Mistake of Law in Minnesota: When Ignorance Is (and Isn't) a Defense

The General Rule: Ignorance of the Law Is No Excuse

Criminal law generally presumes that people are responsible for knowing what the law prohibits. You usually cannot defend a charge by saying you didn't realize your conduct was illegal. If the State proves you intended to do the act and the act is a crime, your unawareness that it was against the law ordinarily does not excuse it.

What this means for you: "I didn't know that was illegal" is, by itself, rarely a winning defense. The law expects citizens to know the rules, even unfamiliar or technical ones.

The Narrow Exception: Reliance on Official Statements

One recognized exception is reasonable reliance on an official statement of the law — sometimes called government estoppel. If you acted in good-faith reliance on an official interpretation of the law (for example, from a public official or agency charged with administering it) that was later determined to be incorrect, that reliance may, in narrow circumstances, provide a defense. This is a limited and fact-specific doctrine.

What this means for you: Relying on a friend's opinion, a website, or your own reading of a statute is not the same as relying on an authoritative official statement. The exception is narrow and depends heavily on who said what, in what capacity, and whether the reliance was reasonable.

When the Crime Itself Requires Knowledge of the Law

A few offenses are written so that knowledge of a legal requirement — or willful violation of a known legal duty — is actually part of what the State must prove. For those specific crimes, a genuine misunderstanding can negate that required element. But this is a feature of the particular statute, not a general license to claim ignorance.

Mistake of Law vs. Mistake of Fact

This distinction is critical. A mistake of fact — a misunderstanding about a factual circumstance — can negate criminal intent and is a recognized defense for intent-based crimes. A mistake of law — misunderstanding what the law prohibits — generally is not. Cases sometimes turn on how a particular misunderstanding is characterized.

Good Faith and Related Doctrines

Mistake of law overlaps with other concepts like good faith, advice of counsel, and government estoppel. In certain offenses — particularly some regulatory or specific-intent crimes — a good-faith belief, including one based on advice of counsel, can bear on whether the required intent existed. Whether any of these apply depends entirely on the charge.