Also known as: mistake-of-law defense · mistake of law · mistakes of law · ignorantia juris · ignorance of law
Written by attorneys — see sources below.
A defense in criminal prosecutions that excuses liability when a defendant's mistaken belief about the law negates the required mental state for an offense or when the defendant reasonably relied on an official statement of law later determined to be erroneous. The defense also applies when a criminal enactment was not known to the actor and had not been published or otherwise reasonably made available before the conduct. In tort, a parallel rule provides that a mistaken belief about legal rights does not relieve an actor of liability for trespass to chattels or conversion.
Maria Morales repossessed a delivery van from a defaulting customer after consulting an outdated statute that she believed granted her an immediate right to seize the vehicle without court process. The statute had been amended months earlier to require judicial approval. Morales's sincere but mistaken belief about the governing law did not prevent the customer from recovering damages for conversion of the van.
Mason McCarthy, a self-employed contractor, stopped withholding federal income taxes after studying several court decisions and concluding that wages were not taxable income under the Sixteenth Amendment. The jury accepted that McCarthy's beliefs were sincere even though objectively unreasonable. Because the tax statute required proof of willfulness, the mistake-of-law defense prevented conviction.
John L. Cheek has been employed as a pilot by American Airlines since 1973. He filed federal income tax returns through 1979 but ceased to file returns thereafter. Cheek claimed an increasing number of withholding allowances on his W-4 forms, eventually claiming 60 allowances by mid-1980, and for the years 1981 to 1984 indicated that he was exempt from federal income taxes. In 1983, he unsuccessfully sought a refund of all tax withheld by his employer in 1982. His income during this period far exceeded the minimum necessary to trigger the statutory filing requirement. As a result of these activities, Cheek was indicted for ten violations of federal law. He faced six counts of willfully failing to file a federal income tax return for the years 1980, 1981, and 1983 through 1986. He was also charged with three counts of willfully attempting to evade his income taxes for the years 1980, 1981, and 1983. Because of the allowances and exempt status claimed on his W-4 forms, American Airlines withheld substantially less than the amount of tax Cheek owed. He was further charged with one count of presenting a false claim to an agency of the United States. At trial, evidence established that between 1982 and 1986 Cheek was involved in at least four civil cases challenging aspects of the federal income tax system. In those cases, courts informed the plaintiffs that arguments such as not being a taxpayer, wages not being income, and the Sixteenth Amendment not authorizing an income tax were frivolous. Cheek also attended at least two criminal trials of persons charged with tax offenses. An attorney had advised Cheek in 1980 or 1981 that courts had rejected the claim that wages are not income. Cheek represented himself and testified that since 1978 he had attended seminars sponsored by a group believing the federal tax system is unconstitutional. He produced a letter from an attorney stating that the Sixteenth Amendment did not authorize a tax on wages and salaries but only on gain or profit. Cheek claimed he sincerely believed his actions were lawful based on this indoctrination and his own study. The trial court instructed the jury on willfulness as the voluntary and intentional violation of a known legal duty. It advised that an objectively reasonable good-faith misunderstanding would negate willfulness but mere disagreement would not. After several hours of deliberation, the jury sent out another note. It stated that it still could not reach a verdict because it was divided on whether Mr. Cheek honestly and reasonably believed that he was not required to pay income tax. The court gave supplemental instructions stating that a person's opinion that tax laws violate constitutional rights does not constitute good faith misunderstanding, and that an honest but unreasonable belief is not a defense. The jury convicted Cheek on all counts approximately two hours after the final instruction. Cheek appealed, arguing error in the jury instructions requiring objective reasonableness. The Seventh Circuit affirmed the convictions. The Supreme Court granted certiorari because the Seventh Circuit's interpretation conflicted with decisions of other Courts of Appeals.
Melanie Morris, a federal agent, obtained a warrant that mistakenly described the items to be seized as firearms rather than the actual target of drug records. She executed the warrant in good faith reliance on the magistrate's approval. The mistake of law regarding the warrant's facial validity did not support qualified immunity in the subsequent civil action.
In February 1997, a concerned citizen informed ATF Special Agent Jeff Groh that on multiple visits to the ranch of Joseph Ramirez and his family in Butte-Silver Bow County, Montana, the visitor had observed a large stock of weaponry including an automatic rifle, grenades, a grenade launcher, and a rocket launcher. Groh prepared and signed an application for a warrant to search the ranch for any automatic firearms or parts, destructive devices including grenades, grenade launchers, rocket launchers, and receipts pertaining to their purchase or manufacture. He supported the application with a detailed affidavit setting forth the basis for his belief that the listed items were concealed on the premises. Groh also completed a warrant form that, in the portion calling for a description of the person or property to be seized, contained a description of the respondents' two-story blue house rather than the stockpile of firearms. The warrant did not incorporate the application by reference. The magistrate judge signed the warrant form after reviewing the documents, and the affidavit was placed under seal. The day after the magistrate issued the warrant, Groh led a team of federal agents and local sheriff's deputies in executing the search on the Ramirez ranch while Joseph Ramirez was absent but his wife and children were present. The officers uncovered no illegal weapons or explosives. Groh gave Mrs. Ramirez a copy of the search warrant but not the sealed application. The following day he faxed respondents' attorney a copy of the page of the application listing the items to be seized. Respondents Joseph Ramirez and his family brought this action against Groh and the other officers under Bivens v. Six Unknown Fed. Narcotics Agents and 42 U.S.C. § 1983, alleging that the search violated their Fourth Amendment rights. The District Court entered summary judgment for all defendants on all claims. The Court of Appeals for the Ninth Circuit affirmed the judgment as to all defendants and claims except the Fourth Amendment claim against Groh, on which it reversed. The Supreme Court granted certiorari to review the Fourth Amendment and qualified immunity questions.
Mariam Mansour made repeated bank deposits just under $10,000 to avoid paperwork after her accountant assured her that the structuring statute applied only to drug proceeds. The Supreme Court held that the government must prove she knew the structuring itself was illegal. Her mistake about the legal prohibition defeated the willfulness element.
Waldemar Ratzlaf incurred a substantial gambling debt while playing blackjack at the High Sierra Casino in Reno, Nevada, in October 1988. The casino extended him one week to settle the $160,000 obligation. On the payment date, Ratzlaf returned with $100,000 in cash, prompting a casino official to explain the reporting requirements for cash transactions exceeding $10,000 and to recommend using a cashier's check. The casino arranged transportation and an escort to nearby banks for Ratzlaf. At the banks, Ratzlaf acquired several cashier's checks in amounts below $10,000 from different institutions to prevent the filing of currency transaction reports. He completed payment to the casino using these checks. The Ratzlafs engaged in additional similar transactions two months later, purchasing cashier's checks totaling $98,500 with cash and casino chips. Federal prosecutors charged Waldemar Ratzlaf and his wife Loretta with conspiracy and multiple counts of structuring currency transactions. Following a trial where the jury received instructions on the elements of the offense, the Ratzlafs were convicted on all counts. The Court of Appeals for the Ninth Circuit affirmed the convictions in 1992. The Supreme Court of the United States granted certiorari to consider the proper interpretation of the willfulness element in 31 U.S.C. § 5322(a).
Matthew Martinez possessed a semiautomatic rifle after receiving a written opinion from a licensed firearms dealer stating that the weapon fell outside the National Firearms Act's registration requirement. The Court required the government to prove Martinez knew of the registration duty. His good-faith mistake about the statute's scope negated the mens rea element.
The National Firearms Act imposes strict registration requirements on statutorily defined firearms, including machineguns. A machinegun is defined as any weapon which shoots, or can be readily restored to shoot, automatically more than one shot, without manual reloading, by a single function of the trigger. In 1986, Congress amended the Act to criminalize the mere possession of an unregistered machinegun, a violation punishable by up to ten years' imprisonment. In 1989, local police and Bureau of Alcohol, Tobacco and Firearms agents executed a search warrant at petitioner Steven Staples' home and recovered an AR-15 rifle. The AR-15 is the civilian version of the military's M-16 rifle and is manufactured with a metal stop on its receiver to prevent conversion to automatic fire. On Staples' rifle, however, the stop had been filed away, and the weapon had been assembled with an M-16 selector switch and several other M-16 internal parts, including a hammer, disconnector, and trigger. BATF agents tested the rifle and confirmed that it fired more than one shot with a single pull of the trigger. It was undisputed that the weapon was not registered as required by the statute. Staples maintained that the rifle had never been modified to fire automatically and that he had no knowledge that it was capable of doing so. At trial, he requested the District Court to instruct the jury that the Government must prove beyond a reasonable doubt that he knew the gun would fire fully automatically. The District Court rejected that request. Instead, it charged the jury that the Government need only prove the defendant knew he was dealing with a dangerous device of a type as would alert one to the likelihood of regulation. The jury returned a verdict of guilty, and the court sentenced Staples to five years' probation and a $5,000 fine. The Court of Appeals for the Tenth Circuit affirmed the conviction. The Supreme Court granted certiorari to resolve a conflict in the Courts of Appeals concerning the mens rea requirement under the statute.
Miguel Mendoza, a corrections officer, carried a firearm while off duty after reading the penal code exemption for peace officers and concluding it covered his position. The statute in fact excluded corrections officers from the exemption. Because the mistake concerned the legal scope of the defense rather than a fact, the court rejected the mistake-of-law claim and affirmed the conviction.
Defendant Marrero was a Federal corrections officer employed at a facility in Danbury, Connecticut. In 1977 he was arrested inside a Manhattan social club while carrying a loaded .38 caliber automatic pistol. At the time of arrest he asserted his Federal corrections officer status and maintained that he was authorized to carry the weapon without a permit. Marrero claimed that his belief rested on interpretations supplied by fellow officers and teachers together with the wording of the peace officer statutes themselves. The case had already moved through several procedural stages before trial. Marrero's pretrial motion to dismiss the indictment was granted at 94 Misc 2d 367. The Appellate Division reversed that order and reinstated the indictment by a divided vote at 71 AD2d 346. Marrero's subsequent appeal from the Appellate Division order lapsed and was dismissed. At trial Marrero sought to present evidence that his personal misunderstanding of the statutory definition of a peace officer excused his conduct. The trial court rejected the proffered defense, refused to charge the jury on the issue, and the jury returned a verdict convicting him of criminal possession of a weapon in the third degree. The Appellate Division affirmed the conviction.
The defense is available when a defendant reasonably relies on an official statement of law contained in a statute, administrative order, or interpretation by the public officer or body charged with administering the law, and that statement is later determined to be erroneous. The reliance must produce a belief that the conduct is lawful, and the mistake must negate the required mental state or be expressly recognized by the governing law as exculpatory.
…188, 191-193 (CA1 1985), we granted certiorari, 493 U. S. 1068 (1990). II The general rule that ignorance of the law or a mistake of law is no defense to criminal prosecution is deeply rooted in the American legal system. See, e. g. , United States v. Smith , 5 Wheat. 153, 182 (1820) (Livingston, J., dissenting); Barlow…
…of law." Ibid. In reversing the order, Justice Holmes stated the following for the Court: "It certainly is true that mere mistakes of law in the course of a trial are not to be corrected [by habeas corpus]. But if the case is that the whole proceeding is a mask — that counsel, jury, and judge were swept to the fatal end by an…
…law. See, e. g. , Creighton, supra . Our qualified immunity doctrine applies regardless of whether the officer's error is a mistake of law, a mistake
Yes, under the Model Penal Code approach a belief that conduct is not criminal is a defense when the enactment was not known to the actor and had not been published or otherwise reasonably made available before the conduct. The defense requires proof by a preponderance that the defendant lacked actual knowledge and that the government failed to provide reasonable notice.
A genuine and reasonable mistake about whether an item is legally controlled or whether conduct falls within a statutory exemption can negate the knowledge element when the offense requires awareness of that legal status. The defense succeeds if the mistake prevents the prosecution from proving the required culpable mental state beyond a reasonable doubt.
No, the defense requires reliance on an official statement from a governmental source charged with interpreting or enforcing the law. An anonymous online post or advice from a private party does not qualify, even if the defendant sincerely believed it, because the law does not recognize such sources as creating an exculpatory mistake of law.