Also known as: ignorance · mistake · ignorance of fact · mistake of fact · ignorance of law · mistake of law · mistake of fact defense · ignorance of law defense
Written by attorneys · grounded in primary & secondary sources — see below
A defense to criminal liability when the defendant's ignorance or mistake of fact or law negates the culpable mental state required for the offense. The defense fails if the defendant would still be guilty of another offense under the facts as the defendant supposed them to be.
Isaiah Ishikawa was charged with receiving stolen property. He believed the package contained only tools he had purchased. The court instructed the jury that if Isaiah's mistake negated the required knowledge element he must be acquitted.
Ivan Ivanov was prosecuted for drug trafficking. He believed the substance was a legal supplement. After the limitations period the court considered whether his mistake of fact would have negated the knowledge element required for conviction.
Ivy Ibarra was charged with arson. She claimed she started the fire by accident while cooking. The court admitted prior-act evidence to show absence of mistake because the evidence tended to prove she possessed the required culpable mental state.
Select any source to read its text and confirm it supports the definition.
Imran Iyer was charged with theft after taking property he believed he owned. The court instructed that if Imran's mistake of fact negated the intent to deprive another of property he must be acquitted of theft.
Ilana Isaacs was charged with forgery. She claimed she signed the document believing it was a different instrument. The court instructed the jury that if her mistake negated the required intent she must be acquitted.
Ian Iverson was charged with possessing a controlled substance. He believed the package contained only vitamins. The court instructed the jury that if the mistake negated the required knowledge element, Ian must be acquitted of that offense.
Ignorance or mistake is a defense if it negates the purpose, knowledge, belief, recklessness, or negligence required to establish a material element of the offense. The defense is unavailable if the defendant would still be guilty of another offense had the facts been as supposed.
No. Trespass requires only intentional entry onto land in another's possession. A mistaken belief about ownership or boundaries does not negate the intent to enter the physical space and therefore does not defeat liability.
A mistake of law is a defense only when the law provides that the resulting mental state itself constitutes a defense or when the mistake negates a required mental element such as knowledge of the law's existence.
…was not; he prepared the list of names by which the clerk filled up commissions and believed Ramsay's name was omitted by mistake. He believed none of the commissions for justices of the peace signed by Mr. Adams were recorded; after being prepared they were carried to Mr. Adams for signature and then back to the…