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Criminal Law
South Texas College of Law Houston
Williams, Kenneth A.

Criminal Law Outline

Professor Kenneth Williams

Spring 2013

I. Elements of a crime:

a. Actus Reus – voluntary act

b. Mens Rea – mental state

c. Attendant circumstances

d. Harm

Actus Reus

Statute or code will determine what is the act – Ex: public intoxication. The Actus Reus for D is to be drunk, appear in public, and be boisterous with loud and profane discourse (all voluntary actions).

a. Two Elements:

I. Act or Legal Omission

1. Act = conduct (not thoughts)

2. Omission = duty to act in limited circumstances:

a. Special relationship (parent / child)

b. Contract (babysitter)

c. Statutory duty (income tax)

d. Create the risk

e. Voluntarily assume the care

II. Voluntary

1. Movement controlled by the mind and not just the brain. Ex: D gets in car and drives to corner store, but hits P à sudden onset of seizure = brain (involuntary); previous history of seizure = mind (voluntary).

Ex: Marijuana legal in Canada and Dom. Republic. D flies non-stop from Canada to Dominican Republic. Plane takes an emergency landing in New York where marijuana is illegal if “one knowingly possesses it.” D did not have the actus reus. D did not possess the marijuana in New York voluntarily; only due to emergency landing. It was beyond his control (i.e. a seizure)

Status Crimes

I. Cannot be convicted based on a status (who you are)

II. Conviction must contain an act, and status is not an act

a. Addicted = status; using = conduct

Mens Rea

I. Model Penal Code

a. Purpose

i. D’s conscious object to engage in conduct of that nature or to cause such a result (subjective)

ii. Attendant circumstances – D is aware of existence of such circumstances or he believes or hopes that they exist

b. Knowledge

i. D is aware (actual knowledge) + practically certain (correctly believes) that his conduct will cause a certain result. (Subjective)

ii. Willful blindness – D is aware of high probability of existence of fact; and

1. Takes deliberate action to avoid confirming the fact; or

2. Purposely fails to investigate to avoid confirming the fact

iii. Attendant circumstances – D must be aware that his conduct is of that nature

c. Reckless

i. D consciously disregards (subjective) a substantial and unjustifiable risk that the material element exists or will result from his conduct

ii. Gross deviation from standard of conduct.

d. Negligence

i. D should be aware (objective) of a substantial and unjustifiable risk that the material element

exists or will result from his conduct

II. Common Law

a. Specific Intent

i. Intent will be addressed in the statute

b. General Intent

i. Statute does not say the mens rea but it must be shown at the default of recklessness

c. Trans

c. Strict liability – no mens rea therefore no mistake permitted.

II. Mistake of Law – General rule is no excuse, but it may be used as a defense. Marrero – only a defense if a public servant who is charged with interpreting that specific category of law tells you something wrong and you rely on it.

a. Bryant exception – law is well known that one must register if they are a sex offender so when D argued mistake of law for not registering, it was not a defense.

III. MPC – Mistake can negate purpose, knowledge, recklessness, but not negligence because of reasonable person standard.


Negates specific intent mens rea ONLY

Prof. Williams said it’s not really a defense (cannot prove all elements of the crime)

Two Types: (Both can negate mens rea)

Voluntary – knowingly ingests a substance (medicine or alcohol)

Ex: knowingly takes medicine that causes drowsiness and then drives a car

Involuntary – allowing others to ingest your body with a substance without free will through trickery or force

Ex: date rape drug

Defense rarely succeeds – If it does, D must have been heavily intoxicated to the point where D cannot form mens rea.