Voluntary Act Versus Mental State

Voluntary Act Versus Mental State

The voluntary act requirement in § 2.01 of the Model Penal Code asks what a person's body did, or failed to do, and whether the person controlled it. It says nothing about what the person meant by the movement. The Code assigns that second inquiry to § 2.02(1), under which a person is not guilty of an offense unless he acted purposely, knowingly, recklessly, or negligently, as the law may require, with respect to each material element of the offense.¹ A prosecution therefore has two separate showings to make, and most crimes also require a causal link between the conduct and the harm and a concurrence between the guilty mind and the act.² The Code's own definitions keep the showings apart, because an act means any bodily movement, whether voluntary or involuntary. A movement can therefore be an act in the Code's sense before anyone has asked whether it was voluntary or what state of mind went with it.³

Each requirement guards against a different mistake, which is why neither can stand in for the other. The act requirement ensures that liability rests on conduct the person controlled, since a threat of punishment cannot deter a movement the person did not choose, and a person who did not choose it made no wrongful decision to condemn.⁴ The mental-state requirement ensures that the person was blameworthy in doing what he did, reflecting the settled idea that crime joins a wrongdoing hand to a guilty mind and that wrongdoing must be conscious to be criminal.⁵ A defendant whose fist swings by choice has performed a voluntary act, and that act settles nothing about the second requirement. Purpose, the most demanding mental state, exists only when it is the defendant's conscious object to engage in conduct of that nature or to cause the result.⁶

The same separation shows where voluntary intoxication belongs. A person who drinks before acting still moves by his own effort, which is why the involuntary-movement categories do not reach him, so the significance of the drinking arises, if at all, on the mental-state side. That was the setting in Montana v. Egelhoff, which concerned a Montana statute directing that voluntary intoxication may not be taken into consideration in determining the existence of a mental state that is an element of an offense.⁷

The practical danger of blurring the two requirements appears in Sandstrom v. Montana. Sandstrom confessed to killing Annie Jessen and was charged with deliberate homicide, which required that he purposely or knowingly caused her death. His lawyer told the jury that he admitted the killing but did not act purposely or knowingly, relying on two court-appointed mental health experts who described a personality disorder aggravated by alcohol.⁸ The prosecution asked for, and the jury received, an instruction that the law presumes a person intends the ordinary consequences of his voluntary acts.⁹ The Court looked at how a reasonable juror could have taken those words: the jurors were told only that the law presumed intent, not that they had a choice, and the State itself conceded a risk that jurors who had found the act voluntary would read the instruction as automatically directing a finding of intent.¹⁰ The concern was that a juror could treat the instruction as conclusive, or as placing on the defendant the burden of persuasion on intent. Either reading would let proof of a voluntary act stand in for proof of intent, an element the Fourteenth Amendment requires the State to prove beyond a reasonable doubt.¹¹

The rules governing presumptions and burdens of proof receive fuller treatment elsewhere, and the lesson needed here is narrower. A finding that an act was voluntary is a finding about conduct, and the intent the offense requires remains its own element to be established.

The opposite error is equally unavailable. A guilty mind with no act is not criminal, because the criminal law reaches voluntary action and leaves thinking alone. Two practical reasons support that line: it is extremely hard to know what a person is thinking, and most people would otherwise be exposed to liability for their passing fantasies about wrongdoing.¹²

The pairing of act and mental state carries over to omissions. Where the law makes a failure to act a basis for liability, that failure must still be joined to a culpable mental state, and proving what a defendant was thinking while failing to act can be harder than proving it for an affirmative act.¹³ The next section takes up when an omission can serve as the act at all. Students lose this issue when they treat a finding of voluntariness as proof of intent, since voluntariness answers only whether the movement was the person's own.