concurring:
I join the majority in concluding as a general proposition that the “three strikes” law does not constitute double jeopardy, infringe on the separation of powers, violate the Ex Post Facto Clause, inflict a cruel or unusual punishment, or deny the effective assistance of counsel. I further agree that the statute requires courts to employ a fact-specific, case-by-case approach in determining whether prior convictions for unenumerated offenses constitute “strikes.”
I also concur that 18 U.S.C. § 3559(c)(3)(A) does not comport with the requirements of due process.1 However, I reach this conclusion for a different reason. Although I agree with the majority’s analysis, I find it unnecessary to reach the question of whether the use or threatened use of a firearm constitutes an element rather than an exception. In my view, the “clear and convincing” burden of proof, even if it were applied to a true exception, violates due process. I would therefore hold the statute unconstitutional on a narrower basis.
A sentencing process, like a criminal trial, must satisfy the requirements of due process. Gardner v. Florida, 430 U.S. 349, 358, 97 S.Ct. 1197, 51 L.Ed.2d 393 (1977). In the context of sentence enhancements, due process typically requires that the government prove enhancing factors by a preponderance of the evidence. McMillan v. Pennsylvania, 477 U.S. 79, 91, 106 S.Ct. 2411, 91 L.Ed.2d 67 (1986); United States v. Restrepo, 946 F.2d 654, 658-59 (9th Cir.1991). Moreover, the “preponderance” standard is not constitutionally adequate in all sentencing cases. Rather, a higher standard of proof is required where the factor to be proved would have “an extremely disproportionate effect on the sentence relative to the offense of conviction.” United States v. Restrepo, 946 F.2d at 659. See also Witte v. United States, 515 U.S. 389, 403, 115 S.Ct. 2199, 132 L.Ed.2d 351 (1995); United States v. Townley, 929 F.2d 365, 370 (8th Cir.1991).
A long-standing rule of statutory construction, also establishes that the burden of production and proof may, under narrowly circumscribed conditions, be shifted to a defendant in a criminal case. Where a defendant seeks to rely on an exception to a criminal statute, he generally bears the burden of establishing and showing that he comes within that exception. See United States v. Gravenmeir, 121 F.3d 526, 528 (9th Cir.1997); United States v. Freter, 31 F.3d 783, 788 (9th Cir.1994); Walker v. Endell, 850 F.2d 470, 473 (9th Cir.1987). However, none of the “statutory exception” cases impose a “clear and convincing” burden of proof on the defendant. Indeed, in some circumstances, the burden of proof may not be shifted to the defendant at all. See Gravenmeir, 121 F.3d at 528 (noting that the burden ought not to be shifted to the defendant when it is “overbearing”).
“The function of a standard of proof, as that concept is embodied in the Due Process Clause and in the realm of factfinding, is to instruct the factfinder concerning the degree of confidence our society thinks he should have in the correctness of factual conclusions for a particular type of adjudication.” Addington v. Texas, 441 U.S. 418, 423, 99 S.Ct. 1804, 60 L.Ed.2d 323 (1979) (citations and internal quotation marks omitted). As the government increases a defendant’s burden of proof, that defendant concomitantly shoulders an ever-increasing risk of an erroneous decision. Id. At some point, placing a particular burden of proof on a criminal defendant violates the Due Process Clause. The ques*1085tion presented by this ease is whether, in placing a “clear and convincing” burden of proof on defendants who seek to invoke section 3559(c)(3), Congress has reached that juncture.
The Supreme Court articulated the general due process principles by which burdens of proof should be examined in Cooper v. Oklahoma, 517 U.S. 348, 116 S.Ct. 1373, 134 L.Ed.2d 498 (1996) and McMillan v. Pennsylvania, 477 U.S. 79, 106 S.Ct. 2411, 91 L.Ed.2d 67 (1986). In Cooper, the Court struck down an Oklahoma statute creating a presumption that a criminal defendant was competent to stand trial unless he proved his incompetence by clear and convincing evidence. Id. 116 S.Ct. at 1383. In that case, two state-employed psychologists had offered conflicting opinions regarding the defendant’s competence. Id. at 1375. Although the trial judge noted that the question was a close one, he ultimately concluded that the defendant had not carried his burden by “clear and convincing” evidence and would therefore be tried. Id. at 1376.
In holding the statute unconstitutional, the Supreme Court rejected the notion that a state could “proceed with a criminal trial after a defendant has shown that he is more likely than not incompetent.” Id. at 1374. The Court’s analysis focused on two main inquiries: (1) whether the historical and contemporary practices of most jurisdictions was to impose this heightened standard of proof in incompetency determinations, thus suggesting both that it was necessary to “vindicate the State’s interest in prompt and orderly disposition of criminal cases,” and that it did not offend “a principle of justice that is deeply rooted in the traditions and conscience of our people;” and (2) whether an evaluation of the risks inherent in requiring a clear and convincing standard of proof led to the conclusion that the practice was consistent with due process. Id. at 1380-81 (citations and internal quotation marks omitted).
Addressing the first question, the Court noted that almost all other jurisdictions applied a standard that was more protective of a defendant’s rights than was Oklahoma’s “clear and convincing” rule, providing evidence that the rule did, in fact, violate a deeply-rooted principle of justice. Id. at 1380.
Turning to the second question, the Court noted both that the risk of error was very high, and that the consequences of error for the defendant were dire. The risk of error was high because, unlike using a preponderance standard, which would affect only a narrow class of cases in which the evidence on either side was equally balanced, the use of a clear and convincing standard would affect a class of cases in which the defendant had demonstrated that, more likely than not, he was incompetent. Id. at 1381. The consequences of error would be dire because, if Cooper were erroneously determined to be competent, his inability to assist in his own defense would result in a denial of a fair trial. Id. By contrast, the Court noted, the “injury to the State of the opposite error-a conclusion that the defendant is incompetent when he is in fact malingering-is modest.” Id. at 1382.
Ultimately, the Court concluded that, in the context of a competency determination, the Due Process Clause would not permit a state to allocate to a criminal defendant “the large share of the risk which accompanies a clear and convincing evidence standard.” Id. at 1383-84.
In McMillan v. Pennsylvania, 477 U.S. 79, 106 S.Ct. 2411, 91 L.Ed.2d 67 (1986), the Supreme Court upheld Pennsylvania’s Mandatory Minimum Sentencing Act. The Act provided that anyone convicted of certain enumerated felonies was subject to a mandatory minimum of five years’ imprisonment if the sentencing judge found by a preponderance of the evidence that the person visibly possessed a firearm during the commission of the offense. The Court rejected the theory that the State had to prove-visible possession of a firearm beyond a reasonable doubt. Id. at 84, 106 S.Ct. 2411. In reaching this conclusion, the Court discussed the balance of interests present in a sentencing proceeding. Id. at 83-84, 106 S.Ct. 2411. On the one hand was the government’s interest in deterring the illegal use of firearms; on the other was the defendant’s liberty interest, which had been diminished by a guilty verdict. The risk at stake for both parties was the risk of error: that the Court would be mistaken in its determination that a firearm was *1086or was not visible during the commission of the crime.
Weighing the interests and the risks at stake, the Court affirmed the lower Court’s determination that, on balance, “it is reasonable for the defendant and the Commonwealth to share equally in any risk of error.” Id. The Court declined to establish a bright line rule, noting that the constitutionality of similar statutes would “depend on differences of degree,” and that “the law is full of situations in which differences of degree produce different results.” Id. at 91, 106 S.Ct. 2411.
Consistent with McMillan, the Court recently held in United States v. Watts, 519 U.S. 148, 117 S.Ct. 683, 136 L.Ed.2d 554 (1997), that an acquittal in a criminal case did not preclude the sentencing judge from enhancing a sentence based on the facts underlying the alleged crime. Watts reaffirmed that the “preponderance standard at sentencing generally satisfies due process” but noted that there was a divergence among the circuits as to whether “relevant conduct that would dramatically increase the sentence must be based on clear and convincing evidence.” Id. 117 S.Ct. at 637.
The statute at hand, 18 U.S.C. §.3559, turns these principles on their head. It places a negligible burden of proof on the prosecution, but forces the defendant to shoulder one of the highest burdens extant in the law: proof by clear and convincing evidence. Thus, rather than embracing the notion of “shared risk” as articulated in Cooper and McMillan, the statute imposes a Sisyphean evidentiary weight on the defendant. The effect on this case is not trivial. Indeed, the standard of proof employed is probably determinative of whether Kaluna will spend the rest of his life in prison.
Such a scheme cannot pass constitutional muster. First, no court has held that a defendant may, consistent with due process, assume a clear and convincing standard of proof as to matters which “dramatically increase the sentence.” Watts, 117 S.Ct. at 637. In fact, the salient question in sentencing cases has been not whether the defendant, but rather whether the prosecution should be held to a higher burden of proof. See, e.g., McMillan, 477 U.S. at 88, 106 S.Ct. 2411; Restrepo, 946 F.2d at 659; United States v. Lombard, 72 F.3d 170, 175 n. 6, 177-80 (1st Cir.1995); Witte, 515 U.S. at 403, 115 S.Ct. 2199; Townley, 929 F.2d at 370; United States v. Trujillo, 959 F.2d 1377, 1382 (7th Cir.1992); United States v. Kikumura, 918 F.2d 1084, 1100 (3d Cir.1990).
Moreover, where, as here, an enhancement provision results in a great disparity between the sentence for the crime charged in the indictment and the sentence imposed, courts have placed a higher burden on the prosecution. As the Third Circuit has noted, “[i]n this extreme context, ... a court cannot reflexively apply the truncated procedures that are perfectly adequate for all of the more mundane, familiar, sentencing determinations.” Kikumura, 918 F.2d at 1100. Thus, precedent suggests that the prosecution ought to bear a higher burden of proof in cases such as the one at bar; no court has ever sustained a burden-shift requiring “clear and convincing” evidence from the defendant under similar circumstances.
Second, the statute creates a grave risk of error. The “more stringent the burden of proof a party must bear, the more that party bears the risk of an erroneous decision.” Cooper, 116 S.Ct. at 1381 (quoting Cruzan v. Director, Mo. Dept. of Health, 497 U.S. 261, 283, 110 S.Ct. 2841, 111 L.Ed.2d 224 (1990)). Because the sentence enhancement is founded on historical events, the probability of an erroneous decision under section 3559(c)(3)(A) is substantially higher than the corresponding risks' in either Cooper or McMillan. In Cooper, 116 S.Ct. at 1374-75, the issue was the defendant’s present competency, one which could be assessed from the evidence at hand. In McMillan, 477 U.S. at 84, 106 S.Ct. 2411, the sentencing factor was visible possession of a firearm in the commission of the charged crime, again a fact which could be readily ascertained within the ease context. Id. at 84, 106 S.Ct. 2411.
Here, by contrast, the prosecution seeks to use a 1975 conviction, for the second degree robbery of Bill’s Bakery in Honolulu, Hawaii, as Kaluna’s “third strike.” In order to avoid a life sentence, Kaluna must assemble clear and convincing proof that he did not use, or threaten to use, a firearm or another dangerous weapon in a crime to which he pled guilty *1087over twenty years ago. That task would be formidable under a mere preponderance standard; it becomes an near-futile exercise under the constraint of producing “clear and convincing” proof.
The district court in this case relied solely on the indictment charging Kaluna with first degree robbery, and accepted as true the facts alleged therein. Kaluna, in fact, pled guilty to second degree robbery, a lesser crime which does not include the use of a weapon as an element of the offense. The plea does not contain any reference to the use or threat of use of a weapon. The uncertainties inherent in relying on a decades old, ambiguous record underscore the substantial risk of the court making an erroneous determination based solely on the high burden of proof imposed on the defendant.2
Finally, the consequences of an erroneous determination are severe. Even if Kaluna were able to show that, more likely than not, he did not use or threaten to use a firearm or other dangerous weapon in the Bill’s Bakery robbery, application of the statute would mandate life imprisonment. The district court imposed a life sentence on Kaluna based entirely on the standard of proof, specifically finding that Kaluna had failed to meet his burden “to preclude the use of any of his convictions.” Thus, the similarities with Cooper are obvious: for Kaluna and those in like situations, the risk of error is high, and the consequences dire.
Thus, notwithstanding the less stringent constitutional standards which govern sentencing, see Restrepo, 946 F.2d at 658-59, 18 U.S.C. § 3559 violates due process. Congress may not, as it has sought to do here, “advance the objectives of its criminal laws at the expense of the accurate factfinding owed to the criminally accused who suffer the risk of nonpersuasion.” McMillan, 477 U.S. at 102, 106 S.Ct. 2411 (Stevens, J., dissenting). Rather, the values underlying procedural due process — particularly those of accuracy and the appearance of fairness — require a more equal distribution of the risk than is contemplated by this statute.
Because 18 U.S.C. § 3559(c)(3)(A) as applied to Kaluna violates due process, we need not decide whether the factor to be disproved constitutes a true exception. Thus, although I agree with the majority’s conclusion, I would not reach the broader issue of whether the statutory burden-shifting is itself impermissible. Instead, I would hold the statute unconstitutional because the burden it places on the defendant of disproving a sentence enhancement factor by “clear and convincing” evidence violates due process.
. I therefore agree that sections 3(A), 2(F)(ii), and the robbery clause of (2)(F)(i) are invalid and must be severed from the statute.
. The dissent contends that "Kaluna never tried to prove nor does he even suggest that he did not use a firearm or other weapon in his robbery of Bill’s Bakery.” Although Kaluna did not testify at the sentencing hearing, his counsel argued that the Bill’s Bakery robbery did not qualify under the statute because Kaluna’s plea did not reference use or threat of use of a weapon, and the offense to which Kaluna pled did not contain a weapons element. Thus, Kaluna did contest inclusion of the offense, albeit on the basis of the record, not with personal testimony.