Defense Versus Evidence

Defense Versus Evidence

A diagnosis of mental disease can enter a criminal trial through either of two doors. The door chosen decides the question the factfinder must answer, the party who carries the burden, and what success means. Through the first door, the defendant claims the insanity defense. Even if every element of the offense is proved, a mental disease or defect left the defendant without substantial capacity to appreciate the criminality of the conduct or to conform it to the law, and responsibility is therefore excluded. The Code classifies that claim as an affirmative defense, a ground for acquittal that the defendant raises apart from the elements the prosecution must prove.¹ Through the second door, the same kind of evidence is offered on some other issue, most often whether the defendant actually had the state of mind the offense requires. There the diagnosis is one fact among many bearing on whether the prosecution has carried its own burden.²

The burdens differ because the questions differ. On the evidence track, the defendant is presumed innocent until the government proves every element beyond a reasonable doubt.³ Mental-disease evidence offered on an element asks the factfinder only whether the prosecution's proof of that element survives it, and a reasonable doubt about a required mental state requires acquittal.⁴ The insanity claim operates after the elements, asking the law to excuse an offender who has otherwise been proved guilty. Because the defendant is the one seeking an exception to ordinary responsibility, a state may require the defendant who makes that claim to carry the burden of persuasion.⁵ The results differ accordingly. Success on the defense excuses a defendant who satisfied the elements, while success on the evidence track means the prosecution failed to prove an element of the charged offense.

The presumption of sanity connects the two tracks. It is the starting assumption that a defendant has the capacity for responsible conduct, including the capacity to form the mental state an offense requires. A state that assigns the insanity burden to defendants relies on that presumption, and a defendant who offers mental-disease evidence on mens rea is, in practical effect, trying to weaken it by a different route. That overlap explains why the Supreme Court treated the presumption of sanity as central in Clark v. Arizona when it considered whether a state may confine mental-disease evidence to the insanity defense.⁶ The three subsections here take the pieces in order: the insanity defense as an affirmative defense under § 4.03(1) and the § 4.01 standard, then the presumption of sanity, and then the latitude experts receive when their testimony is offered for the defense. The defense track comes first so that the reader can see exactly what the evidence track leaves out.

Insanity as Affirmative Defense

The defense track has a definite shape in the Code, and it begins with a classification. Section 4.03(1) makes a claim of mental disease or defect excluding responsibility an affirmative defense.⁸ The words excluding responsibility refer back to § 4.01(1), which supplies the measure: a person is not responsible if, as a result of mental disease or defect, he lacks substantial capacity either to appreciate the wrongfulness of his conduct or to conform it to the requirements of law.⁹ Applying that standard belongs to other readings. The question here is what kind of claim it is and what procedures come with it. An affirmative defense assumes that the prosecution has proved the elements of the offense and asks the law to excuse the defendant anyway. Texas follows the same structure, and in Williams v. State the Texas court of appeals described its insanity defense as one that excuses a defendant even though the prosecution has proved every element, including the culpable mental state, beyond a reasonable doubt.¹⁰ The federal statute likewise labels insanity an affirmative defense.¹¹

The reason insanity sits outside the elements appears in Leland v. Oregon. There the jury could return any of five verdicts: guilty of first-degree murder, second-degree murder, or manslaughter, each on proof beyond a reasonable doubt of its elements; not guilty if a reasonable doubt remained about any element; or not guilty by reason of insanity, which would have freed the defendant from responsibility for every one of those offenses.¹² The Court observed that a jury might find a defendant mentally incapable of premeditation and deliberation, and so not guilty of first-degree murder, without finding him legally insane.¹³ Oregon treated sanity as a separate issue, introduced by a special plea and decided by a special verdict, which is a finding made on that issue alone, with the burden on the defendant.¹⁴ Its statute also required notice of the purpose to show insanity and provided for commitment to an asylum after a verdict of not guilty by reason of insanity.¹⁵ The Court later explained in Patterson v. New York that once the facts constituting the crime are established beyond a reasonable doubt on all the evidence, including evidence of the defendant's mental state, a state may refuse to sustain the affirmative defense of insanity unless the defendant demonstrates it by a preponderance of the evidence.¹⁶ The principle is general, as Smith v. United States confirms for withdrawal from a conspiracy: an affirmative defense that does not negate an element places no constitutional duty on the government to overcome it beyond a reasonable doubt.¹⁷ The label alone does not fix who bears the burden of persuasion, however. When Patterson was decided, 22 jurisdictions placed the burden of proving insanity on the defendant and 28 placed the burden of disproving it on the prosecution.¹⁸

Two procedural features follow from the classification, and the first is notice. Under § 4.03(2), evidence of mental disease or defect excluding responsibility is inadmissible unless the defendant files a written notice of the purpose to rely on that defense when entering a not-guilty plea or within ten days afterward, or at a later time the court permits for good cause.¹⁹ The requirement works as a gate on the evidence, closing the door before any testimony begins, and it serves two functions. The defense turns on facts about the defendant's own mind that the prosecution cannot observe, so advance warning is the only way the government can prepare to meet it. The Code also ties its examination provision to the notice: once the defendant files notice of intention to rely on the defense, the court is to appoint at least one qualified psychiatrist to examine the defendant and report, including an opinion on how far the capacity to appreciate wrongfulness or to conform conduct was impaired at the time of the conduct.²⁰ A defendant who could produce a diagnosis for the first time in mid-trial would deprive the court of the chance to arrange that examination and leave the prosecution without an informed rebuttal.

The notice rule is textually tied to the defense. Section 4.03(2) speaks only of evidence of mental disease or defect excluding responsibility, while § 4.02(1) separately makes mental-disease evidence admissible whenever it is relevant to whether the defendant had a state of mind that is an element of the offense.²¹ The Code attaches no notice condition to § 4.02(1) evidence, so the notice rule does not by its terms reach a diagnosis offered only to cast doubt on purpose or knowledge. The same is true of other steps needed only to preserve an insanity defense, such as advance notice or a special plea: omitting them does not keep out evidence offered on the mental-state element.²²

The second feature attaches at the other end of the case. Under § 4.03(3), when a defendant is acquitted on the ground of mental disease or defect excluding responsibility, the verdict and the judgment must say so.²³ The label is needed because an ordinary acquittal and an insanity acquittal look identical unless the record distinguishes them, and they do not lead to the same place. Section 4.08(1) directs the court, after an acquittal on that ground, to order the defendant committed to the custody of the state's mental-health commissioner for placement in an appropriate institution for custody, care, and treatment.²⁴ Release is not automatic either. If the court is not satisfied that the committed person may safely be released, a hearing follows at which the burden rests on the committed person to prove that discharge or release is safe.²⁵ Across jurisdictions, an insanity acquittee who poses a danger to self or others is generally committed rather than freed.²⁶

An acquittal won on the evidence track has a different character. When mental-disease evidence raises a reasonable doubt about a required mental state, the result is a finding of not guilty of the offense charged. Often some lesser offense remains available, so the end point may be a sentence of imprisonment on the lesser conviction rather than commitment.²⁷ Nothing in that verdict is labeled as an excuse, and the commitment provision is written for an acquittal on the ground of mental disease or defect excluding responsibility, not for a failure of proof on an element.²⁸ The difference in consequence reflects the line the responsibility standard draws. The Code's drafters described the problem as locating the boundary between condemning an offender by conviction, where reprobation is present however the sentence is framed, and dispositions in which condemnation is absent even though restraint may be involved. For persons plainly beyond the restraining influence of the law, they reasoned, condemnation would be futile and unjust, though restraint may still be needed.²⁹ An insanity acquittal therefore carries that disposition through the special verdict and commitment, while a failure of proof says only that the prosecution did not establish an element of the offense charged.

The usual error on exam facts is to treat any psychiatric testimony in a criminal trial as an insanity claim and to import its procedures. The notice requirement and the special verdict attach only to the responsibility-excluding defense, so the first question is always what the testimony is offered to prove.

The Presumption of Sanity

The presumption of sanity, which links the two tracks of mental-disease evidence, has a definite content. At a minimum it presumes that a defendant has the capacity to form the mens rea needed for a verdict of guilt, along with the capacity for criminal responsibility that goes with it.³³ In Clark v. Arizona the Court described the presumption as universal in some variety or other and traced it to authorities such as Leland v. Oregon and M'Naghten's Case.³⁴ Its practical effect is to dispense with any requirement that the government include, as an element of every criminal charge, an allegation that the defendant had that capacity.³⁵ The reason is practical. Most defendants have the mental capacity that crimes assume, so a rule making the prosecution allege and prove capacity in every case would require proof of a fact that is almost never contested. Oregon's statute in Leland reflected that reasoning by adopting the prevailing doctrine that, since most people are sane, a defendant who wishes to avoid responsibility on the ground of insanity must establish it.³⁶ Even the dissent in Leland, which objected to Oregon's demand that the accused prove insanity beyond a reasonable doubt, accepted that states may use common sense in taking for granted that most people are sane and responsible for their acts.³⁷

A presumption is only as strong as the showing needed to overcome it, and this is where the presumption of sanity departs from the presumption of innocence. As applied to mens rea, the presumption of innocence has a fixed measure: the government must prove beyond a reasonable doubt that the defendant's state of mind was in fact what the charge states.³⁸ The presumption of sanity has no fixed measure. Its force varies across the many state and federal jurisdictions, and the Court has recognized considerable leeway for legislatures to set its strength by deciding what kind of evidence, and what degree of persuasiveness, is needed to overcome it.³⁹ Two different questions therefore arise whenever mental-disease evidence appears. One is whether the prosecution has proved the defendant's actual state of mind, which the Constitution answers uniformly. The other is how heavily the law presumes that the defendant was capable of having a state of mind at all, which a legislature may answer differently from its neighbors.

The presumption can be placed in issue at two points, and which point is involved determines how strong it turns out to be.⁴⁰ The first is the prosecution's burden to prove mens rea. A state may let the defendant introduce, and the factfinder consider, evidence of mental disease or incapacity for what it shows about whether the government has proved the required state of mind.⁴¹ Such evidence qualifies the probative force of other evidence that, standing alone, suggests the defendant actually formed the guilty state of mind. The Court's own illustration in Clark is a defendant with a mental disease who thinks all blond people are robots. That defendant could not have intended to kill a person when he shot a man with blond hair, even though he seemed to act like a man shooting another man.⁴² In states that treat such evidence like any other relevant evidence, it need only support what the factfinder regards as a reasonable doubt about the capacity to form, or the actual formation of, the mens rea, and that doubt requires acquittal of the charge.⁴³ The presumption's strength there is no greater than the strength of the abnormal-mind evidence needed to raise a reasonable doubt. The mechanism is simple: the prosecution carries the burden of proof beyond a reasonable doubt on the element, so evidence that leaves the factfinder in reasonable doubt defeats the proof, and the defendant has no burden of persuasion to satisfy.

The second point is the insanity defense. Insanity rules such as M'Naghten and its variants try to define the kinds of mental differences that overcome the presumption of sanity and excuse a defendant from customary criminal responsibility, even when the prosecution has proved every element beyond a reasonable doubt.⁴⁴ Here the presumption is as strong as the burden the defendant must carry, and jurisdictions set that burden very differently.⁴⁵ Oregon required the accused to prove insanity beyond a reasonable doubt, and in Leland the Court declined to hold that policy a violation of due process.⁴⁶ Texas begins with a presumption that the defendant is sane and intends the natural consequences of his acts, and it excuses the defendant only if he proves insanity by a preponderance of the evidence.⁴⁷ Oklahoma, as described in Ake v. Oklahoma, kept the presumption only until the defendant raised a reasonable doubt about sanity by sufficient evidence, after which the State had to prove sanity beyond a reasonable doubt.⁴⁸ The District of Columbia Circuit reached a similar result in Durham v. United States, holding that testimony of mental disorder was enough to keep the presumption from becoming conclusive and to place the burden of proving sanity on the government.⁴⁹

Such a presumption also has a procedural effect that explains why the burden matters. It belongs to a family of devices that let the prosecution satisfy its burden on a presumed fact by proving other facts, which in effect requires the defendant to produce some evidence contesting the presumed fact. Because they shift the burden of producing evidence in that way, these devices must satisfy due process requirements.⁵⁰ The two points at which the presumption is tested therefore differ in what they ask of the defendant, and the same evidence can produce opposite results depending on which point it is offered for.

The first point, mental-disease evidence aimed at the prosecution's mens rea burden, is the subject of the rest of this chapter. The next section takes up the Model Penal Code's rule on admitting such evidence, and the one after it turns to Clark, where the question was whether a state that confines this evidence to the insanity defense, and so lets the presumption of sanity operate at full strength on mens rea, violates due process. A common error on exam facts is to read the presumption as relieving the prosecution of its burden on the mental element. The presumption removes only the need to allege capacity as an element, and capacity is presumed while the actual state of mind is not. A defendant who offers mental-disease evidence on mens rea raises doubt about the element itself, and the prosecution's burden on that element stays where it was.⁵¹

Expert Latitude in Insanity Cases

When a defendant raises insanity, the trial usually turns on what psychiatric experts can tell the jury, and the law shapes the expert's role to fit that defense. In Ake v. Oklahoma the Court described why the role is so central: psychiatrists gather facts through examination and interviews, draw conclusions about the defendant's condition and its effect on behavior, and translate a diagnosis into terms jurors can use, which lay witnesses who merely describe symptoms cannot do.⁵³ Psychiatrists disagree widely among themselves, so the jury must resolve competing opinions on the evidence each side offers. The Court held that once an indigent defendant shows that sanity at the time of the offense will be a significant factor at trial, the State must assure access to a competent psychiatrist who will examine the defendant and help evaluate, prepare, and present the defense.⁵⁴ The expert is therefore the main vehicle of proof on this track, and that is why legislatures have written rules about how much the expert may say.

The Model Penal Code answers with a provision aimed at the expert's freedom to explain. Section 4.07(4) lets a psychiatrist or other expert who testifies in an insanity case make "any explanation reasonably serving to clarify his diagnosis and opinion," and it permits cross-examination on any matter bearing on the expert's competency, credibility, or the validity of the diagnosis or opinion.⁵⁵ New York's Criminal Procedure Law § 60.55(1) uses virtually identical wording, the Code being one of the sources from which New York's Penal Law derives, and the New York provision applies only in insanity-defense cases.⁵⁶ The drafters meant to remove artificial constraints so that experts could testify fully, in terms the jury can understand, about their conclusions and the grounds for them. The expert is not confined to an opinion on impairment of capacity and need not frame that opinion as an answer to a hypothetical question.⁵⁷ The reason follows from how a diagnosis is built. A clinician forms it from the defendant's own statements, witness accounts, police reports, hospital records, and neuropsychological and medical tests, so a bare conclusion stripped of those sources would give the jury nothing to weigh and the cross-examiner nothing to test. The touchstone of both provisions is reasonableness: the explanation must reasonably serve to clarify and support the diagnosis.⁵⁸

What an expert can usefully say also depends on the responsibility standard the testimony addresses. The Code's test asks whether the defendant lacked substantial capacity to appreciate the wrongfulness of the conduct or to conform it to the law, and because the test uses "appreciate" rather than "know," testimony about the emotional or affective side of the defendant's personality is clearly relevant to it.⁵⁹ An earlier formulation shows a narrower division of labor. Under the product test announced in Durham v. United States, the psychiatrist's principal function was to inform the jury of the character of the accused's mental disease or defect, and the jury then applied moral judgment to the ultimate question.⁶⁰ That test is a historical contrast and not current law, because the Code's drafters rejected it for the ambiguity of the word "product."⁶¹

The latitude has a boundary that matters on exam facts. It frees the expert to explain how this defendant's diagnosis was reached, and it operates on the insanity track. It does not by its terms decide whether the mental syndrome the expert invokes exists, or whether a psychological theory validly explains human behavior.⁶² New York's reading of its statute marks the line. The provision requires admission of evidence directly relating to the diagnosis, such as the results of diagnostic tests a clinician relied on, even where the Frye test, a general-acceptance screen for novel scientific evidence, might otherwise exclude it, yet the reasonableness standard does not completely supersede that screen.⁶³ The two are treated differently because of where the knowledge comes from. A diagnosis rests largely on clinical judgment formed from information particular to the patient, so the jury can assess it once it hears the basis. Whether a syndrome exists is a general claim about the world that does not change from patient to patient, and a reliability standard for such claims is not displaced by a provision written to let clinicians explain themselves. Examinees lose this point when they treat latitude to explain a diagnosis as an admission ticket for any scientific claim.

Everything in this section attaches to the insanity track. The expert's freedom to explain exists because the evidence is offered to show that responsibility was excluded, and the prosecution, for its part, must be given the opportunity to answer with its own psychiatric experts in rebuttal.⁶⁴ Rules and procedures therefore follow the purpose for which the evidence is offered. When the same diagnosis is offered to show instead that the prosecution failed to prove a required state of mind, a different set of rules governs. The next section takes up the Code's evidence rule for that purpose, and the section after it turns to Clark v. Arizona, where the question was whether a state may confine such evidence to the insanity defense.