Excusing Mistakes of Law

Abstract

Even a cursory look at the criminal law will lead one to realize that despite the old adage, a person who has a mistaken belief about the law can, in our system at least, be excused from criminal liability on those grounds. There are whole categories of legal mistake that can, at least under certain conditions, excuse a defendant from criminal liability. To give just one example, consider the British case of Regina v. Smith. With his landlord’s permission, the defendant installed some speaker wire behind a wall in an apartment he was renting. When it came time to move out, he disconnected the wire. He was charged with the crime of damaging property belonging to another, a crime that requires the defendant to intend such damage, or to be reckless with respect to it. He falsely believed that the speaker wire belonged to him, when in fact the law granted it, in such cases, to the landlord. Things attached to a wall belonged to the tenant; things installed behind them, to the landlord. But Smith was mistaken about the legal rule. After an appeal, the defendant was acquitted; his mistaken belief about the law was enough to excuse him. So, when understood as a descriptive claim, the slogan that ignorance of the law is no excuse is simply false. Further, when the slogan is understood normatively — as a claim to the effect that no one who is ignorant of the law should, on those grounds, be excused — it is false as well. After all, the right verdict was reached in Smith, and for the right reason. But Smith, and other cases like it, does not seem to invalidate the thought that lies behind the slogan. Smith’s mistake was not quite of the sort that we think it is attractive but mistaken to take as excusing him from criminal liability. There still seems, that is, a grain of truth to the slogan. This paper’s aim is not to defend the claim that mistakes of law never excuse; that claim is simply false. Rather, the paper aims to vindicate the claim by identifying the truth that is groped for but not grasped by those who assert that ignorance of law is no excuse.