§ 12.01 Putting Mistake-of-Fact in Context

§ 12.01 Putting Mistake-of-Fact in Context¹

D1, a hunter, shoots and kills V1, believing he is killing a wild animal. D2 has non-consensual sexual intercourse with V2, mistakenly believing that V2 consented. D3 carries away property belonging to V3, incorrectly thinking that he has permission to take it. D4 drives above the speed limit because his speedometer is inaccurate.

In each of these cases the actor has caused the proscribed social harm. Looking only at their external behavior, one might also initially infer that the defendants intended to cause the harms inflicted. In fact, however, each actor was either unaware of, or mistaken about, a fact pertaining to an element of the offense for which he might be prosecuted. D1 did not know that he was shooting a human being, yet the death of a human being is an element of the offense of murder; D2 erroneously believed that V2 was willing to have sexual intercourse with him, which, if true, would have negated the "lack of consent" element of rape; D3 believed that he had the right to take V3's property, which, if true, would mean that he did not intend to steal the property; and D4 did not know that he was driving above the speed limit, the basis of the traffic offense.

This chapter considers why and when a mistake (or ignorance²) of a fact relating to an element³ of the offense exculpates an actor for the social harm he has caused. As will become evident, the common law's resolution of this issue is complicated. The Model Penal Code's solution is nicely straightforward.

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Notes:

^[1] See generally George Fletcher, Rethinking Criminal Law §§ 9.1-9.3.3 (1978); Rollin M. Perkins, Ignorance and Mistake in Criminal Law, 88 U. Pa. L. Rev. 35 (1939); Kenneth W. Simons, Mistake and Impossibility, Law and Fact, and Culpability: A Speculative Essay, 81 J. Crim. L. & Criminology 447 (1990).

^[2] "Ignorance" and "mistake" are not synonyms. "Ignorance" implies a total lack of knowledge—a blank mind—regarding the matter under consideration, whereas "mistake" suggests a wrong belief about the matter. Because...