No Crime Without a Statute: The Principle of Legality in California Law

Murder is Legal Unless There is a Law because in California there are no common law crimes.

This is not true in every state and in many areas of law such as contracts or accident cases, British Common law (or French law in Louisiana) predate the existence of the United States but their rules can still govern conduct in this country. The influence of British common law starts with the Colonies.

How British Common Law Became Part of the Law in the United States

The United States legal system is fundamentally a common law system, derived from British (English) common law. This means that much of American law—especially in areas like contracts, torts, property, and judicial precedent—traces its roots to the judge-made law developed in England over centuries. However, it's not "British law" in the sense of being directly imposed or current English law; it's the historical English common law as received and adapted in America.

Historical Reception in the Colonies

British colonists brought English common law with them to North America. Colonial charters and practices often explicitly or implicitly incorporated it.

Early settlers viewed English common law as their "birthright" as English subjects.
Colonies like Virginia (in its 1606 charter) and Massachusetts applied English law where suitable to local conditions.
By the time of the American Revolution (1776), English common law (up to a certain date, often around July 4, 1776, or the colony's founding) was the foundation of colonial jurisprudence.

After independence, the new states did not start from scratch. They needed a predictable body of law for governance, commerce, and disputes.

Reception Statutes and Judicial Adoption

All U.S. states except Louisiana (which follows a civil law tradition from French and Spanish roots) adopted English common law through:

Reception statutes: Laws explicitly stating that English common law (and sometimes certain statutes) in effect as of a cutoff date (often 1776 or 1607, referencing the first permanent English settlement in Jamestown) would serve as the baseline law, unless "repugnant" to the state's constitution, laws, or local conditions.
- Example: Many states' statutes declare something like: "The common law of England, so far as it is not inconsistent with the Constitution and laws of the United States or of this state, shall be the rule of decision."
Judicial decisions or constitutional provisions: In some states, courts or constitutions directly recognized common law without a specific statute.

This "reception" made pre-Revolution English common law the default rule where no local statute existed. Over time:

American courts modified it to fit U.S. conditions (e.g., democratic values, federalism).
Legislatures codified or overridden parts with statutes.
Post-1776 English developments are not binding but can be persuasive.

At the federal level, there is no general reception statute, but federal courts inherited the common law judicial power (precedent-setting via stare decisis). Limited "federal common law" exists in areas like interstate disputes or admiralty.

Key Areas Where British Common Law Persists

Private law: Contracts (e.g., offer, acceptance, consideration), torts (negligence, trespass), property (estates in land, rules against perpetuities).
Procedural principles: Adversarial system, jury trials, presumption of innocence.
Precedent (stare decisis): Courts follow prior decisions, building law case-by-case—like English courts.
Even modern U.S. Supreme Court cases sometimes cite ancient English precedents for historical context (e.g., in Dobbs v. Jackson Women's Health Organization (2022), referencing 13th-century English law on abortion).

Important Limitations and Divergences (and showing off our Latin :] )

Criminal law: Federal crimes are entirely statutory (no federal common law crimes since United States v. Hudson (1812)). The same is true in California.

In criminal law, one of the most fundamental protections for individuals is the idea that no act is a crime unless a law explicitly says so. This principle, rooted in the Latin maxim nullum crimen sine lege ("no crime without law") and nulla poena sine lege ("no punishment without law"), ensures that people can only be prosecuted and punished for conduct clearly prohibited by written law in advance. Retroactive laws or vague prohibitions are forbidden, protecting against arbitrary government power.

California takes this principle further than many states by completely abolishing common law crimes. In most U.S. jurisdictions, even today, some offenses can be based on "common law"—judge-made rules inherited from English tradition, without a specific statute. But in California, that's not the case.

The Key Law: California Penal Code Section 6

The foundation is found right at the beginning of the California Penal Code, in Section 6:

"No act or omission... is criminal or punishable, except as prescribed or authorized by this Code, or by some of the statutes which it specifies as continuing in force... or by some ordinance, municipal, county, or township regulation..."

Enacted in 1872 when California adopted its comprehensive Penal Code, this section explicitly states that only statutory law (the Penal Code itself, certain continuing statutes, or local ordinances) can define crimes. Acts committed before the Code took effect could still be prosecuted under old rules, but everything after noon on January 1, 1873, falls under this rule.

In plain terms: If there's no statute prohibiting it, it's not a crime in California. Prosecutors cannot fall back on vague "common law" offenses like they might in some other states. Every criminal charge must point to a specific code section defining the prohibited conduct and its punishment.

What This Means in Practice

Every crime has a code section: Murder (Penal Code §§ 187–199), theft (§§ 484–502), drug offenses (mostly in the Health & Safety Code), DUI (Vehicle Code § 23152), and so on. Prosecutors cite the exact section in charging documents.
No "catch-all" common law fallback: If behavior is harmful but not covered by statute, the legislature must pass a new law. Courts cannot create new crimes.
Local ordinances fill minor gaps: Things like noise violations or petty local rules can be crimes if authorized by state law, but still must be written.
The more recent law is presumed to have considered only pre-existing published laws (not common law)
The more specific law is presumed to have been written with the earlier or related statute in mind.

Statutory interpretation is always a key factor in appellate law and civil litigation. Increasingly statutory interpretation and motions such as Williamson motions or non-statutory motions to dismiss are important in criminal cases. The fact that the California criminal universe is limited to California statute simplifies matters but only a bit. You always have the federal constitutional rules and rights to interplay with state law. Is a statute unconstitutionally vague? If so, federal constitutional law will be in play.

If you have a complex criminal case a State of California certified criminal defense lawyer will be your best legal choice. Daniel Horowitz is a State Bar Board of Legal Specialization certified criminal law specialist. Call Daniel for an initial consultation at (925) 283-1863