Criminal Law and Procedure
Criminal Law and Procedure
Criminal questions combine substantive mens rea and homicide doctrine with Fourth, Fifth, and Sixth Amendment procedure. State the mental state and the constitutional standard explicitly.
Substantive law
- Model Penal Code culpability: purposely, knowingly, recklessly, negligently.
- Murder requires malice: intent to kill, intent to cause serious bodily harm, depraved-heart recklessness, or felony murder. Voluntary manslaughter requires adequate provocation and heat of passion; involuntary manslaughter is reckless or negligent.
- Attempt requires intent plus a substantial step. Conspiracy requires agreement and, under the MPC, a substantial step; common law requires an overt act in many jurisdictions.
- Accomplice liability requires intent to assist. Withdrawal must be timely and communicated.
Defenses
- Self-defense requires reasonable belief in imminent unlawful force and proportional force. The MPC uses a subjective standard; common law uses a reasonable-person standard.
- Duress is not a defense to homicide. Insanity tests include M'Naghten and the MPC volitional prong.
Procedure
- Fourth Amendment: warrants require probable cause and particularity. Exceptions include search incident to arrest, automobile, consent, plain view, exigency, and Terry stops with reasonable suspicion.
- Fifth Amendment: Miranda applies to custodial interrogation; invocation must be unambiguous; waiver must be knowing and voluntary.
- Sixth Amendment: counsel attaches at critical stages after formal proceedings; testimonial hearsay requires confrontation unless the declarant is unavailable and was cross-examined.
Worked example
An officer stops a car for speeding and smells burnt marijuana. The odor supplies probable cause to search the passenger compartment and trunk under the automobile exception. Marijuana found in the trunk is admissible; no warrant is required.
Traps
- Treating a Terry stop as custody for Miranda purposes.
- Applying felony murder when the underlying felony merges with the homicide.
- Confusing the objective common law self-defense standard with the MPC subjective standard.