Criminal Law

3406. Mistake of Fact

The defendant is not guilty of <insert crime[s]> if (he/ she) did not have the intent or mental state required to commit the crime because (he/she) [reasonably] did not know a fact or [reasonably and] mistakenly believed a fact.

If the defendant's conduct would have been lawful under the facts as (he/she) [reasonably] believed them to be, (he/she) did not commit <insert crime[s]>.

If you find that the defendant believed that <insert alleged mistaken facts> [and if you find that belief was reasonable], (he/she) did not have the specific intent or mental state required for <insert crime[s]>.

If you have a reasonable doubt about whether the defendant had the specific intent or mental state required for <insert crime[s]>, you must find (him/her) not guilty of (that crime/those crimes).

Bench Notes

Instructional Duty

The court has a sua sponte duty to instruct on mistake of fact if substantial evidence supports this defense. (People v. Lucero (1988) 203 Cal.App.3d 1011, 1018 [250 Cal.Rptr. 354].) This instruction also must be given on request, if supported by the evidence. (People v. Goodman (1970) 8 Cal.App.3d 705, 709 [87 Cal.Rptr. 665], disapproved on other grounds by People v. Beagle (1972) 6 Cal.3d 441, 452 [99 Cal.Rptr. 313, 492 P.2d 1].)

If the defendant is charged with a general intent crime, the trial court must instruct with the bracketed language requiring that defendant's belief be both actual and reasonable.

If the intent at issue is specific criminal intent, do not use the bracketed language requiring the belief to be reasonable.

Mistake of fact is not a defense to the following crimes under the circumstances described below:

1. Involuntary manslaughter (People v. Velez (1983) 144 Cal.App.3d 558, 565-566 [192 Cal.Rptr. 686] [mistake of fact re whether gun could be fired]).

2. Furnishing marijuana to a minor (Health & Saf. Code, § 11352; People v. Lopez (1969) 271 Cal.App.2d 754, 760-762 [77 Cal.Rptr. 59]).

3. Selling narcotics to a minor (Health & Saf. Code, § 11353; People v. Williams (1991) 233 Cal.App.3d 407, 410-411 [284 Cal.Rptr. 454] [specific intent for the crime of selling narcotics to a minor is the intent to sell cocaine, not to sell it to a minor]).

4. Aggravated kidnapping of a child under the age of 14 (Pen. Code, § 208(b); People v. Magpuso (1994) 23 Cal.App.4th 112, 118 [28 Cal.Rptr.2d 206]).

5. Unlawful sexual intercourse or oral copulation by person 21 or older with minor under the age of 16 (Pen. Code, §§ 261.5(d), 288a(b)(2); People v. Scott (2000) 83 Cal.App.4th 784, 800-801 [100 Cal.Rptr.2d 70]).

6. Lewd and lascivious conduct with a child under the age of 14 (Pen. Code, § 288(a); People v. Olsen (1984) 36 Cal.3d 638, 645-646 [205 Cal.Rptr. 492, 685 P.2d 52]).


Instructional Requirements. Pen. Code, § 26(3).

Burden of Proof. People v. Mayberry (1975) 15 Cal.3d 143, 157 [125 Cal.Rptr. 745, 542 P.2d 1337].

Secondary Sources

1 Witkin & Epstein, California Criminal Law (3d ed. 2000) Defenses, § 39.

3 Millman, Sevilla & Tarlow, California Criminal Defense Practice, Ch. 73, Defenses and Justifications, § 73.06 (Matthew Bender).

Related Issues

Mistake of Fact Based on Involuntary Intoxication

A mistake of fact defense can be based on involuntary intoxication. (People v. Scott (1983) 146 Cal.App.3d 823, 829-833 [194 Cal.Rptr. 633].) In Scott, the court held that the defendant was entitled to an instruction on mistake of fact, as a matter of law, where the evidence established that he unknowingly and involuntarily ingested a hallucinogen. As a result he acted under the delusion that he was a secret agent in a situation where it was necessary to steal vehicles in order to save his own life and possibly that of the President. The court held that although defendant's mistake of fact was irrational, it was reasonable because of his delusional state and had the mistaken facts been true, his actions would have been justified under the doctrine of necessity. The court also stated that mistake of fact would not have been available if defendant's mental state had been caused by voluntary intoxication. (Id. at pp. 829-833; see also People v. Kelly (1973) 10 Cal.3d 565, 573 [111 Cal.Rptr. 171, 516 P.2d 875] [mistake of fact based on voluntary intoxication is not a defense to a general intent crime].)

Mistake of Fact Based on Mental Disease

Mistake of fact is not a defense to general criminal intent if the mistake is based on mental disease. (People v. Gutierrez (1986) 180 Cal.App.3d 1076, 1084 [225 Cal.Rptr. 885]; see People v. Castillo (1987) 193 Cal.App.3d 119, 124-125 [238 Cal.Rptr. 207].) In Gutierrez, the defendant was charged with inflicting cruel injury on a child, a general intent crime, because she beat her own children under the delusion that they were evil birds she had to kill. The defendant's abnormal mental state was caused in part by mental illness. (People v. Gutierrez, supra, 180 Cal.App.3d at pp. 1079-1080.) The court concluded that evidence of her mental illness was properly excluded at trial because mental illness could not form the basis of her mistake of fact defense. (Id. at pp. 1083-1084.)

(New January 2006)