3Criminal Law

General Principles

This week introduces the foundational concepts of criminal law: the sources of criminal law, the distinction between common law and the Model Penal Code (MPC), the elements of a crime (actus reus and mens rea), and the classification of crimes. Students will learn the four MPC mental states and how to apply them to statutory analysis.

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Learning Objectives

Identify the sources of criminal law: common law, MPC, and state/federal statutes
Define actus reus (voluntary act, omission, possession, status) and apply the voluntariness requirement
Define and distinguish the four MPC mental states: purposely, knowingly, recklessly, negligently
Compare MPC mental states with common law mental states (specific intent, general intent, malice, strict liability)
Explain the concurrence requirement: actus reus and mens rea must coincide
Classify crimes as felonies and misdemeanors and understand grading

Key Rules

A crime requires: (1) actus reus (guilty act), (2) mens rea (guilty mind), (3) concurrence of act and intent, and (4) causation (for result crimes).
Actus reus must be a voluntary act. Involuntary acts (reflexes, convulsions, acts during unconsciousness or sleep) are not actus reus. MPC § 2.01.
Omission is actus reus only when D has a legal duty to act. Duties arise from: statute, contract, relationship (parent-child, spouse), voluntary assumption of care, or creation of peril.
MPC § 2.02 Mental States (from most to least culpable): (1) Purposely — conscious object to engage in conduct or cause result; (2) Knowingly — aware that conduct is of a certain nature or practically certain result will occur; (3) Recklessly — conscious disregard of a substantial and unjustifiable risk; (4) Negligently — should be aware of a substantial and unjustifiable risk (objective standard).
Common law intent: Specific intent crimes require a particular mental state beyond the actus reus (e.g., larceny requires intent to permanently deprive). General intent crimes require only intent to do the prohibited act.
Strict liability: No mens rea required. Common for regulatory/public welfare offenses (traffic violations, statutory rape in many jurisdictions, selling alcohol to minors).
Concurrence: The mens rea must actuate (motivate) the actus reus. The intent must exist at the time of the act.

General Principles of Criminal Law

Sources of Criminal Law

Common Law

Historically, crimes were defined by judges through case law. Most states have now codified their criminal law by statute, but common law terminology and concepts persist.

Model Penal Code (MPC)

The American Law Institute published the MPC in 1962 as a model for state legislatures. About two-thirds of states have adopted some MPC provisions. The MPC provides: - A systematic approach to criminal liability - Four defined mental states (replacing common law's confusing array) - Comprehensive defenses framework

Statutes

Criminal law is now primarily statutory. The principle of legality (nullum crimen sine lege) requires that crimes be defined by statute before conduct occurs. Courts cannot create new crimes.

Actus Reus — The Guilty Act

Voluntary Act Requirement

The actus reus must include a voluntary act by the defendant. MPC § 2.01(1).

Voluntary acts: Walking, speaking, driving, pointing a gun, taking property.

Involuntary acts (NOT actus reus): - Reflexes and convulsions - Acts during unconsciousness or sleep (but see habitual sleepwalking) - Conduct during hypnosis - A bodily movement not the product of the actor's effort or determination

Key Point: If D has a seizure while driving and hits a pedestrian, there is no voluntary act. But if D knows about the seizure condition and chooses to drive anyway, the voluntary act is the decision to drive.

Omission as Actus Reus

Generally, there is no duty to act in criminal law — no Good Samaritan obligation. But omission can be actus reus when D has a legal duty to act:

1. Statute — e.g., duty to file tax returns, duty to report child abuse 2. Contract — e.g., lifeguard, nurse, babysitter 3. Relationship — parent to child, spouse to spouse (in some jurisdictions) 4. Voluntary assumption of care — e.g., taking in an elderly person and then failing to provide food 5. Creation of peril — if D creates the danger, D has a duty to rescue

Possession as Actus Reus

Possession can be actus reus if: - D was aware of the possession (actual or constructive) - D had sufficient time to terminate possession

Status Crimes (Unconstitutional)

The government cannot criminalize a status or condition. Robinson v. California (1962): punishing someone for being addicted to narcotics violates the 8th Amendment (cruel and unusual punishment). But the government CAN punish the act of using narcotics.

Mens Rea — The Guilty Mind

MPC Mental States (§ 2.02)

| Level | Definition | Standard | Example | |-------|-----------|----------|---------| | Purposely | Conscious object to engage in conduct or cause result | Subjective | D aims gun at V and pulls trigger, wanting to kill V | | Knowingly | Awareness that conduct is of a certain nature; practical certainty of result | Subjective | D ships a package knowing it contains drugs | | Recklessly | Conscious disregard of a substantial and unjustifiable risk | Subjective (awareness) + Objective (unjustifiable) | D drives 90 mph through a school zone, aware of the risk | | Negligently | Should be aware of a substantial and unjustifiable risk | Objective | D fails to check mirrors before changing lanes, causing accident |

Critical Hierarchy: Purpose > Knowledge > Recklessness > Negligence. If a statute requires "recklessness" and D acted "purposely," the mens rea is satisfied (higher satisfies lower).

Common Law Mental States

| Term | Meaning | MPC Equivalent | |------|---------|---------------| | Specific Intent | D must intend a particular result beyond the act itself | Purposely | | General Intent | D must intend to do the prohibited act | Knowingly or Recklessly | | Malice | Reckless disregard of an obvious risk | Recklessly | | Strict Liability | No mental state required | N/A |

Common Specific Intent Crimes (memory aid: "FIAT BALSA"): - First-degree murder, Inchoate crimes (attempt, solicitation, conspiracy) - Assault (with intent to commit battery), Theft crimes (larceny, robbery, burglary, embezzlement) - Burglary, Attempt, Larceny, Solicitation, Assembly (unlawful)

Concurrence

The mens rea must actuate (cause/motivate) the actus reus. They must exist at the same time.

Example of no concurrence: D decides to kill V on Monday. On Tuesday, D has completely abandoned the plan. On Wednesday, D accidentally hits V with his car (pure negligence). D is not guilty of murder — the intent to kill (Monday) did not coincide with the act (Wednesday).

Classification of Crimes

| Classification | Punishment | Examples | |---------------|-----------|---------| | Felony | > 1 year imprisonment | Murder, rape, robbery, burglary | | Misdemeanor | ≤ 1 year imprisonment | Simple assault, petty theft, DUI (first offense) | | Infractions | Fine only | Traffic violations, jaywalking |

Cases to Know

Robinson v. California (1962) — cannot criminalize a status (drug addiction); 8th Amendment
Martin v. State (1944) — voluntary act requirement: police dragged drunk man onto public highway, no voluntary act
People v. Beardsley (1907) — no legal duty to act for a social guest (mistress who overdosed)
Jones v. United States (1962) — four categories of legal duty to act

California Codes — Official Authority

The statutes SofAI ties to this topic. Use them as your IRAC rule block, then verify the current text on the official leginfo link.

Cal. Penal Code §240 — Assault definedleginfo
Assault is an unlawful attempt, coupled with a present ability, to commit a violent injury on someone.
Cal. Penal Code §242 — Battery definedleginfo
Battery is any willful and unlawful use of force or violence upon another person.
Cal. Penal Code §20 — Union of act and intentleginfo
In every crime there must be a union, or joint operation, of act and intent (or criminal negligence).
Exam hook: Open a Criminal Law essay by confirming concurrence of act and intent under §20 before analyzing specific crimes.

Explore all California Codes

Baby Bar Relevance

The Baby Bar tests Criminal Law as one of its three subjects. Every criminal law question requires identifying actus reus and mens rea. The MPC mental states framework is essential for analyzing statutory crimes. Omission liability and the voluntary act requirement are frequently tested.

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