This section covers the general principles of criminal liability. Conduct that includes a voluntary act and a culpable mental state is closely examined. Accessory liability and general defenses are also discussed.


I. What are the elements of a crime? Each code crime states its elements, but to understand principles, let's generalize.


Alternative Definition of Crime

1. An act or omission

2. Prohibited by law to protect the public

3. The violation of which is prosecuted by the state and is punishable by fine, incarceration or other restriction of liberty or some combo thereof.


B. General Elements of Crime. Every crime requires certain generic elements but not necessarily all of them. We will talk about two (2) elements, usually both are in every crime.



Identify the two general requirements for criminal liability.

MCCH - Chs. 2.1 to 2.8


1. Act - Actus Reus. To be convicted D must have committed a criminal act. We do not punish thoughts. Usually need an affirmative act by the D. Act may be an omission, that is, a duty to act by law and don't. Examples: Failure to pay taxes, render medical assistance to child.


a. Examples - If affirmative act is required for crime then some conscious and volitional movement is required (i.e. pull trigger - stab victim) Negligent act - had duty to act and did not act.


b. Examples:


Question A1 - Has Defendant committed a third degree assault - no conscious or volitional movement. No, no voluntary movement.


Question A2 - Can you change with property damage 2nd degree. Not knowingly - not conscious and volitional movement.


Question A3 - Turn to your index. What crime has been committed - none. No duty to assist. Therefore, not helping is no "act."


Question A4 - We do not punish criminal thoughts. No duty.



Identify and describe the four culpable mental states. MCCH - Ch. 2.3


Mens Rea. Criminal state of mind - i.e., culpable mental state.


a. What was D thinking at time? State of mind might vary with each element.

b. Not motive - Motive is evidence but not essential - i.e. hate, jealousy, revenge.

c. What is the mental state the particular crime requires?


Purposely - it is his conscious object or desire to engage in the conduct or cause the result

Knowingly - aware that conduct is practically certain to cause a certain result

Recklessly - know of risk of his act and consciously disregarded

Criminal Negligence - Should have known of risk of his acts and disregarded it


d. Note - A few crimes do not require criminal mind. Called strict liability crimes. Just the fact the act occurs is enough.


e. Question B1 - Wouldn't D have done something other than shove victim if he purposely wanted to cause harm. Not purpose - not knowingly causing "great injury."


f. Question B2 - What do you think? Did he know or should he have known of risk. Yes. Reckless.


g. Question B3 - Should D have been aware of the risk and did he disregard it? Yes negligent.


h. Question B4 - Strict Liability. Fact the act occurred is enough.


II. Criminal's defenses based on lack of Mens Rea or Actus Reus.


A. Question C1 - What is Defendant saying - that the mens rea (criminal state of mind) element is not provable. Is it? Guilty?


Not guilty - mistake of fact defense.


a. If culpable mental state is required for there to be a crime then there is a mistake defense if:


1. Purposely and knowingly required - honest mistake.

2. Criminal negligence required - honest and reasonable mistake needed.



Define "entrapment" and give examples of how or when it can occur.

MCCH - Ch. 2.13


B. Entrapment Defense.


1. Requires:

a. Solicitation of or encouragement of criminal conduct to Defendant by police officer and;

b. The Defendant was not already predisposed to commit the crime.


2. D1. Repeated requests//Appeals to sympathy - does it look like Defendant was predisposed (wanted to anyway) to commit - No - probably a defense.


D1a. Predisposed - Agents just gave her an opportunity to commit.

D2b. Can't deny both claim entrapment and commission of crime.


C. Duress.

A defense if D was coerced by use of or threatened, imminent use of unlawful physical force upon him or upon a third person which force or threatened force a person of reasonable firmness would be unable to resist.


1. Age, health, strength taken into account.

2. Question 1 - Yes - 1a - No. Cannot use as a defense to Murder - might mitigate degree as to robbery. May be a defense unless D placed himself recklessly in a situation to be subjected to force. Example: Going to mug someone and his co-defendant said - "Hit victim with this tire iron or I'll hit you." No defense.



Identify the conditions for "Responsibility for the conduct of another." MCCH - Ch. 2.8


Aider and Abettor - Criminal liability for conduct of another.

1. Need purpose to promote offense and.....

a. Aids or;

b. Agrees to aid or;

c. Attempts to aid;

2. Not liable if....

a. Person is victim of offense.

b. Defendant abandons purpose and makes a proper effort to prevent crime.



Identify how being in an intoxicated or drugged condition can affect ones criminal liability. MCCH - Ch. 2.15

Intoxicated//drugged condition.


Example: D goes to bar and stays several hours; he becomes severely intoxicated. While walking home victim accidentally bumps into D. D hits victim, victim falls down. D takes victim's wallet and walks away:

a. How many would convict D for stealing of the wallet (remember, I told you he was drunk). (Conviction).

b. How about convicting D for assault? (Conviction).

c. What if D had ordered non-alcoholic drinks only. The bartender spikes it with a substantial amount of an intoxicating substance (a defense)


Only a defense if:

a. condition is involuntary


Recent legislation allows evidence that a person was in a voluntarily intoxicated or drugged condition to be admissible when otherwise relevant on issues of conduct. Not admissible for the purpose of negating a mental state which is an element of the offense. Recent example: Drive-by in Westport.


b. and deprived D of capacity to know or appreciate nature, quality or wrongfulness of conduct.


Current argument is whether jury gets special instructions.


Mental Disease or Defect.


Does D have a defense? D suffers from severe mental illness. Angered because he incorrectly thinks victim slandered D to his friends, D buys a gun and kills victim. A defense psychiatrist testified at the murder trial that D knew killing victim was wrong and could have resisted but was compelled by his illness to take victim's life. Does D have a defense based on not guilty by reasons of mental disease or defect.


ANSWER: Defense only if at the time of the offense:

a. D did not know or appreciate the nature, quality or wrongfulness of his conduct or;

b. D was incapable of conforming his conduct to requirements of the law.


In example, D knew his conduct was wrong and could control - just did not want to. Guilty - could argue under (b) that he could not control.


OBJECTIVE #6 - State the minimum age requirements for criminal liability.


A child between the ages of 12-17 may be certified for any felony. A child of any age may be certified, and shall have a certification hearing if he/she is alleged to have committed first degree murder, second degree murder, first degree assault, first degree robbery, forcible rape, forcible sodomy, distribution of controlled substances or if the child has committed two or more prior unrelated offenses that would be felonies if committed by an adult. Once a child is certified, the juvenile court shall no longer have jurisdiction over later offenses unless the child is found not guilty by a court of general jurisdiction. (See 211.071 of the Revised Statutes of Missouri)






Revised 4/01