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Criminal Law
University of California, Hastings School of Law
Weithorn, Lois A.

1L Criminal Law

Professor Weithorn

Fall 2015-UC Hastings

Basic Definition: Act + Mental State = Crime – Defenses

Exam Tips

· If she talks about jury instructions, you need to apply general principles of doctrine, with cases and statutes.

· If she talks about policy (She will!)

· 1) Figure out elements of the crime. Start with statute. Use tools of statutory analysis (plain language, legislative intent.)

· Premeditated or crime of passion? Must do an outline of what steps need to be figured out.

· You want to raise all possible arguments.

· Slam dunk issues are clear, some issues that are going to be heavily contested by both sides. Apportion your time in a way that practitioners would.

· If you are not told what jurisdiction, you need to discuss all jurisdiction’s takes (traditional common law, common law today and MPC).

· Elemental analysis, Elements of crime, which leads to mental state which is one of those elements. Attendant circumstances.

· You want to figure out what is being asked of you. You can figure out broad question, but key is to figure out sub questions that might not be fully visible or made clear.

· For Weithorn, being able to identify applicable issue and applicable statutes, in your analysis, is key. If you have ultimate conclusion that is a little different, not going to be a problem. Like math, show your work. Yes you want to state a conclusion, but it is more on how you get there.

· Even if slam dunk issue, explain other side.

· Don’t spend a lot of time on stuff that wouldn’t be issue in the real world! Ask yourself, is the act what is the issue? If not, be short, sweet, and move to the meat of the issue.

Elements of a Crime

· Act/Conduct

o Most crimes in the U.S. consist of four basic elements: (1) a voluntary act (or omission when there is a legal duty to act) that results in some kind of social harm (“actus reus”); (2) a prohibited mental state (“mens rea” or “guilty mind”); (3) a chain of causation that links defendant’s actions with the social harm; and (4) concurrence between the mens rea and actus reus.

o All crimes require actus reus. That is, a criminal act or an unlawful omission of an act, must have occurred. A person cannot be punished for thinking criminal thoughts. The omission of an act can also constitute the basis for criminal liability.

o Conduct-Marriage of actus reus and mens rea.

o (1) Voluntary act (2) that causes (3) social harm.

o Some employ “actus reus” in a narrow sense to refer only to the conduct element of a crime.

o Others give “actus reus a broader scope, referring to all non-mental elements of an offense”

o Often combined with mens rea to prove criminal liability beyond a reasonable doubt. Ex.) A picks up knife, stabs B, killing him. Actus Reus of criminal homicide has occurred.

· Mental State – Mens Reas

o Blameworthiness attached to the intent/thought of the offender.

o Must act on the mental state in order to be a criminal offense. Just thinking about bad things is not a crime.

· Result

o Some crimes require a result in order to be an offense. Ex.) Homicide requires death (death is the result that must occur. If no death, it would fall under attempted homicide).

· Causation

o Usually if you have a result, then you have causation. If you have the causation, usually you have the result.

· Attendant Circumstances

o Certain circumstances that must be satisfied in order for this specific intent crime to be intended.

o So many possibilities: they are laid out in the statute

o Its basically facts that define the situation. Ex.) Statutory Rape. Victim must be under the age of 16. Age must be proven. Ex.) Burglaries. Require inhabited dwelling element. Ex.) Drug cases. Different drug, different punishment.

Actus Reus

Common Law

Model Penal Code

· Must actually commit act. Can’t be just thoughts.

· Must be voluntary.

· No criminal liability for omission unless person who failed to act had a legal duty to act.

· “Status Crimes” are unconstitutional: people should only be criminally punished for their conduct, not simply for being a certain kind of person.

· Robinson v. California (status): CA statute that made being addicted to narcotics a criminal offense. Ruled unconstitutional by 14th Amendment.. Drug addiction is a disease out of person’s control. Addiction lacks the “act” element necessary since it is out of the person’s control. Rule: A statute that imprisons a defendant solely on account of their status of being a drug addict is in violation of the 14th Amendment. You can criminalize act, but not desire.

· Powell v. Texas (not status, but act): Distinguished from Robinson, as Robinson dealt with a defendant who was punished for merely having an addicti

rt or determination of the actor, either conscious or habitual.

· (3) Liability for commission of offense may not be based on omission accompanied by action unless: omission is expressly made sufficient by law defining offense OR duty to perform omitted act otherwise imposed by law.

· (4) Possession is an act if possessor knowingly procured or received thing possessed or was aware of his control thereof for sufficient period to have been able to terminate his possession.



Recklessness: awareness of risk.

Negligence: comparing defendant to ordinary careful person.

Possession: Neither an act or an omission. Pragmatic for facilitating law enforcement??

Possession: MPC 2.01(4) Possession is an act if possessor knowingly procured or received thing possessed or was aware of his control thereof for sufficient period to have been able to terminate his possession.


· Criminal liability can be based upon an omission if D had a legal duty to act and was physically capable of acting. The omission, which replaces the voluntary act, must also cause social harm, and defendant must act with requisite mens rea in order to be convicted of offense. Must also have known of the facts giving rise to the situation.

· Five situations in which individuals have a legal duty to act:

o 1) Special relationship

o 2) Contract

o 3) Statutory Duty to Act

o 4) When defendant creates the risk of harm to the victim

o 5) When defendant voluntarily assumes care of a person in need for help.

· Commonwealth v. Pestinikas (Duty to Act): Couple agrees to take care of old man for money, puts him in shed, and leaves him. He dies of starvation. You can be criminally charged with murder for omission of act to save old man if you have a legal duty to act. Rule: You have a duty to act when you contract to care for someone.