Facts of Case
At issue in this criminal case is whether the defendant was unconstitutionally assigned the burden of proving his insanity when he was tried and convicted of murder in the first degree.
Jeremy Box confessed that on the morning of May 27, 1984, he strangled Vesta Badeau and cut off her head with a butcher knife. In his recorded confession, the validity of which has not been questioned, he admitted that he had "premeditated it. . . throughout just about the entire . . . night."
On June 6, 1984, he was charged by a second amended information with murder in the first degree, while armed with a deadly weapon. He entered a plea of not guilty by reason of insanity.
A jury trial was held in Superior Court for King County. Defense counsel proposed jury instructions that would have given the State the burden of proving the defendant's sanity beyond a reasonable doubt. The trial court declined to give these instructions and instead instructed the jury that the defendant had the burden of proving his insanity by a preponderance of the evidence.
The jury returned a verdict of guilty as charged. The trial court subsequently sentenced the defendant to life imprisonment. The Court of Appeals affirmed the conviction in an unpublished opinion. We granted discretionary review.1
One issue is presented.
Issue
Was it unconstitutional to require the defendant to prove *322his claim of insanity?
Decision
Conclusion. Insanity, by force of statute, is an affirmative defense in the State of Washington which must be raised by the defendant and proved by the defendant by a preponderance of the evidence. The legislative directives to this effect do not offend either state or federal due process guaranties.
By statute in this state, insanity is a defense that the defendant has the burden of establishing by a preponderance of the evidence.2 In Washington, a defendant is required to satisfy the M'Naghten rule to prove that he is legally insane, i.e., the defendant must prove that at the time of the offense he or she was unable to perceive the nature and quality of the act charged or was unable to tell right from wrong with regard to that act.3 More than half the states in the nation join Washington in requiring a defendant to prove a claim of insanity by a preponderance of the evidence.4 The defendant argues, however, that this requirement violates both federal and state due process guaranties, and that the State should be required to bear the burden of proving a defendant's sanity when a claim of insanity is raised.
The burden which the defendant here seeks to transfer is the burden of persuasion. All courts require a defendant to bear the initial burden of producing some evidence of insanity, since the law presumes that defendants are sane at the time an alleged offense is committed.5 The disagree*323ment arises, however, over who must bear the burden of persuasion, or the burden of convincing the jury to accept their version of the facts.6
First, we consider those jurisdictions that place the persuasion burden on the prosecution when insanity is at issue. Those jurisdictions argue that the two basic elements of a crime are a criminal act (actus reus) and a criminal intent (mens rea).7 The issue of criminal responsibility focuses on the defendant's capacity to have the requisite criminal intent, or mens rea.8 Society presumes the innocence of the accused and imposes on the prosecution the burden of proving the defendant's guilt beyond a reasonable doubt. Because guilt cannot be proven without proof of the defendant's mental capacity to commit the crime, such jurisdictions reason, the prosecution should bear the burden of proving the defendant's sanity. They consider that if the burden of proving insanity is placed on the accused, the accused will be forced to disprove an essential element of the crime (sanity), and they reason that this is no more appropriate than requiring a defendant to disprove commission of a criminal act.9 In short, jurisdictions that place the burden of persuasion on the prosecution view sanity as an element required to formulate the mental state necessary for criminal behavior; hence, they require the State to prove it.10
Next we examine the other jurisdictions which, like Washington, place the burden on the defendant. These jurisdictions do not perceive a necessary relationship *324between sanity and actus reus and mens rea.11 Such jurisdictions differentiate the presence of mens rea from the capacity for responsible behavior, and perceive the issue of criminal irresponsibility as an affirmative defense to be proved by the defendant rather than as an element of the crime to be proved by the prosecution.12 In these jurisdictions, the presumption of innocence that justifies placing the burden of persuasion on the prosecution is considered offset hy the presumption of sanity.13
In the federal system, recent legislation transferred the burden of persuasion from the prosecution to the defendant, who is now required to prove his or her insanity by clear and convincing evidence.14 Cases interpreting the new federal legislation establish that placing the burden of proving insanity upon the defendant does not violate federal constitutional law.15 In a series of cases, the United States Supreme Court has indicated that the allocation of the burden of proof as to insanity is not an issue of constitutional magnitude.
In 1952, the United States Supreme Court upheld an Oregon statute, since repealed, that required the accused to establish his insanity "beyond a reasonable doubt".16 That case was Leland v. Oregon, 343 U.S. 790, 96 L. Ed. 1302, 72 S. Ct. 1002 (1952), wherein the Court held that due process does not guarantee any particular allocation of the persuasion burden.17 This holding was questioned by some after the Court subsequently held in In re Winship, 397 U.S. *325358, 364, 25 L. Ed. 2d 368, 90 S. Ct. 1068 (1970),18 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 Mullaney v. Wilbur, 421 U.S. 684, 705, 44 L. Ed. 2d 508, 95 S. Ct. 1881 (1975) (Rehnquist, J., concurring), however, Justice Rehnquist wrote that he saw no conflict between Leland and Winship.
In Mullaney, the Court held that a Maine statute requiring a murder defendant to prove that he acted in the heat of passion violated the Winship due process requirement that the prosecution must prove every fact necessary to constitute the crime charged.19 Justice Rehnquist wrote separately to show that the Court's opinion did not threaten the earlier holding in Leland. He stated that although evidence relevant to insanity may also be relevant to whether the required mens rea was present, the existence or nonexistence of legal insanity bears no necessary relationship to the existence or nonexistence of the required mental elements of the crime. As he wrote, " [f]or this reason, Oregon's placement of the burden of proof of insanity on Leland . . . did not effect an unconstitutional shift in the State's traditional burden of proof beyond a reasonable doubt of all necessary elements of the offense."20 A majority of the Court evidently agreed with Justice Rehnquist, since in Rivera v. Delaware, 429 U.S. 877, 50 L. Ed. 2d 160, 97 S. Ct. 226 (1976), the Court thereafter dismissed, as not presenting a substantial federal question, an appeal claiming that a state statute was unconstitutional because it required the defendant to prove insanity by a preponderance of the evidence.
The United States Supreme Court expressly declined to *326reconsider Leland and Rivera in Patterson v. New York, 432 U.S. 197, 53 L. Ed. 2d 281, 97 S. Ct. 2319 (1977). At issue in Patterson was the validity of a New York law requiring the defendant in a second degree murder prosecution to prove the affirmative defense of extreme emotional disturbance in order to reduce the crime to manslaughter. The Court upheld that law, holding that the defense did not negate any facts of the crime that the State had to prove to convict, but was a separate issue on which the defendant carried the burden of persuasion.21 The Court stated that 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.
[O]nce 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.
Patterson, at 206. The Patterson opinion added that proof of the nonexistence of all affirmative defenses has never been constitutionally required.22 In Jones v. United States, 463 U.S. 354, 368 n.17, 77 L. Ed. 2d 694, 103 S. Ct. 3043 (1983), the Court again cited Leland with approval.
It is thus apparent that under current federal law, the fact of insanity does not negate, and is not even directly related to, the element of mens rea or intent. Accordingly, sanity does not become an element of a crime and federal due process guaranties requiring the prosecution to prove all facts constituting a crime are not offended when a defendant is given the burden of proving his or her claim of insanity.
The defendant and amicus curiae argue, however, that a different result is required under Washington case law and *327state constitutional due process guaranties. They argue specifically that the burden of proving sanity should be borne by the State given the analysis and result of this court's opinions in State v. McCullum, 98 Wn.2d 484, 656 P.2d 1064 (1983) and State v. Acosta, 101 Wn.2d 612, 683 P.2d 1069 (1984).
In McCullum, this court held that in a first degree murder prosecution, the State must prove the absence of self-defense beyond a reasonable doubt.23 Then in Acosta, this court also held that the State bears the same burden when self-defense is raised in a prosecution for second degree assault.24
Both opinions initially cited Winship in noting that due process requires the prosecution to prove beyond a reasonable doubt every fact necessary to constitute the crime charged.25 The McCullum court then observed that the State bears the burden of proving beyond a reasonable doubt the absence of a defense if that absence is an ingredient of the offense and there is some evidence of the defense.26 Whether the absence of a defense is an ingredient of the offense is determined in one of two ways: (1) the statute may reflect a legislative intent to allocate the burden of proof to the State, or (2) one or more elements of the defense may negate one or more elements of the offense which the prosecution must prove beyond a reasonable doubt.27
In considering part one of this test, both McCullum and Acosta commented on the new criminal code's silence con*328cerning the burden of proof as to self-defense.28 These opinions then observed, however, that the Legislature had clearly provided that a defendant must prove certain defenses by a preponderance of the evidence, and specifically pointed to insanity as one such defense.29 The Acosta court concluded that "[t]he Legislature's silence on the burden of proof of self-defense, in contrast to its specificity on these other defenses, is a strong indication that the Legislature did not intend to require a defendant to prove self-defense. 30
Here we are presented with clear-cut proof that the Legislature did intend to require a defendant to prove his or her claim of insanity. RCW 10.77.030(2), which allocates the insanity burden of proof to defendants, codifies the common law rule in existence in this state from territorial days.31 Thus, in this case we are presented with a demonstrated legislative intent not to treat the absence of insanity as an ingredient of first degree murder. Indeed, this court has underscored that intent by flatly declaring that sanity is not an element of a criminal offense.32
Turning to part two of the McCullum test, the court there concluded that self-defense negates the element of intent, which is an element that the State must prove in a first degree murder case.33 The court in Acosta similarly concluded that proof of self-defense negates the knowledge element of second degree assault.34
Self-defense has been held to negate the mens rea of first *329degree murder because self-defense is defined as a lawful act,35 and the crime of first degree murder requires "intent", which is defined as acting "with the objective or purpose to accomplish a result which constitutes a crime."36 The requirement of intent is thus held to be inconsistent with a lawful act.37 Similarly, self-defense negates the mens rea of second degree assault because self-defense is defined as a lawful act, and the crime of second degree assault requires "knowledge", which is defined as being "aware of a fact, facts, or circumstances or result described by a statute defining an offense".38 The requirement of knowledge is thus likewise held to be inconsistent with the lawful act of self-defense.
By contrast, committing an act under an insane impulse does not make that act lawful. Rather, if a claim of insanity is raised, once the elements of murder are proved, the defendant's inability to distinguish right from wrong is examined in an attempt to determine his or her culpability for the murder.39 As one court recently explained it,
[IJnsanity entitles a defendant to an acquittal not because it establishes innocence (i.e., state has failed to prove element of criminal intent) but because the state declines to convict or punish one shown to have committed the crime while mentally impaired. ... In other words, the mental state of "insanity" does not go to the elements of the crime but merely the ultimate culpability of the accused.
(Citations omitted.) Gilcrist v. Kincheloe, 589 F. Supp. 291, 294 (E.D. Wash. 1984), aff'd, 774 F.2d 1173 (9th Cir. 1985).
*330The defendant in this case also argues that the defense of insanity negates the element of premeditation as well as the intent required to prove first degree murder. We recently reiterated that premeditation is the mental process of thinking beforehand, deliberation, reflection, weighing or reasoning for a period of time, however short.40 The defendant cites no case law for his contention that an insane person cannot premeditate an act. We do not believe that legal insanity precludes thinking beforehand about an act, even though such thoughts may be confused or irrational.
It is, therefore, our conclusion that insanity does not negate any element of first degree murder. Under the second part of the McCullum and Acosta test, the absence of insanity is not an element of first degree murder and need not be proven beyond a reasonable doubt by the State. We further conclude that the statute (RCW 10.77.030(2)), which requires a defendant to prove a claim of insanity by a preponderance of the evidence, offends neither federal nor state due process guaranties.
The trial court did not err in declining to give the defendant's proposed instructions pertaining to the insanity burden of proof nor did the Court of Appeals err in affirming the defendant's conviction of murder in the first degree.
Affirmed.
Pearson, C.J., Brachtenbach, Dolliver, Callow, and Durham, JJ., and Schumacher, J. Pro Tern., concur.
RAP 13.4(b).
RCW 10.77.030(2).
RCW 9A.12.010; State v. Crenshaw, 98 Wn.2d 789, 793, 659 P.2d 488 (1983).
Comment, Recent Changes in Federal Law: The Federal Insanity Defense, 46 La. L. Rev. 337, 357 (1985).
R. Slovenko, The Insanity Defense in the Wake of the Hinckley Trial, 14 Rutgers L. Rev. 373, 388 (1983); see also State v. Clark, 34 Wash. 485, 496, 76 P. 98 (1904).
1 W. LaFave & A. Scott, Jr., Substantive Criminal Law § 4.5(e), at 499-501 (1986).
G. Morris, The Insanity Defense: A Blueprint for Legislative Reform 43 (1975).
G. Morris, at 43.
G. Morris, at 43.
Comment, 46 La. L. Rev. at 357; Slovenko, 14 Rutgers L. Rev. at 388.
Slovenko, 14 Rutgers L. Rev. at 388.
D. Hermann, The Insanity Defense 15 (1983); G. Morris, at 43.
G. Morris, at 43.
18 U.S.C. § 17.
Comment, 46 La. L. Rev. at 355.
Leland v. Oregon, 343 U.S. 790, 96 L. Ed. 1302, 72 S. Ct. 1002 (1952).
Leland, at 799.
See G. Morris, at 44.
Mullaney v. Wilbur, 421 U.S. 684, 704, 44 L. Ed. 2d 508, 95 S. Ct. 1881 (1975) (Rehnquist, J., concurring).
Mullaney, at 706 (Rehnquist, J., concurring).
Patterson v. New York, 432 U.S. 197, 206-07, 53 L. Ed. 2d 281, 97 S. Ct. 2319 (1977).
Patterson, at 210.
State v. McCullum, 98 Wn.2d 484, 496, 656 P.2d 1064 (1983).
State v. Acosta, 101 Wn.2d 612, 616, 683 P.2d 1069 (1984).
McCullum, at 489; Acosta, at 615.
McCullum, at 490.
See McCullum, at 490; Acosta, at 615.
McCullum, at 492; Acosta, at 615.
McCullum, at 492; Acosta, at 615.
Acosta, at 615-16.
State v. McDonald, 89 Wn.2d 256, 271, 571 P.2d 930 (1977).
See McDonald, at 271.
McCullum, at 495.
Acosta, at 616.
RCW 9A.16.020(3).
RCW 9A.08.010(l)(a); State v. Russell, 47 Wn. App. 848, 851, 737 P.2d 698 (1987).
See Russell, at 851; State v. Peters, 47 Wn. App. 854, 859, 737 P.2d 693 (1987).
RCW 9A.08.010(l)(b)(i); Russell, at 851.
See D. Hermann, at 127.
State v. Bingham, 105 Wn.2d 820, 823, 719 P.2d 109 (1986).