Keeler v. Superior Court is one of those cases that looks like it's about a horrifying set of facts and turns out to be about something much more abstract — and much more important for your exam. A man deliberately stomped on his pregnant ex-wife's abdomen to kill the fetus she was carrying, the fetus died, and the California Supreme Court said: that's not murder. Not because it wasn't monstrous, but because the murder statute said "human being," and in 1970 California a fetus wasn't one under that word. This is the case your professor uses to teach the principle of legality — that courts don't get to invent crimes, even for terrible conduct — and the due-process rule against unforeseeable, retroactive expansion of criminal liability. Get the doctrine right and the awful facts become a footnote.

What did Keeler v. Superior Court hold?

In Keeler v. Superior Court (1970), the California Supreme Court held that an unborn but viable fetus is not a "human being" within the meaning of California's murder statute, and therefore the defendant could not be prosecuted for murder for causing the fetus's death. The court reached this result by interpreting "human being" according to its settled common-law meaning at the time the legislature enacted the statute in 1850 — a meaning that required the victim to have been born alive. The court further held that judicially redefining "human being" to include a fetus would both usurp the legislative function and, applied to Keeler, violate the Due Process Clause by punishing conduct he had no fair warning was criminal.

Case Summary

Keeler v. Superior Court, 2 Cal. 3d 619, 470 P.2d 617 (1970), was decided by the Supreme Court of California. Robert Keeler sought a writ of prohibition to bar the Superior Court from trying him for murder after he assaulted his pregnant former wife and killed the viable fetus she was carrying. The core question was purely one of statutory interpretation: does the word "human being" in California Penal Code § 187 include an unborn, viable fetus? The court answered no, granted the writ, and barred the murder prosecution.

Facts

Robert Keeler and Teresa Keeler had divorced. Teresa became pregnant by another man. In February 1969, Keeler intercepted Teresa on a mountain road. When he learned she was pregnant by another man, he became enraged, said in substance "I'm going to stomp it out of you," and shoved his knee into her abdomen, striking her hard. The fetus — which medical testimony established was viable, weighing about five pounds and roughly 35 weeks developed — suffered a fractured skull and was delivered stillborn. The medical evidence indicated the fetus had likely been alive in utero before the assault and could have survived if born. Keeler was charged with murder under Penal Code § 187, which at the time defined murder as "the unlawful killing of a human being, with malice aforethought."

Procedural History

An information charged Keeler with murder. Keeler moved to set aside the information, arguing the fetus was not a "human being" and thus he could not be charged with murder. The trial (Superior) court denied the motion. Keeler then petitioned the California Supreme Court for a writ of prohibition to restrain the Superior Court from proceeding on the murder charge. The California Supreme Court granted the petition.

Issue

Is an unborn but viable fetus a "human being" within the meaning of California's murder statute (Penal Code § 187), such that a defendant who kills the fetus can be prosecuted for murder? And if the statute does not already cover a fetus, may a court judicially expand the definition of "human being" to include a fetus and apply that expansion to this defendant?

Holding & Rule

The California Supreme Court held that a viable fetus is not a "human being" under Penal Code § 187, and that the murder prosecution could not proceed. Two rules come out of this and both belong in your outline:

• Statutory interpretation rule: Where a criminal statute uses a common-law term ("human being") without defining it, courts give the term the meaning it carried at common law at the time the legislature enacted the statute. In 1850, the settled common-law rule was that a person had to be "born alive" to be a human being capable of being the victim of homicide.
• Separation-of-powers / due-process rule: The power to define crimes and fix punishments belongs to the legislature, not the courts. A court may not judicially enlarge a criminal statute to reach new conduct, and it certainly may not do so and apply the enlargement retroactively to a defendant, because that would deprive him of the fair warning required by the Due Process Clause.

Reasoning

The majority worked through two distinct steps, and keeping them separate is the key to understanding the case.

Step one — what did "human being" mean? The court traced the term to its common-law roots. At common law, the settled rule was that homicide required the victim to have been "born alive" — a fetus, however far developed, was not a subject of homicide. California adopted its Penal Code language in 1850 (and re-enacted § 187 in 1872) against that background, and the court presumed the legislature intended the common-law meaning. Because the legislature had never redefined "human being" to include a fetus, the statute did not reach Keeler's conduct.

Step two — could the court fix that gap itself? The prosecution urged the court to "update" the definition to reflect modern medicine, under which a viable fetus can survive outside the womb. The court refused, on two grounds. First, separation of powers: defining crimes is a legislative act, and enlarging § 187 to cover a fetus would be an act of judicial legislation the court had no authority to perform. Second, and independently dispositive, due process: even if the court could expand the statute prospectively, it could not apply an unforeseeable judicial enlargement to Keeler. Relying on the U.S. Supreme Court's decision in Bouie v. City of Columbia, the court explained that an unforeseeable judicial construction of a criminal statute that operates to the defendant's detriment is the equivalent of an ex post facto law and violates due process. Keeler could not have known that stomping the fetus was "murder" when the statute said "human being" and the law had always meant born-alive.

The dissent (Justice Burke). The dissent argued that a viable fetus is, in reality and in common understanding, a human being, and that the majority's rigid reliance on an ancient "born alive" rule — a rule rooted in the primitive medical knowledge of centuries past — produced an unjust result and abdicated the court's proper interpretive role. The dissent would have read "human being" in light of modern medical viability. This is worth knowing because it frames the exact policy fight your professor will run in class: does the born-alive rule reflect a considered legislative choice, or just an outdated evidentiary convenience the court should have modernized?

Why Keeler Matters

Keeler sits at the front of most Criminal Law courses because it is the cleanest possible vehicle for the principle of legality — nullum crimen sine lege, no crime without a pre-existing law. It bundles together three doctrines that show up all semester: (1) the requirement that criminal statutes give fair warning of what is prohibited; (2) the rule of lenity, which resolves genuine ambiguity in penal statutes in favor of the defendant; and (3) the separation-of-powers limit that keeps courts from inventing crimes. It also demonstrates a legislature-court dialogue in action: after Keeler, the California Legislature amended § 187 to define murder as the unlawful killing of "a human being, or a fetus," with malice aforethought. That amendment is the punchline — the court told the legislature "if you want fetal killing to be murder, say so," and the legislature did. That is exactly how the system is supposed to work, and it's why Keeler pairs naturally with cases on vagueness and construction of criminal statutes.

Cold-Call Prep

Here are the questions your professor will actually ask on Keeler and how to answer each without getting spun.

"Why isn't this murder? He obviously killed the fetus on purpose." — Because the statute defined murder as killing a "human being," and at the time it was enacted the common law meant a born-alive person by that term. Intent and moral blameworthiness don't matter to this question; the statute simply didn't cover the conduct. Lead with the statutory language, not the facts.

"Why does the court care what 'human being' meant in 1850?" — Because the legislature enacted the statute in 1850 (re-enacted 1872) using an undefined common-law term, and the presumption is that the legislature adopted the term's settled common-law meaning. The court is interpreting the legislature's intent, not deciding for itself what a human being is.

"The court admits a viable fetus can survive outside the womb. Why not just update the definition?" — Two reasons. Separation of powers: defining crimes is the legislature's job. And due process: even a good-faith judicial expansion can't be applied to Keeler, because he had no fair warning — that's the Bouie point. Naming Bouie v. City of Columbia and the "unforeseeable judicial enlargement = ex post facto" idea is a green-flag answer.

"Isn't this just the court letting a killer walk on a technicality?" — Don't take the bait as if the answer is obviously yes. The "technicality" is the principle of legality — the same rule that protects everyone from being convicted of conduct that wasn't a crime when they did it. The remedy isn't for courts to bend; it's for the legislature to amend the statute, which is exactly what California did.

"What did the dissent say, and were they right?" — Justice Burke argued that a viable fetus is a human being in fact and that the majority hid behind an obsolete rule. Answer the normative question by separating it from the doctrinal one: the dissent may have the better policy argument, but the majority has the better argument about who gets to make that policy choice. That distinction is what the professor is really testing.

"How did the story end?" — The legislature amended § 187 to add "or a fetus." Institutional dialogue: court identifies the gap, legislature closes it prospectively.

On the Exam

Keeler is rarely tested as "brief this case." It shows up as a doctrine you deploy on a statutory-interpretation issue. The classic fact pattern: a defendant does something clearly bad, and a prosecutor tries to squeeze it into an existing criminal statute whose text arguably doesn't cover it. Your move is a legality analysis: Does the statute's language, read at its enactment and construed strictly, actually reach this conduct? If it's ambiguous, the rule of lenity tilts toward the defendant. And can a court expand the statute and apply the expansion to this defendant, or does that offend the fair-warning requirement of due process (the Bouie principle)?

The trap: students let the awful facts drive the analysis and conclude "of course he's guilty, look what he did." That's the wrong instinct and it's exactly what Keeler is designed to break. The exam is testing whether you can hold moral blameworthiness apart from statutory coverage. State the split explicitly: "Although the conduct is plainly culpable, the statute as written does not reach it, and under Keeler a court may not judicially expand it to Keeler's detriment; the proper fix is legislative." That sentence earns points because it shows you understand the two-step structure — coverage first, then the limits on judicial expansion.

Related Cases

• Bouie v. City of Columbia (1964) — the U.S. Supreme Court source of the due-process rule against unforeseeable, retroactive judicial expansion of criminal statutes; Keeler leans on it directly.
• Rogers v. Tennessee (2001) — later Supreme Court case limiting Bouie, upholding the abolition of the common-law "year-and-a-day" rule; often taught alongside Keeler to show the outer bound of the fair-warning principle.
• Commonwealth v. Mochan — the flip side: a court arguably did create a crime by common law, illustrating the danger Keeler guards against.
• McBoyle v. United States (1931) — Holmes's opinion on fair warning and strict construction of penal statutes (does "vehicle" include an airplane?); a companion legality case.

Frequently Asked Questions

See the FAQ section below for the questions students ask most about Keeler.