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Criminal Law
University of Kentucky School of Law
Lollar, Cortney E.

Criminal Law Lollar Fall 2014

Mens rea

MPC § 2.02

Purposely (Intentionally)

1) Conduct or Result: It is his conscious object to cause the result or engage in the conduct.

2) Attendant circumstance: He is aware of the existence of the circumstance or he believes or hopes that it exists.

a) This has no respect for probability but is about attitude.


1) Result: The person is aware that the result is practically certain to occur.

2) Attendant Circumstance: He is aware the circumstance exists or of a high probability that they exist.

a) This speaks to near 100% certainty of probability or at least a high probability

b) This could also be said to be acting willfully.


1) Result or Circumstance: Conscious disregard of a substantial and unjustifiable risk that the material element exists or will result from his conduct. This involves a “gross deviation from the standard of care that a reasonable person would observe in the actor’s situation.”


1) The person should be aware of a substantial and unjustifiable risk and the risk constitutes a gross deviation from the standard of care that a reasonable person would observe in the actor’s situation.

(i) In terms of probability, this is the same as recklessness but the attitude is different. Here, you simply should have been aware but you were not.


a) Intoxication (Excuse): Can be from the ingestion of any foreign substance including drugs, alcohol, or medication.

(i) Common Law: Voluntary intoxication can challenge mens rea for specific-intent crimes but not general.

(ii) Model Penal Code:

(1) 2.08: Voluntary intoxication can be used to challenge mens rea for purpose and knowing (State v. Cameron) but not for recklessness or negligence. If you consciously disregarded or failed to perceive because of the intoxication, it is not a defense.

(a) If you fail to perceive a risk due to intoxication but you should have been aware, you can be convicted of recklessness under 2.08(2). The recklessness of becoming voluntarily intoxicated can transfer to the actual crime.

Involuntary Intoxication:

(2) How it can occur:

(a) Coercion

(b) Mistake

(c) Reaction to prescribed medication

(d) Pathological intoxication which is unanticipated in degree

(3) MPC allows involuntary to negate any mental state (2.08(1)).

(4) Temporary insanity from voluntary intoxication is admissible and can be used as an excuse defense.

Mistake of Fact

Common Law

1) The defense must raise the defense but the burden in on the government to prove that the mens rea existed despite mistake of fact

2) Specific Intent: A mistake of fact will exculpate for a specific intent crime if it negates the specific-intent element of the offense. This is true even if it is an unreasonable mistake of fact

a. Example: Taking property that you think was abandoned. Larceny requires that you take with the intent to steal so acting recklessly or negligently will not suffice. You must lack the mens rea in the specific elemental sense, not the broad culpability sense.

3) General Intent: A person is not guilty if the act was done with a morally blameless state of mind due to mistake. There was no mens rea in the broad culpability sense. Here, however, an unreasonable mistake of face will not exculpate.

Strict Liability: mistake of fact will not exculpate

Mistake of Law

1) Common Law and The MPC are almost the same here.

a) In general, knowledge of the law is not an element of an offense. Even a reasonabl

requirement provides a clear line between bad thinkers and bad actors and the act itself is evidence of bad intent.

(iii) Crimes which are hard to detect are usually the ones in which the act requirement is watered down the most i.e. drugs or burglary. In these cases, possession of something may be enough whereas in other cases, it is not enough (Proctor v. State).

(1) MPC §2.01(1): To qualify as conduct, behavior must be an act and it must be voluntary. It can also be an omission to perform an act of which one is physically capable. Thus, doing nothing can be an act and it can even be punished.

b) Omissions: Generally a person is not guilty of a crime for failing to act, even if such failure permits harm to occur to another, and even if the person could act at no risk to personal safety.

(i) MPC §2.01(3): There are two exceptions to the general rule that an omission cannot be a crime.

(1) Express imposition by a staute requiring a person to perform apecified acts (a).

(a) Example: You must pay your taxes.

(2) The duty is “otherwise imposed by law” in (b). This allows common law duties to creep into the equation. Traditional common law duties can be imposed by:

(a) Relationship or Status:

1. Ex. Parent/child, spouse, master/servant

(b) Contract or implied contract

1. Ex. Babysitter (Jones v. US)

(c) Voluntary assumption of care

1. One who assumes the care of another must continue to assist if the omission would place the person in a worse position than if they good Samaritan had never intervened at all.