Most Important Criminal Law Cases to Know

The specific opinions vary by casebook. Dressler, Kadish, and Bonnie assign overlapping but different cases for the same doctrines, and your professor may drop half of them. What does not vary is the doctrine: every Criminal Law exam tests voluntary act, mens rea, causation, homicide grading, attempt, complicity, conspiracy, and justification/excuse defenses. The cases below are the ones most likely to be the vehicle for those rules, and each is worth knowing as a one-line holding plus one fact that triggers it.

Two structural rules frame everything. In re Winship, 397 U.S. 358 (1970), requires the prosecution to prove every element beyond a reasonable doubt. Patterson v. New York, 432 U.S. 197 (1977), holds that a state may nonetheless place the burden of persuasion for an affirmative defense on the defendant—as long as it has not, per Mullaney v. Wilbur, 421 U.S. 684 (1975), redefined an element as a defense. Sandstrom v. Montana, 442 U.S. 510 (1979), invalidates jury instructions that presume intent. Burden-shifting issues hide in fact patterns about extreme emotional disturbance and self-defense.

The voluntary act line is short and heavily tested. Martin v. State (Ala. Ct. App. 1944) holds that police cannot carry a drunk man into a public place and then charge him with appearing drunk in public—the actus reus must be voluntary. People v. Decina (N.Y. 1956) is the counterpoint: an epileptic who drives knowing he may seize is liable because the voluntary act occurred earlier, when he got behind the wheel. Robinson v. California, 370 U.S. 660 (1962), holds that punishing the status of narcotics addiction violates the Eighth Amendment; Powell v. Texas, 392 U.S. 514 (1968), refuses to extend Robinson to public drunkenness because conduct, not status, was punished.

For omissions, People v. Beardsley (Mich. 1907) states the baseline no-duty rule, and Jones v. United States (D.C. Cir. 1962) catalogues the four duty sources: statute, status relationship, contract, and voluntary assumption of care that seclues the victim from other aid. Memorize the four; they are exam checkboxes.

Legality and notice cases limit what can be a crime at all. Keeler v. Superior Court (Cal. 1970) held that a viable fetus was not a 'human being' under the murder statute—courts cannot enlarge crimes retroactively. McBoyle v. United States, 283 U.S. 25 (1931), applies lenity and fair-notice reasoning to 'motor vehicle.' Papachristou v. City of Jacksonville, 405 U.S. 156 (1972), and City of Chicago v. Morales, 527 U.S. 41 (1999), void vagrancy and gang-loitering ordinances for vagueness and unfettered police discretion.

Morissette v. United States, 342 U.S. 246 (1952), is the anchor: silence on intent in a statute codifying a common-law crime does not eliminate the mens rea element. Staples v. United States, 511 U.S. 600 (1994), refuses to treat gun possession as a public-welfare offense and requires knowledge of the weapon's automatic-firing characteristics; contrast United States v. Balint (1922) and United States v. Dotterweich (1943) for genuine strict-liability regulatory crimes. Lambert v. California, 355 U.S. 225 (1957), is the rare due process limit on strict liability for a wholly passive omission.

For statutory reading, know the group of Supreme Court cases holding that a mens rea term travels down the sentence: United States v. X-Citement Video (1994) (knowledge of the performer's minority), Flores-Figueroa v. United States (2009) ('knowingly' reaches 'of another person'), Elonis v. United States (2015) (threat convictions require more than negligence), and Rehaif v. United States (2019) (defendant must know his prohibited status). Regina v. Cunningham (1957) supplies the English definition of 'malice' as intent or recklessness—the gas-meter case.

Mistake cases split by system. People v. Navarro (Cal. App. Dep't Super. Ct. 1979) applies the common-law rule that any honest mistake negating specific intent exonerates. Regina v. Prince (1875) illustrates the moral-wrong doctrine for strict-liability elements. Cheek v. United States, 498 U.S. 192 (1991), is the mistake-of-law exception: 'willfully' in the tax code means the defendant knew of the legal duty, though a belief that the tax laws are unconstitutional does not count. Compare all of this to MPC §§ 2.02, 2.04.

Homicide is usually half the final. On premeditation, Commonwealth v. Carroll (Pa. 1963) holds no time is too short to premeditate; State v. Guthrie (W. Va. 1995) demands some period of reflection separate from the intent to kill. Say which side of that split your jurisdiction takes.

On provocation, Girouard v. State (Md. 1991) holds words alone are never adequate provocation; Maher v. People (Mich. 1862) sends reasonableness to the jury rather than confining it to fixed categories. People v. Casassa (N.Y. 1980) applies the MPC's extreme emotional disturbance defense (§ 210.3(1)(b)) with its subjective-situation, objective-reasonableness hybrid. Commonwealth v. Malone (Pa. 1946), the Russian roulette case, defines depraved-heart malice; People v. Knoller (Cal. 2007) requires conscious disregard of a danger to life for implied malice. For involuntary manslaughter, Commonwealth v. Welansky (Mass. 1944) (Cocoanut Grove fire) sets wanton and reckless conduct, and State v. Williams (Wash. Ct. App. 1971) upholds a conviction on ordinary negligence.

Felony murder has four moving parts, each with a signature case: People v. Stamp (Cal. Ct. App. 1969) (strict causal liability—take the victim as you find him), People v. Phillips (Cal. 1966) (inherently dangerous felony, viewed in the abstract), People v. Ireland (Cal. 1969) (merger: assaultive felonies integral to the homicide cannot bootstrap), and State v. Canola (N.J. 1977) (agency versus proximate-cause theory when a co-felon or bystander is killed). Enmund v. Florida, 458 U.S. 782 (1982), and Tison v. Arizona, 481 U.S. 137 (1987), cap the death penalty at major participation plus reckless indifference.

Causation: People v. Acosta (Cal. Ct. App. 1991) (foreseeability limits proximate cause—the helicopter crash), Commonwealth v. Root (Pa. 1961) (drag racing; the victim's reckless choice breaks the chain in criminal law even where tort law would not), Velazquez v. State (Fla. Dist. Ct. App. 1990) (same posture, but-for analysis), and Stephenson v. State (Ind. 1932) (victim's suicide not a superseding cause where the defendant's conduct caused the mental state). Learn the intervening-cause vocabulary: dependent/responsive versus independent/coincidental.

Attempt: People v. Rizzo (N.Y. 1927) states the dangerous-proximity test; United States v. Jackson (2d Cir. 1977) applies the MPC § 5.01 substantial-step-strongly-corroborative test. People v. Dlugash (N.Y. 1977) and People v. Thousand (Mich. 2001) reject legal impossibility as a defense. Smallwood v. State (Md. 1996) shows that recklessness as to death will not support attempted murder—specific intent to kill is required.

Complicity and conspiracy: State v. Gladstone (Wash. 1970) requires a nexus between the aider and the principal, not mere knowledge. Rosemond v. United States (2014) requires advance knowledge of the gun for aiding and abetting a § 924(c) offense. Pinkerton v. United States, 328 U.S. 640 (1946), imposes liability for co-conspirators' foreseeable crimes in furtherance of the conspiracy—compare MPC § 2.06, which rejects Pinkerton. People v. Lauria (Cal. Ct. App. 1967) asks when a supplier's knowledge becomes intent. Kotteakos v. United States, 328 U.S. 750 (1946), and Krulewitch v. United States, 336 U.S. 440 (1949), govern single-versus-multiple conspiracies and the limits on the coconspirator hearsay exception.

Self-defense: People v. Goetz (N.Y. 1986) is the central case—New York's 'reasonably believes' standard is objective, though the jury may consider the defendant's circumstances and relevant prior experience. United States v. Peterson (D.C. Cir. 1973) covers initial aggressors and retreat. State v. Kelly (N.J. 1984) admits battered woman syndrome expert testimony on the reasonableness of the defendant's belief; State v. Norman (N.C. 1989) denies the defense where the batterer was asleep because the threat was not imminent. Norman is the best vehicle for arguing imminence versus necessity.

Necessity and duress: Regina v. Dudley & Stephens (1884) refuses necessity as a defense to murder (the lifeboat case). United States v. Schoon (9th Cir. 1991) forecloses necessity for indirect civil disobedience. State v. Toscano (N.J. 1977) and United States v. Contento-Pachon (9th Cir. 1984) frame duress: a threat of death or serious bodily harm, immediate, with no reasonable escape—and traditionally no duress defense to murder. Compare MPC §§ 3.02 and 2.09, which are broader.

Insanity and intoxication: M'Naghten's Case (1843) supplies the cognitive test (nature and quality of the act, or that it was wrong); MPC § 4.01 adds volitional incapacity; United States v. Brawner (D.C. Cir. 1972) adopted the ALI test and buried Durham's product test. Clark v. Arizona (2006) and Kahler v. Kansas (2020) hold that the Constitution does not require any particular insanity formulation. Montana v. Egelhoff (1996) permits a state to bar voluntary-intoxication evidence on mens rea. Jacobson v. United States, 503 U.S. 540 (1992), is the entrapment case: the government must prove predisposition existed before it approached the defendant.

On an exam, do not brief the case in your answer. Use the name as a two-word signal, then apply the rule: 'Under Guthrie, premeditation requires an appreciable interval of reflection; here Dana loaded the gun twenty minutes before returning, which supports first degree.' Professors reward rule application and split-recognition, not recitation. Where jurisdictions split—Carroll/Guthrie, agency/proximate-cause felony murder, common-law/MPC attempt—argue both and say which produces the better result.

In a paper or memo, cite in Bluebook Rule 10 form. Federal Supreme Court cases take U.S. alone: Morissette v. United States, 342 U.S. 246, 250 (1952). State cases take the regional reporter with the deciding court and year in the parenthetical, omitting the state name only when the reporter already shows it. Add 'Ct. App.' or the equivalent when the decision is not from the highest court. Check every citation in Westlaw or Lexis before you file or submit it; older casebook excerpts sometimes omit subsequent history, and several of these cases have been superseded by statute in their own jurisdictions.