Also known as: mistakes of fact · factual mistake · mistake of fact doctrine
Written by attorneys · grounded in primary & secondary sources — see below
An erroneous belief about an existing fact that is material to a legal determination. The belief must concern a fact whose existence or nonexistence can be established by objective evidence rather than a prediction, value judgment, or legal conclusion.
Maria Morales, a bank teller, saw a customer reach inside a bulky jacket after an alarm light flashed. Believing the customer was drawing a weapon, she tackled him. The customer was only retrieving an envelope of cash. Because her belief rested on a reasonable mistake of fact about the customer's actions, she remains privileged to use force.
Ming Ma executed a will leaving his donor-advised account at Helping Hands Fund to a charity. He maintained two accounts under different emails but referred to them collectively as his account for the charity. Clear and convincing evidence showed the omission resulted from a mistake of fact about the number of accounts. The court reforms the will to include both accounts.
Select any source to read its text and confirm it supports the definition.
Melissa Mills created a trust directing distributions to her niece. Drafting documents showed she believed the niece's name was spelled differently and that the trust included an additional parcel of land. Clear and convincing evidence established that a mistake of fact affected the terms. The court reforms the trust to match her actual intention.
An officer prepared a warrant describing a search for weapons but listed the wrong address due to a clerical transposition of numbers. The officers executed the warrant at the correct location they intended. The mistake of fact in the warrant description does not destroy qualified immunity when the officers' conduct was otherwise reasonable.
Miranda Morales sold a cow to Marcus Mitchell believing the animal was barren. Both parties relied on the cow's history and appearance. After the sale the cow delivered a calf, revealing it had been pregnant at the time of the contract. The mutual mistake of fact about the cow's condition permits rescission.
Marco Marquez engaged in sexual intercourse with a partner who had previously consented to similar activity. He honestly believed she remained willing based on her conduct and statements. Evidence later showed she had withdrawn consent. Because his mistake of fact was reasonable and negated the required mental state, he is not guilty of rape.
A mistake of fact negates the required mental state when it shows the defendant lacked purpose, knowledge, belief, recklessness, or negligence as to a material element. The defense succeeds if the defendant's erroneous belief about existing facts prevents formation of the culpable state of mind.
Clear and convincing evidence must establish both that a mistake of fact affected specific terms of the document and what the donor's actual intention was. Direct evidence of intention contradicting the text may be considered.
Yes, when the defendant both honestly believed facts that would justify the use of force and a reasonable person in the same position would have held that belief. The privilege attaches even though the actual facts later prove the belief mistaken.
A mistake of fact concerns an existing objective fact ascertainable by evidence, such as the condition of property at the time of sale. A mistake of law concerns the legal effect or validity of a term and is generally not grounds for rescission unless it affects a material fact.
…time the contract is made, but must have been known to one or both of the parties. Where there is no warranty, there can be no mistake of fact when no such fact exists, or, if in existence, neither party knew of it, or could know of it; and that is precisely this case. If the owner of a Hambletonian horse had speeded him, and was…