Mr. Justice White
delivered the opinion of the Court.
The question here is the constitutionality under the Fourteenth Amendment’s Due Process Clause of burdening the defendant in a New York State murder trial with proving the affirmative defense of extreme emotional disturbance as defined by New York law.
I
After a brief and unstable marriage, the appellant, Gordon Patterson, Jr., became estranged from his wife, Roberta. Roberta resumed an association with John Northrup, a neighbor to whom she had been engaged prior to her marriage to appellant. On December 27, 1970, Patterson borrowed a rifle from an acquaintance and went to the residence of his father-in-law. There, he observed his wife through a window in a state of semiundress in the presence of John Northrup. He entered the house and killed Northrup by shooting him twice in the head.
Patterson was charged with second-degree murder. In New York there are two elements of this crime: (1) “intent to cause the death of another person”; and (2) “caus[ing] the death of such person or of a third person.” N. Y. Penal Law § 125.25 (McKinney 1975) , Malice aforethought is not an element of the crime. In addition, the State permits a person accused of murder to raise an affirmative defense that he “acted under the influence of extreme emotional disturbance for which there was a reasonable explanation or excuse.”
New York also recognizes the crime of manslaughter. A person is guilty of manslaughter if he intentionally kills another person “under circumstances which do not constitute murder because he acts under the influence of extreme emotional disturbance.” Appellant confessed before trial to killing Northrup, but at trial he raised the defense of extreme emotional disturbance.
The jury was instructed as to the elements of the crime of murder. Focusing on the element of intent, the trial court charged:
“Before you, considering all of the evidence, can convict this defendant or anyone of murder, you must believe and decide that the People have established beyond a reasonable doubt that he intended, in firing the gun, to kill either the victim himself or some other human being. . . .
“Always remember that you must not expect or require the defendant to prove to your satisfaction that his acts were done without the intent to kill. Whatever proof he may have attempted, however far he may have gone in an effort to convince you of his innocence or guiltlessness, he is not obliged, he is not obligated to prove anything. It is always the People's burden to prove bis guilt, and to prove that he intended to kill in this instance beyond a reasonable doubt.” App. A70-A71.
The jury was further instructed, consistently with New York law, that the defendant had the burden of proving his affirmative defense by a preponderance of the evidence. The jury was told that if it found beyond a reasonable doubt that appellant had intentionally killed Northrup but that appellant had demonstrated by a preponderance of the evidence that he had acted under the influence of extreme emotional disturbance, it had to find appellant guilty of manslaughter instead of murder.
The jury found appellant guilty of murder. Judgment was entered on the verdict, and the Appellate Division affirmed. While appeal to the New York Court of Appeals was pending, this Court decided Mullaney v. Wilbur, 421 U. S. 684 (1975), in which the Court declared Maine’s murder statute unconstitutional. Under the Maine statute, a person accused of murder could rebut the statutory presumption that he committed the offense with “malice aforethought” by proving that he acted in the heat of passion on sudden provocation. The Court held that this scheme improperly shifted the burden of persuasion from the prosecutor to the defendant and was therefore a violation of due process. In the Court of Appeals appellant urged that New York’s murder statute is functionally equivalent to the one struck down in Mullaney and that therefore his conviction should be reversed.
The Court of Appeals rejected appellant’s argument, holding that the New York murder statute is consistent with due process. 39 N. Y. 2d 288, 347 N. E. 2d 898 (1976). The Court distinguished Mullaney on the ground that the New York statute involved no shifting of the burden to the defendant to disprove any fact essential to the offense charged since the New York affirmative defense of extreme emotional disturbance bears no direct relationship to any element of murder. This appeal ensued, and we noted probable jurisdiction. 429 U.S. 813 (1976). We affirm.
II
It goes without saying that preventing and dealing with crime is much more the business of the States than it is of the Federal Government, Irvine v. California, 347 U. S. 128, 134 (1954) (plurality opinion), and that we should not lightly construe the Constitution so as to intrude upon the administration of justice by the individual States. Among other things, it is normally “within the power of the State to regulate procedures under which its laws are carried out, including the burden of producing evidence and the burden of persuasion,” and its decision in this regard is not subject to proscription under the Due Process Clause unless “it offends some principle of justice so rooted in the traditions and conscience of our people as to be ranked as fundamental.” Speiser v. Randall, 357 U. S. 513, 523 (1958); Leland v. Oregon, 343 U. S. 790, 798 (1952); Snyder v. Massachusetts, 291 U. S. 97, 105 (1934).
In determining whether New York’s allocation to the defendant of proving the mitigating circumstances of severe emotional disturbance is consistent with due process, it is therefore relevant to note that this defense is a considerably expanded version of the common-law defense of heat of passion on sudden provocation and that at common law the burden of proving the latter, as well as other affirmative defenses — indeed, “all... circumstances of justification, excuse or alleviation” — rested on the defendant. 4 W. Blackstone, Commentaries *201; M. Foster, Crown Law 255 (1762); Mullaney v. Wilbur, supra, at 693-694. This was the rule when the Fifth Amendment was adopted, and it was the American rule when the Fourteenth Amendment was ratified. Commonwealth v. York, 50 Mass. 93 (1845).
In 1895 the common-law view was abandoned with respect to the insanity defense in federal prosecutions. Davis v. United States, 160 U. S. 469 (1895). This ruling had wide impact on the practice in the federal courts with respect to the burden of proving various affirmative defenses, and the prosecution in a majority of jurisdictions in this country sooner or later came to shoulder the burden of proving the sanity of the accused and of disproving the facts constituting other affirmative defenses, including provocation. Davis was not a constitutional ruling, however, as Leland v. Oregon, supra, made clear.
At issue in Leland v. Oregon was the constitutionality under the Due Process Clause of the Oregon rule that the defense of insanity must be proved by the defendant beyond a reasonable doubt. Noting that Davis “obviously establish [ed] no constitutional doctrine,” 343 U. S., at 797, the Court refused to strike down the Oregon scheme, saying that the burden of proving all elements of the crime beyond reasonable doubt, including the elements of premeditation and deliberation, was placed on the State under Oregon procedures and remained there throughout the trial. To convict, the jury was required to find each element of the crime beyond a reasonable doubt, based on all the evidence, including the evidence going to the issue of insanity. Only then was the jury “to consider separately the issue of legal sanity per se . . . .” Id., at 795. This practice did not offend the Due Process Clause even though among the 20 States then placing the burden of proving his insanity on the defendant, Oregon was alone in requiring him to convince the jury beyond a reasonable doubt.
In 1970, the Court declared that the Due Process Clause “protects the accused against conviction except upon proof beyond a reasonable doubt of every fact necessary to constitute the crime with which he is charged.” In re Winship, 397 U. S. 358, 364 (1970). Five years later, in Mullaney v. Wilbur, 421 U. S. 684 (1975), the Court further announced that under the Maine law of homicide, the burden could not constitutionally be placed on the defendant of proving by a preponderance of the evidence that the killing had occurred in the heat of passion on sudden provocation. The Chief Justice and Me. Justice Rehnquist, concurring, expressed their understanding that the Mullaney decision did not call into question the ruling in Leland v. Oregon, supra, with respect to the proof of insanity.
Subsequéntly, the Court confirmed that it remained constitutional to burden the defendant with proving his insanity defense when it dismissed, as not raising a substantial federal question, a case in which the appellant specifically challenged the continuing validity of Leland v. Oregon. This occurred in Rivera v. Delaware, 429 U. S. 877 (1976), an appeal from a Delaware conviction which, in reliance on Leland, had been affirmed by the Delaware Supreme Court over the claim that the Delaware statute was unconstitutional because it burdened the defendant with proving his affirmative defense of insanity by a preponderance of the evidence. The claim in this Court was that Leland had been overruled by Winship and Mullaney. We dismissed the appeal as not presenting a substantial federal question. Cf. Hicks v. Miranda, 422 U. S. 332, 344 (1975).
Ill
We cannot conclude that Patterson’s conviction under the New York law deprived him of due process of law. The crime of murder is defined by the statute, which represents a recent revision of the state criminal code, as causing the death of another person with intent to do so. The death, the intent to kill, and causation are the facts that the State is required to prove beyond a reasonable doubt if a person is to be convicted of murder. No further facts are either presumed or inferred in order to constitute the crime. The statute does provide an affirmative defense — that the defendant acted under the influence of extreme emotional disturbance for which there was a reasonable explanation — which, if proved by a preponderance of the evidence, would reduce the crime to manslaughter, an offense defined in a separate section of the statute. It is plain enough that if the intentional killing is shown, the State intends to deal with the defendant as a murderer unless he demonstrates the mitigating circumstances.
Here, the jury was instructed in accordance with the statute, and the guilty verdict confirms that the State successfully carried its burden of proving the facts of the crime beyond a reasonable doubt. Nothing in the evidence, including any evidence that might have been offered with respect to Patterson’s mental state at the time of the crime, raised a reasonable doubt about his guilt as a murderer; and clearly the evidence failed to convince the jury that Patterson’s affirmative defense had been made out. It seems to us that the State satisfied the mandate of Winship that it prove beyond a reasonable doubt “every fact necessary to constitute the crime with which [Patterson was] charged.” 397 U. S., at 364.
In convicting Patterson under its murder statute, New York did no more than Leland and Rivera permitted it to do without violating the Due Process Clause. Under those cases, once the facts constituting a crime are established beyond a reasonable doubt, based on all the evidence including the evidence of the defendant’s mental state, the State may refuse to sustain the affirmative defense of insanity unless demonstrated by a preponderance of the evidence.
The New York law on extreme emotional disturbance follows this pattern. This affirmative defense, which the Court of Appeals described as permitting “the defendant to show that his actions were caused by a mental infirmity not arising to the level of insanity, and that he is less culpable for having committed them,” 39 N. Y. 2d, at 302, 347 N. E. 2d, at 907, does not serve to negative any facts of the crime which the State is to prove in order to convict of murder. It constitutes a separate issue on which the defendant is required to carry the burden of persuasion; and unless we are to overturn Leland and Rivera, New York has not violated the Due Process Clause, and Patterson’s conviction must be sustained.
We are unwilling to reconsider Leland and Rivera. But even if we were to hold that a State must prove sanity to convict once that fact is put in issue, it would not necessarily follow that a State must prove beyond a reasonable doubt every fact, the existence or nonexistence of which it is willing to recognize as an exculpatory or mitigating circumstance affecting the degree of culpability or the severity of the punishment. Here, in revising its criminal code, New York provided the affirmative defense of extreme emotional disturbance, a substantially expanded version of the older heat-of-passion concept; but it was willing to do so only if the facts making out the defense were established by the defendant with sufficient certainty. The State was itself unwilling to undertake to establish the absence of those facts beyond a reasonable doubt, perhaps fearing that proof would be too difficult and that too many persons deserving treatment as murderers would escape that punishment if the evidence need merely raise a reasonable doubt about the defendant’s emotional state. It has been said that the new criminal code of New York contains some 25 affirmative defenses which exculpate or mitigate but which must be established by the defendant to be operative. The Due Process Clause, as we see it, does not put New York to the choice of abandoning those defenses or undertaking to disprove their existence in order to convict of a crime which otherwise is within its constitutional powers to sanction by substantial punishment.
The requirement of proof beyond a reasonable doubt in a criminal case is “bottomed on a fundamental value determination of our society that it is far worse to convict an innocent man than to let a guilty man go free.” Winship, 397 U. S., at 372 (Harlan, J., concurring). The social cost of placing the burden on the prosecution to prove guilt beyond a reasonable doubt is thus an increased risk that the guilty will go free. While it is clear that our society has willingly chosen to bear a substantial burden in order to protect the innocent, it is equally clear that the risk it must bear is not without limits; and Mr. Justice Harlan’s aphorism provides little guidance for determining what those limits are. Due process does not require that every conceivable step be taken, at whatever cost, to eliminate the possibility of convicting an innocent person. Punishment of those found guilty by a jury, for example, is not forbidden merely because there is a remote possibility in some instances that an innocent person might go to jail.
It is said that the common-law rule permits a State to punish one as a murderer when it is as likely as not that he acted in the heat of passion or under severe emotional distress and when, if he did, he is guilty only of manslaughter. But this has always been the case in those jurisdictions adhering to the traditional rule. It is also very likely true that fewer convictions of murder would occur if New York were required to negative the affirmative defense at issue here. But in each instance of a murder conviction under the present law, New York will have proved beyond a reasonable doubt that the defendant has intentionally killed another person, an act which it is not disputed the State may constitutionally criminalize and punish. If the State nevertheless chooses to recognize a factor that mitigates the degree of criminality or punishment, we think the State may assure itself that the fact has been established with reasonable certainty. To recognize at all a mitigating circumstance does not require the State to prove its nonexistence in each case in which the fact is put in issue, if in its judgment this would be too cumbersome, too expensive, and too inaccurate.
We thus decline to adopt as a constitutional imperative, operative countrywide, that a State must disprove beyond a reasonable doubt every fact constituting any and all affirmative defenses related to the culpability of an accused. Traditionally, due process has required that only the most basic procedural safeguards be observed; more subtle balancing of society’s interests against those of the accused have been left to the legislative branch. We therefore will not disturb the balance struck in previous cases holding that the Due Process Clause requires the prosecution to prove beyond a reasonable doubt all of the elements included in the definition of the offense of which the defendant is charged. Proof of the nonexistence of all affirmative defenses has never been constitutionally required; and we perceive no reason to fashion such a rule in this case and apply it to the statutory defense at issue here.
This view may seem to permit state legislatures to reallocate burdens of proof by labeling as affirmative defenses at least some elements of the crimes now defined in their statutes. But there are obviously constitutional limits beyond which the States may not go in this regard. “[I]t is not within the province of a legislature to declare an individual guilty or presumptively guilty of a crime.” McFarland v. American Sugar Rfg. Co., 241 U. S. 79, 86 (1916). The legislature cannot “validly command that the finding of an indictment, or mere proof of the identity of the accused, should create a presumption of the existence of all the facts essential to guilt.” Tot v. United States, 319 U. S. 463, 469 (1943). See also Speiser v. Randall, 357 U. S., at 523-525. Morrison v. California, 291 U. S. 82 (1934), also makes the point with sufficient clarity.
Long before Winship, the universal rule in this country was that the prosecution must prove guilt beyond a reasonable doubt. At the same time, the long-accepted rule was that it was constitutionally permissible to provide that various affirmative defenses were to be proved by the defendant. This did not lead to such abuses or to such widespread redefinition of crime and reduction of the prosecution's burden that a new constitutional rule was required. This was not the problem to which Winship was addressed. Nor does the fact that a majority of the States have now assumed the burden of disproving affirmative defenses — for whatever reasons — mean that those States that strike a different balance are in violation of the Constitution.
IY
It is urged that Mullaney v. Wilbur necessarily invalidates Patterson’s conviction.. In Mullaney the charge was murder, which the Maine statute defined as the unlawful killing of a human being “with malice aforethought, either express or implied.” The trial court instructed the jury that the words “malice aforethought” were most important because “malice aforethought is an essential and indispensable element of the crime of murder.” Malice, as the statute indicated and as the court instructed, could be implied and was to be implied from “any deliberate, cruel act committed by one person against another suddenly ... or without a considerable provocation,” in which event an intentional killing was murder unless by a preponderance of the evidence it was shown that the act was committed “in the heat of passion, on sudden provocation.” The instructions emphasized that “ 'malice aforethought and heat of passion on sudden provocation are two inconsistent things’; thus, by proving the latter the defendant would negate the former.” 421 U. S., at 686-687 (citation omitted).
Wilbur’s conviction, which followed, was affirmed. The Maine Supreme Judicial Court held that murder and manslaughter were varying degrees of the crime of felonious homicide and that the presumption of malice arising from the unlawful killing was a mere policy presumption operating to cast on the defendant the burden of proving provocation if he was to be found guilty of manslaughter rather than murder — a burden which the Maine law had allocated to him at least since the mid-1800’s.
The Court of Appeals for the First Circuit then ordered that a writ of habeas corpus issue, holding that the presumption unconstitutionally shifted to the defendant the burden of proof with respect to an essential element of the crime. The Maine Supreme Judicial Court disputed this interpretation of Maine law in State v. Lafferty, 309 A. 2d 647 (1973), declaring that malice aforethought, in the sense of premeditation, was not an element of the crime of murder and that the federal court had erroneously equated the presumption of malice with a presumption of premeditation.
“Maine law does not rely on a presumption of 'premeditation’ (as Wilbur v. Mullaney assumed) to prove an essential element of unlawful homicide punishable as murder. Proof beyond a reasonable doubt of 'malice aforethought’ (in the sense of 'premeditation’) is not essential to conviction. . . . [T]he failure of the State to prove 'premeditation’ in this context is not fatal to such a prosecution because, by legal definition under Maine law, a killing becomes unlawful and punishable as 'murder’ on proof of 'any deliberate, cruel act, committed by one person against another, suddenly without any, or without a considerable provocation.’ State v. Neal, 37 Me. 468, 470 (1854). Neal has been frequently cited with approval by our Court.” Id., at 664-665. (Emphasis added; footnote omitted.)
When the judgment of the First Circuit was vacated for reconsideration in the light of Lafferty, that court reaffirmed its view that Wilbur’s conviction was unconstitutional. This Court, accepting the Maine court’s interpretation of the Maine law, unanimously agreed with the Court of Appeals that Wilbur’s due process rights had been invaded by the presumption casting upon him the burden of proving by a preponderance of the evidence that he had acted in the heat ,of passion upon sudden provocation.
Mullaney’s holding, it is argued, is that the State may not permit the blameworthiness of an act or the severity of punishment authorized for its commission to depend on the presence or absence of an identified fact without assuming the burden of proving the presence or absence of that fact, as the case may be, beyond a reasonable doubt. In our view, the Mullaney holding should not be so broadly read. The concurrence of two Justices in Mullaney was necessarily contrary to such a reading; and a majority of the Court refused to so understand and apply Mullaney when Rivera was dismissed for want of a substantial federal question.
Mullaney surely held that a State must prove every ingredient of an offense beyond a reasonable doubt, and that it may not shift the burden of proof to the defendant by presuming that ingredient upon proof of the other elements of the offense. This is true even though the State’s practice, as in Maine, had been traditionally to the contrary. Such shifting of the burden of persuasion with respect to a fact which the State deems so important that it must be either proved or presumed is impermissible under the Due Process Clause.
It was unnecessary to go further in Mullaney. The Maine Supreme Judicial Court made it clear that malice aforethought, which was mentioned in the statutory definition of the crime, was not equivalent to premeditation and that the presumption of malice traditionally arising in intentional homicide cases carried no factual meaning insofar as premeditation was concerned. Even so, a killing became murder in Maine when it resulted from a deliberate, cruel act committed by one person against another, “suddenly without any, or without a considerable provocation.” State v. Lafferty, supra, at 665. Premeditation was not within the definition of murder; but malice, in the sense of the absence of provocation, was part of the definition of that crime. Yet malice, i. e., lack of provocation, was presumed and could be rebutted by the defendant only by proving by a preponderance of the evidence that he acted with heat of passion upon sudden provocation. In Mullaney we held that however traditional this mode of proceeding might have been, it is contrary to the Due Process Clause as construed in Winship.
As we have explained, nothing was presumed or implied against Patterson; and his conviction is not invalid under any of our prior cases. The judgment of the New York Court of Appeals is
Affirmed.
Mr. Justice Rehnquist took no part in the consideration or decision of this case.
References herein to the charge of “murder” under New York law are to this section. Cf. N. Y. Penal Law § 125.27 (McKinney 1975) (murder in the first degree).
Section 125.25 provides in relevant part:
“A person is guilty of murder in the second degree when:
“1. With intent to cause the death of another person, he causes the death of such person or of a third person; except that in any prosecution under this subdivision, it is an affirmative defense that:
“(a) The defendant acted under the influence of extreme emotional disturbance for which there was a reasonable explanation or excuse, the reasonableness of which is to be determined from the viewpoint of a person in the defendant's situation under the circumstances as the defendant believed them to be. Nothing contained in this paragraph shall constitute a defense to a prosecution for, or preclude a conviction of, manslaughter in the first degree or any other crime.”
Section 125.20 (2), N. Y. Penal Law § 125.20 (2) (McKinney 1975), provides:
“A person is guilty of manslaughter in the first degree when:
“2. With intent to cause the death of another person, he causes the death of such person or of a third person under circumstances which do not constitute murder because he acts under the influence of extreme emotional disturbance, as defined in paragraph (a) of subdivision one of section 125.25. The fact that homicide was committed under the influence of extreme emotional disturbance constitutes a mitigating circumstance reducing murder to manslaughter in the first degree and need not be proved in any prosecution initiated under this subdivision.”
Appellant also contended at trial that the shooting was accidental and that therefore he had no intent to kill Northrup. It is here undisputed, however, that the prosecution proved beyond a reasonable doubt that the killing was intentional.
The trial court’s instructions to the jury focused emphatically and repeatedly on the prosecution’s burden of proving guilt beyond a reasonable doubt.
“The burden of proving the guilt of a defendant beyond a reasonable doubt rests at all times upon the prosecution. A defendant is never obliged to prove his innocence.
“Before you can find a defendant guilty, you must be convinced that each and every element of the crime charged and his guilt has been established to your satisfaction by reliable and credible evidence beyond a reasonable doubt.” App. A48-A49.
In Hankerson v. North Carolina, post, p. 233, we hold, as did the New York Court of Appeals in the present case, that Mullaney is to be applied retroactively. The fact that Patterson was tried prior to our decision in Mullaney does not insulate this case from the principles of Mullaney.
See also F. Wharton, A Treatise on the Law of Evidence in Criminal Issues 240-269 (9th ed. 1884); H. Kelley, Criminal Law and Practice 124^128, 131 (1876); Fletcher, Two Kinds of Legal Rules: A Comparative Study of Burden-of-Persuasion Practices in Criminal Cases, 77 Yale L. J. 880, 882-884 (1968); Note, Affirmative Defenses After Mullaney v. Wilbur: New York’s Extreme Emotional Disturbance, 43 Brooklyn L. Rev. 171, 190 (1976).
York, which relied on American authorities dating back to the early 1800’s, confirmed that the common-law and prevailing American view was that the burden was on the defendant to prove provocation. York is said to have governed a half century of American burden-of-proof decisions in provocation and self-defense cases. Fletcher, supra, n. 7, at 903-904.
Meanwhile, the Court had explained that although the State could go too far in shifting the burden of proof to a defendant in a criminal case, the Due Process Clause did not invalidate every instance of burdening the defendant with proving an exculpatory fact. In Morrison v. California, 291 U. S. 82 (1934), a state law made it illegal for an alien ineligible for citizenship to own or possess land. Initially, in a summary dismissal for want of a substantial federal question, Morrison v. California, 288 U. S. 591 (1933), the Court held that it did not violate the Due Process Clause for the State to place on the defendant “the burden of proving citizenship as a defense,” 291 U. S., at 88, once the State’s evidence had shown that the defendant possessed the land and was a member of a race barred from citizenship. In the later Morrison case the Court reiterated and approved its previous summary holding, even though it struck down more drastic burden shifting permitted under another section of the statute. The Court said that its earlier per curiam ruling “was not novel”:
“The decisions are manifold that within limits of reason and fairness the burden of proof may be lifted from the state in criminal prosecutions and cast on a defendant. The limits are in substance these, that the state shall have proved enough to make it just for the defendant to be required to repel what has been proved with excuse or explanation, or at least that upon a balancing of convenience or of the opportunities for knowledge the shifting of the burden will be found to be an aid to the accuser without subjecting the accused to hardship or oppression. Cf. Wigmore, Evidence, Vol. 5, §§ 2486, 2512 and cases cited. Special reasons are at hand to make the change permissible when citizenship vel non is the issue to be determined. Citizenship is a privilege not due of common right. One who lays claim to it as his, and does this in justification or excuse of an act otherwise illegal, may fairly be called upon to prove his title good.” Id., at 88-89.
In ruling that in the other section of the statute then at issue the State had gone too far, the Court said:
“For a transfer of the burden, experience must teach that the evidence held to be inculpatory has at least a sinister significance (Yee Hem v. United States, [268 U. S. 178 (1925)]; Casey v. United States [276 U. S. 413 (1928)]), or if this at times be lacking, there must be in any event a manifest disparity in convenience of proof and opportunity for knowledge, as, for instance, where a general prohibition is applicable to every one who is unable to bring himself within the range of an exception. Greenleaf, Evidence, Vol. 1, § 79.” Id., at 90-91.
The Court added that, of course, the possible situations were too variable and that too much depended on distinctions of degree to crowd them all into a simple formula. A sharper definition was to await specific cases. Of course, if the Morrison cases are understood as approving shifting to the defendant the burden of disproving a fact necessary to constitute the crime, the result in the first Morrison case could not coexist with In re Winship, 397 U. S.(358 (1970), and Mullaney.
The State of New York is not alone in this result:
“Since the Model Penal Code was completed in 1962, some 22 states have codified and reformed their criminal laws. At least 12 of these jurisdictions have used the concept of an ‘affirmative defense’ and have defined that phrase to require that the defendant prove the existence of an ‘affirmative defense’ by a preponderance of the evidence. Additionally, at least six proposed state codes and each of the four successive versions of a revised federal code use the same procedural device. Finally, many jurisdictions that do not generally employ this concept of 'affirmative defense’ nevertheless shift the burden of proof to the defendant on particular issues.” Low & Jeffries, DICTA: Constitutionalizing the Criminal Law?, 29 Ya. Law Weekly, No. 18, p. 1 (1977) (footnotes omitted).
Even so, the trend over the years appears to have been to require the prosecution to disprove affirmative defenses beyond a reasonable doubt. See W. LaFave & A. Scott, Criminal Law § 8, p. 50 (1972); C. McCormick, Evidence § 341, pp. 800-802 (2d ed. 1972). The split among the various jurisdictions varies for any given defense. Thus, 22 jurisdictions place the burden of proving the affirmative defense of insanity on the defendant, while 28 jurisdictions place the burden of disproving insanity on the prosecution. Note, Constitutional Limitations on Allocating the Burden of Proof of Insanity to the Defendant in Murder Cases, 56 B. U. L. Rev. 499, 503-505 (1976).
The drafters of the Model Penal Code would, as a matter of policy, place the burden of proving the nonexistence of most affirmative defenses, including the defense involved in this case, on the prosecution once the defendant has come forward with some evidence that the defense is present. The drafters recognize the need for flexibility, however, and would, in “some exceptional situations,” place the burden of persuasion on the accused.
“Characteristically these are situations where the defense does not obtain at all under existing law and the Code seeks to introduce a mitigation. Resistance to the mitigation, based upon the prosecution’s difficulty in obtaining evidence, ought to be lowered if the burden of persuasion is imposed on the defendant. Where that difficulty appears genuine and there is something to be said against allowing the defense at all, we consider it defensible to shift the burden in this way.” ALI, Model Penal Code § 1.13, Comment, p. 113 (Tent. Draft No. 4,1955).
Other writers have recognized the need for flexibility in allocating the burden of proof in order to enhance the potential for liberal legislative reforms. See, e. g., Low & Jeffries, supra, n. 10; Christie & Pye, Presumptions and Assumptions in the Criminal Law: Another View, 1970 Duke L. J. 919, 933-938. See also Allen, Mullaney v. Wilbur, the Supreme Court, and the Substantive Criminal Law — An Examination of the Limits of Legitimate Intervention, 55 Texas L. Rev. 269 (1977).
Whenever due process guarantees are dependent upon the law as defined by the legislative branches, some consideration must be given to the possibility that legislative discretion may be abused to the detriment of the individual. See Mullaney v. Wilbur, 421 U. S., at 698-699. The applicability of the reasonable-doubt standard, however, has always been dependent on how a State defines the offense that is charged in any given case; yet there has been no great rush by the States to shift the burden of disproving traditional elements of the criminal offenses to the accused.
As Chief Judge Breitel cogently stated in concurring in the judgment and opinion below:
"A preliminary caveat is indicated. It would be an abuse of affirmative defenses, as it would be of presumptions in the criminal law, if the purpose or effect were to unhinge the procedural presumption of innocence which historically and constitutionally shields one charged with crime. Indeed, a by-product of such abuse might well be also to undermine the privilege against self-incrimination by in effect forcing a defendant in a criminal action to testify in his own behalf.
“Nevertheless, although one should guard against such abuses, it may be misguided, out of excess caution, to forestall or discourage the use of affirmative defenses, where defendant may have the burden of proof but no greater than by a preponderance of the evidence. In the absence of affirmative defenses the impulse to legislators, especially in periods of concern about the rise of crime, would be to define particular crimes in unqualifiedly general terms, and leave only to sentence the adjustment between offenses of lesser and greater degree. In times when there is also a retrogressive impulse in legislation to restrain courts by mandatory sentences, the evil would be compounded.
“The affirmative defense, intelligently used, permits the gradation of offenses at the earlier stages of prosecution and certainly at the trial, and thus offers the opportunity to a defendant to allege or prove, if he can, the distinction between the offense charged and the mitigating .circumstances which should ameliorate the degree or kind of offense. The instant homicide case is a good example. Absent the affirmative defense, the crime of murder or manslaughter could legislatively be defined simply to require an intent to kill, unaffected by the spontaneity with which that intent is formed or the provocative or mitigating circumstances which should legally or morally lower the grade of crime. The placing of the burden of proof on the defense, with a lower threshold, however, is fair because of defendant’s knowledge or access to the evidence other than his own on the issue. To require the prosecution to negative the ‘element’ of mitigating circumstances is generally unfair, especially since the conclusion that the negative of the circumstances is necessarily a product of definitional and therefore circular reasoning, and is easily avoided by the likely legislative practice mentioned earlier.
“In sum, the appropriate use of affirmative defenses enlarges the ameliorative aspects of a statutory scheme for the punishment of crime, rather than the other way around — a shift from primitive mechanical classifications based on the bare antisocial act and its consequences, rather than on the nature of the offender and the conditions which produce some degree of excuse for his conduct, the mark of an advanced criminology.” 39 N. Y. 2d 288, 305-307, 347 N. E. 2d 898, 909-910 (1976).
The defendant in Mullaney was convicted under Me. Rev. Stat. Ann., Tit. 17, §2651 (1964), which provided:
“Whoever unlawfully kills a human being with malice aforethought, either express or implied, is guilty of murder and shall be punished by imprisonment for life.”
There is some language in Mullaney that has been understood as perhaps construing the Due Process Clause to require the prosecution to prove beyond a reasonable doubt any fact affecting “the degree of criminal culpability.” See, e. g., Note, Affirmative Defenses After Mullaney v. Wilbur: New York’s Extreme Emotional Disturbance, 43 Brooklyn L. Rev. 171 (1976); Note, Affirmative Defenses in Ohio After Mullaney v. Wilbur, 36 Ohio St. L. J. 828 (1975); Comment, Unburdening the Criminal Defendant: Mullaney v. Wilbur and the Reasonable Doubt Standard, 11 Harv. Civ. Rights-Civ. Lib. L. Rev. 390 (1976). It is said that such a rule would deprive legislatures of any discretion whatsoever in allocating the burden of proof, the practical effect of which might be to undermine legislative reform of our criminal justice system. See Part II, supra; Low & Jeffries, supra, n. 10. Carried to its logical extreme, such a reading of Mullaney might also, for example, discourage Congress from enacting pending legislation to change the felony-murder rule by permitting the accused to prove by a preponderance of the evidence the affirmative defense that the homicide committed was neither a necessary nor a reasonably foreseeable consequence of the underlying felony. See Senate bill S. 1, 94th Cong., 1st Sess., 118 (1975). The Court did not intend Mullaney to have such far-reaching effect.