduct, a person acts “purposely” if it is

his “conscious object to engage in conduct of that nature or to cause such a result.” [MPC §

2.02(2)(a)(i)] A person acts “purposely” with respect to attendant circumstances if he “is

aware of the existence of such circumstances or he believes or hopes that they exist.”

2. “Knowingly” – A result is “knowingly” caused if the defendant “is aware that it is

practically certain that his conduct will cause such a result.” [MPC § 2.02(2)(b)(ii)] With

“attendant circumstances” and “conduct” elements, one acts “knowingly” if he is “aware that

his conduct is of that nature or that such [attendant] circumstances exist. Furthermore, the

Code states that knowledge is established, if “a person is aware of a high probability of . . .

[the attendant circumstance’s] existence, unless he actually believes that it does not exist.”

3. “Recklessly” and “Negligently” – The Code provides that a person acts “recklessly” if

he “consciously disregards a substantial and unjustified risk that the material element exists

or will result from his conduct.” A risk is “substantial and unjustifiable” if “considering the

nature and purpose of the defendant’s conduct and the circumstances known to him, its

disregard involves a gross deviation from the standard of conduct that a law-abiding person

would observe in the actor’s situation.”