Apr 15, 2025
Mistake of Law in Criminal Law: Principles, Practice, and Issues
Mistake of law occurs when a person acts in good faith because they were not aware of the legal rule that has been violated, have received incorrect information about the content of the rules, or have interpreted legal rules differently than the courts find correct. The issue of the significance of mistake of law for criminal liability is particularly relevant in the violation of special legislation and the minor offenses chapters of the Penal Code, but occurs less frequently in more serious crimes where the main tenets of the Penal Code are known to all adults and normal individuals.
This article provides an overview of the rules regarding mistake of law in Norwegian criminal law, and addresses key issues related to when and how mistake of law can be invoked as a ground for exemption from or reduction of punishment.
Basics of Mistake of Law
Mistake of Law vs. Conscientious Offender
It is important to distinguish between mistake of law and the so-called "conscientious offender." In a mistake of law, the perpetrator is not aware that the action is punishable or illegal. The conscientious offender, on the other hand, is fully aware of what the law prohibits or mandates but believes they have a religious or moral duty to act against the law.
Examples of conscientious offenders may include the pacifist who encourages draft evasion, the Adventist who does not comply with police orders for street sweeping on Saturdays, or the environmentalist who obstructs development work. These individuals typically act in the conviction that they are following a higher law than the civic one, but since they are aware of what their country's law prohibits or mandates, it does not constitute a mistake of law.
Penal Code § 57 - General Rule on Mistake of Law
The Penal Code § 57 states: “For the person who, at the time of the action, was mistaken regarding its unlawful nature, the sentence may, if the court does not find reason to acquit on this basis, be reduced below the minimum prescribed for the action and to a milder penalty.”
The provision gives the court four alternatives:
Complete acquittal
Reduction of the sentence below the usual minimum or to a milder form of punishment
Consideration of the mistake as a mitigating factor within the usual legal framework
No significance attributed to the mistake
The Penal Code does not stipulate a specific principle for choosing between these alternatives, and the legislative history assumes that it is left to the court's prudent judgment to decide when the penalty should be reduced or entirely dropped.
The Principle of "Excusable Mistake of Law"
In legal practice, it is a firmly established principle that only the excusable mistake of law leads to acquittal. This means only the mistake of law that cannot be attributed to the perpetrator - not even as negligence - acts as an exemption from punishment. A negligent mistake of law can affect sentencing, but not the liability itself.
The principle also applies where the prohibition contains the expression "unlawful" or a similar reservation. What is required is knowledge of the factual circumstances that form the basis of the legal characterization, not knowledge of the meaning of the terms used in the law.
When is a Mistake of Law Excusable?
The general rule is that mistake of law is not accepted. Special circumstances are required for it to be recognized as excusable. This may seem strict, especially in today's society with numerous laws and regulations. However, what is required of citizens are two things:
Knowledge of the general rules of coexistence that apply to all people
Knowledge of special rules for the profession or activity that the individual engages in
The assessment is nonetheless strict. That the general public in similar situations has had the same perception as the accused is not by itself enough for acquittal. It takes particularly compelling reasons for someone engaged in professional activity to be acquitted due to insufficient knowledge of the rules applicable to the activity.
Factors That May Make a Mistake of Law Excusable
When assessing whether a mistake of law is excusable, several factors are considered:
Position of the accused: Stricter requirements are set for the owner or manager of a business than for subordinates. The subordinate must generally be free of responsibility when acting in good faith following the superior's instructions without particular reason for suspicion.
Age, education, and intellectual capacity of the accused: This can be significant, especially regarding general rules of coexistence. For special rules related to a profession, it is more difficult to claim lack of understanding or experience.
New rules: A circumstance that may make the mistake excusable is that the rule is new, especially if the announcement has not been effective as it should have been.
Foreign perpetrators: It may be excusable that a foreign tourist has not familiarized themselves with all details of Norwegian legislation. However, it is expected that a foreign business person familiarizes themselves with the rules for their business in Norway.
Doubtful legal interpretation: When the interpretation of the law has been doubtful, this may be a ground for excuse. If the accused has relied on an interpretation expressed in the law's motives, previous practice, or statements from public authorities, this may be excusable even if the court now adopts a different interpretation.
The decisive factor is not so much an isolated assessment of whether the mistake of law is excusable, as a comprehensive evaluation of the conduct. Only if the mistake of law makes the actual conduct justifiable, will it generally be accepted as exempt from punishment.
Relationship Between § 42 and § 57 - Factual and Legal Mistake
The Boundary Between Factual and Legal Mistake
In some cases, there may be doubt about where the boundary lies between factual mistake (§ 42) and mistake of law (§ 57). In prohibitions where only negligence is required for conviction, the degree of culpability is the same concerning fact and law, and in these cases, the Supreme Court often does not find it necessary to decide whether it is one or the other section that applies.
In prohibitions that require intent, the situation is different. Here, the mistake will lead to unconditional exemption from punishment if it is attributed under § 42 (factual mistake), whereas only the excusable mistake leads to acquittal if it is attributed under § 57 (mistake of law).
§ 57 applies not only in the case of a mistake about laws and regulations of general scope but also about special rules for a limited area or group, e.g., for a municipality or a street. It is irrelevant how the legal rule is expressed - normally it is through written words, but it can also be through signs or signals.
Situational Mistake and Normative Mistake
In legal practice, there is often talk of "situational mistake" as opposed to "normative mistake," which falls under § 57. In Danish and Swedish law, the terms "non-genuine mistake of law" and "genuine mistake of law" are used.
Attempts have been made to formulate general rules for the distinction, but in practice, this has proven difficult. It is not possible to operate with a conceptual distinction between the two types of mistake of law. The issue must therefore be resolved by interpreting the specific prohibition based on wording and real considerations.
Specific Cases of Mistake of Law
Mistake About Prejudicial Legal Matters
A mistake about the existence of the right or legal relationship that the prohibition is intended to protect is usually judged according to § 42, not § 57, regardless of whether the mistake is due to the perpetrator being mistaken about factual circumstances or a legal rule. This is referred to as a mistake about prejudicial legal matters in such cases.
This particularly applies to:
Theft crimes where the person is acting in good faith regarding their right and lacks intent for gain
Violation of another person's rights through illegal hunting or fishing
Breach of contractual obligations where contract breaches are exceptionally made punishable
Family law relationships
There are two main reasons for this special treatment:
In mistake about a prejudicial legal matter, the perpetrator may violate an interest they are not aware exists, giving the action a completely different character.
The consideration of the prohibition's effectiveness is not as prominent in legal rules that only have peripheral importance for the prohibition's scope.
Mistake about public law obligations, e.g., on accounting obligations, military service, or mandatory tax withholding, have generally not been treated in the same way as mistakes about private law matters, but it is difficult to extract a general rule from practice.
Legal Concepts in the Description of Acts in Prohibitions
What has been said about prejudicial legal matters does not apply to other cases where the law uses expressions with a legal content in its description of acts, e.g., "public official," "document," "punishable act," "possession," etc. It is not required for intent that the perpetrator is aware that the legal characterization inherent in the expression applies in the given case.
For example, someone who uses violence against a teacher can be punished under § 127 even if they do not know that a teacher is a public official in the sense of the law. The designation "public official" should be considered a collective term for the groups of people protected by the prohibition, not a prejudicial legal matter.
Conclusion
Mistake of law is a complex and important topic in criminal law. The main rule is that only excusable mistake of law—one that is not even negligent—can exempt from criminal liability. In practice, strict requirements are imposed for a mistake of law to be considered excusable, especially for those engaged in professional activities.
The boundary between factual mistake (§ 42) and mistake of law (§ 57) can be difficult to draw, particularly when it comes to prejudicial legal matters. Legal practice has developed certain guidelines, but they cannot be summarized in simple formulas. The decisive factor often becomes a holistic assessment of the action and whether the mistake of law makes the action itself justifiable.
