Justice Kennedy
delivered the opinion of the Court.
It is well established that the Due Process Clause of the Fourteenth Amendment prohibits the criminal prosecution of a defendant who is not competent to stand trial. Drope v. Missouri, 420 U. S. 162 (1975); Pate v. Robinson, 383 U. S. 375 (1966). The issue in this case is whether the Due Process Clause permits a State to require a defendant who alleges incompetence to stand trial to bear the burden of proving so by a preponderance of the evidence.
In 1984, petitioner Teofilo Medina, dr., stole a gun from a pawnshop in Santa Ana, California. In the weeks that followed, he held up two gas stations, a drive-in dairy, and a market, murdered three employees of those establishments, attempted to rob a fourth employee, and shot at two passersby who attempted to follow his getaway car. Petitioner was apprehended less than one month after his crime spree began and was charged with a number of criminal offenses, including three counts of first-degree murder. Before trial, petitioner’s counsel moved for a competency hearing under Cal. Penal Code Ann. § 1368 (West 1982), on the ground that he was unsure whether petitioner had the ability to participate in the criminal proceedings against him. 1 Record 320.
Under California law, “[a] person cannot be tried or adjudged to punishment while such person is mentally incompetent.” Cal. Penal Code Ann. §1367 (West 1982). A defendant is mentally incompetent “if, as a result of mental disorder or developmental disability, the defendant is unable to understand the nature of the criminal proceedings or to assist counsel in the conduct of a defense in a rational manner.” Ibid. The statute establishes a presumption that the defendant is competent, and the party claiming incompetence bears the burden of proving that the defendant is incompetent by a preponderance of the evidence. § 1369(f) (“It shall be presumed that the defendant is mentally competent unless it is proved by a preponderance of the evidence that the defendant is mentally incompetent”).
The trial court granted the motion for a hearing and the preliminary issue of petitioner’s competence to stand trial was tried to a jury. Over the course of the 6-day hearing, in addition to lay testimony, the jury heard conflicting expert testimony about petitioner’s mental condition. The Supreme Court of California gives this summary:
“Dr. Gold, a psychiatrist who knew defendant while he was in the Arizona prison system, testified that defendant was a paranoid schizophrenic and was incompetent to assist his attorney at trial. Dr. Echeandia, a clinical psychologist at the Orange County jail, doubted the accuracy of the schizophrenia diagnosis, and could not express an opinion on defendant’s competence to stand trial. Dr. Sharma, a psychiatrist, likewise expressed doubts regarding the schizophrenia diagnosis and leaned toward a finding of competence. Dr. Pierce, a psychologist, believed defendant was schizophrenic, with impaired memory and hallucinations, but nevertheless was competent to stand trial. Dr. Sakurai, a jail psychiatrist, opined that although defendant suffered from depression, he was competent, and that he may have been malingering. Dr. Sheffield, who treated defendant for knife wounds he incurred in jail, could give no opinion on the competency issue.” 51 Cal. 3d 870, 880, 799 P. 2d 1282, 1288 (1990).
During the competency hearing, petitioner engaged in several verbal and physical outbursts. App. 62, 81-82; 3 Record 671, 699, 916. On one of these occasions, he overturned the counsel table. App. 81-82.
The trial court instructed the jury in accordance with § 1369(f) that “the defendant is presumed to be mentally competent and he has the burden of proving by a preponderance of the evidence that he is mentally incompetent as a result of mental disorder or developmental disability.” App. 87. The jury found petitioner competent to stand trial. Id., at 89. A new jury was empaneled for the criminal trial, 4 Record 1020, and petitioner entered pleas of not guilty and not guilty by reason of insanity, 51 Cal. 3d, at 899, 799 R 2d, at 1300. At the conclusion of the guilt phase, petitioner was found guilty of all three counts of first-degree murder and a number of lesser offenses. Id., at 878-879, 799 P. 2d, at 1287. He moved to withdraw his insanity plea, and the trial court granted the motion. Two days later, however, petitioner moved to reinstate his insanity plea. Although his counsel expressed the view that reinstatement of the insanity plea was “tactically unsound,” the trial court granted petitioner’s motion. Id., at 899, 799 P. 2d, at 1300-1301. A sanity hearing was held, and the jury found that petitioner was sane at the time of the offenses. At the penalty phase, the jury found that the murders were premeditated and deliberate and returned a verdict of death. The trial court imposed the death penalty for the murder convictions and sentenced petitioner to a prison term for the remaining offenses. Id., at 878-880, 799 P. 2d, at 1287-1288.
On direct appeal to the California Supreme Court, petitioner did not challenge the standard of proof set forth in § 1369(f), but argued that the statute violated his right to due process by placing the burden of proof on him to establish that he was not competent to stand trial. In addition, he argued that § 1369(f) violates due process by establishing a presumption that a defendant is competent to stand trial unless proven otherwise. The court rejected both of these contentions. Relying upon our decision in Leland v. Oregon, 343 U. S. 790 (1952), which rejected a due process challenge to an Oregon statute that required a criminal defendant to prove the defense of insanity beyond a reasonable doubt, the court observed that “the states ordinarily have great latitude to deeide the proper placement of proof burdens.” 51 Cal. 3d, at 884, 799 P. 2d, at 1291. In its view, § 1369(f) “does not subject the defendant to hardship or oppression,” because “one might reasonably expect that the defendant and his counsel would have better access than the People to the facts relevant to the court’s competency inquiry.” Id., at 885, 799 P. 2d, at 1291. The court also rejected petitioner’s argument that it is “irrational” to retain a presumption of competence after sufficient doubt has arisen as to a defendant’s competence to warrant a hearing and “deeline[d] to hold as a matter of due process that such a presumption must be treated as a mere presumption affecting the burden of production, which disappears merely because a preliminary, often undefined and indefinite, ‘doubt’ has arisen that justifies further inquiry into the matter.” Id., at 885, 799 P. 2d, at 1291-1292. We granted certiorari, 502 U. S. 924 (1991), and now affirm.
II
Petitioner argues that our decision in Mathews v. Eldridge, 424 U. S. 319 (1976), provides the proper analytical framework for determining whether California’s allocation of the burden of proof in competency hearings comports with due process. We disagree. In Mathews, we articulated a three-factor test for evaluating procedural due process claims which requires a court to consider
“[fjirst, the private interest that will be affected by the official action; second, the risk of an erroneous deprivation of such interest through the procedures used, and the probable value, if any, of additional or substitute procedural safeguards; and finally, the Government’s interest, including the function involved and the fiscal and administrative burdens that the additional or substitute procedural requirement would entail.” Id., at 335.
In our view, the Mathews balancing test does not provide the appropriate framework for assessing the validity of state procedural rules which, like the one at bar, are part of the criminal process. E. g., People v. Fields, 62 Cal. 2d 538, 542, 399 P. 2d 369, 371 (competency hearing “must be regarded as part of the proceedings in the criminal case”) (internal quotation marks omitted), cert. denied, 382 U. S. 858 (1965).
In the field of criminal law, we “have defined the category of infractions that violate ‘fundamental fairness’ very narrowly” based on the recognition that, “[bjeyond the specific guarantees enumerated in the Bill of Rights, the Due Process Clause has limited operation.” Dowling v. United States, 493 U. S. 342, 352 (1990); accord, United States v. Lovasco, 431 U. S. 783, 790 (1977). The Bill of Rights speaks in explicit terms to many aspects of criminal procedure, and the expansion of those constitutional guarantees under the open-ended rubric of the Due Process Clause invites undue interference with both considered legislative judgments and the careful balance that the Constitution strikes between liberty and order. As we said in Spencer v. Texas, 385 U. S. 554, 564 (1967), “it has never been thought that [decisions under the Due Process Clause] establish this Court as a rule-making organ for the promulgation of state rules of criminal procedure.” Accord, Estelle v. McGuire, 502 U. S. 62, 70 (1991); Marshall v. Lonberger, 459 U. S. 422, 438, n. 6 (1983).
Mathews itself involved a due process challenge to the adequacy of administrative procedures established for the purpose of terminating Social Security disability benefits, and the Mathews balancing test was first conceived to address due process claims arising in the context of administrative law. Although we have since characterized, the Mathews balancing test as "a general approach for testing challenged state procedures under a due process claim,” Parham v. J. R., 442 U. S. 584, 599 (1979), and applied it in a variety of contexts, e. g., Santosky v. Kramer, 455 U. S. 745 (1982) (standard of proof for termination of parental rights over objection); Addington v. Texas, 441 U. S. 418 (1979) (standard of proof for involuntary civil commitment to mental hospital for indefinite period), we have invoked Mathews in resolving due process claims in criminal law cases on only two occasions.
In United States v. Raddatz, 447 U. S. 667 (1980), we cited to the Mathews balancing test in rejecting a due process challenge to a provision of the Federal Magistrates Act which authorized magistrates to make findings and recommendations on motions to suppress evidence. In Ake v. Oklahoma, 470 U. S. 68 (1985), we relied upon Mathews in holding that, when an indigent capital defendant has made a preliminary showing that his sanity at the time of the offense is likely to be a significant factor at trial, due process requires that the defendant be provided access to the assistance of a psychiatrist. Without disturbing the holdings of Raddatz and Ake, it is not at all clear that Mathews was essential to the results reached in those cases. In Raddatz, supra, at 677-681, the Court adverted to the Mathews balancing test, but did not explicitly rely upon it in conducting the due process analysis. Raddatz, supra, at 700 (Marshall, J., dissenting) (“The Court recites th[e] test, but it does not even attempt to apply it”). The holding in Ake can be understood as an expansion of earlier due process cases holding that an indigent criminal defendant is entitled to the minimum assistance necessary to assure him “a fair opportunity to present his defense” and “to participate meaningfully in [the] judicial proceeding.” Ake, supra, at 76.
The proper analytical approach, and the one that we adopt here, is that set forth in Patterson v. New York, 432 U. S. 197 (1977), which was decided one year after Mathews. In Patterson, we rejected a due process challenge to a New York law which placed on a criminal defendant the burden of proving the affirmative defense of extreme emotional disturbance. Bather than relying upon the Mathews balancing test, however, we reasoned that a narrower inquiry was more appropriate:
“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).” Patterson v. New York, supra, at 201-202.
Accord, Martin v. Ohio, 480 U. S. 228, 232 (1987). As Patterson suggests, because the States have considerable expertise in matters of criminal procedure and the criminal process is grounded in centuries of common-law tradition, it is appropriate to exercise substantial deference to legislative judgments in this area. The analytical approach endorsed in Patterson is thus far less intrusive than that approved in Mathews.
Based on our review of the historical treatment of the burden of proof in competency proceedings, the operation of the challenged rule, and our precedents, we cannot say that the allocation of the burden of proof to a criminal defendant to prove incompetence "offends some principle of justice so rooted in the traditions and conscience of our people as to be ranked as fundamental.” Patterson v. New York, supra, at 202 (internal quotation marks omitted). Historical practice is probative of whether a procedural rule can be characterized as fundamental. See 432 U. S., at 202; In re Winship, 397 U. S. 358, 361 (1970). The rule that a criminal defendant who is incompetent should not be required to stand trial has deep roots in our common-law heritage. Blackstone acknowledged that a defendant “who became ‘mad’ after the commission of an offense should not be arraigned for it ‘because he is not able to plead to it with that advice and caution that he ought,’” and “if he became ‘mad’ after pleading, he should not be tried, ‘for how can he make his defense?’” Drope v. Missouri, 420 U. S., at 171 (quoting 4 W. Blackstone, Commentaries *24); accord, 1 M. Hale, Pleas of the Crown *34-*35.
By contrast, there is no settled tradition on the proper allocation of the burden of proof in a proceeding to determine competence. Petitioner concedes that ‘‘[t]he common law rule on this issue at the time the Constitution was adopted is not entirely clear.” Brief for Petitioner 36. Early English authorities either express no view on the subject, e.g., Firth's Case (1790), 22 Howell St. Tr. 307,811,317-318 (1817); Kinloch’s Case (1746), 18 Howell St. Tr. 395, 411 (1813), or are ambiguous. E. g., King v. Steel, 1 Leach 452, 168 Eng. Rep. 328 (1787) (stating that, once a jury had determined that the defendant was “mute by the visitation of God” (i. e., deaf and dumb) and not “mute of malice,” there arose a “presumption of ideotism” that the prosecution could rebut by demonstrating that the defendant had the capacity “to understand by signs and tokens”).
Nineteenth century English decisions do not take a consistent position on the allocation of the burden of proof. Compare R. v. Turton, 6 Cox C. C. 385 (1854) (burden on defendant), with R. v. Davies, 3 Carrington & Kirwan 328, 175 Eng. Rep. 575 (1853) (burden on prosecution); see generally R. v. Podola, 43 Crim. App. 220, 235-236, 3 All E. R. 418, 429-430 (1959) (collecting conflicting cases). American decisions dating from the turn of the century also express divergent views on the subject. E. g., United States v. Chisolm, 149 F. 284, 290 (SD Ala. 1906) (defendant bears burden of raising a reasonable doubt as to competence); State v. Helm, 69 Ark. 167, 170-171, 61 S. W. 915, 916 (1901) (burden on defendant to prove incompetence).
Contemporary practice, while of limited relevance to the due process inquiry, see Martin v. Ohio, supra, at 236; Patterson v. New York, supra, at 211, demonstrates that there remains no settled view of where the burden of proof should lie. The Federal Government and all 50 States have adopted procedures that address the issue of a defendant’s competence to stand trial. See 18 U. S. C. §4241; S. -Brakel, J. Parry, & B. Weiner, The Mentally Disabled and the Law, Table 12.1, pp. 744-754 (3d ed. 1985). Some States have enacted statutes that, like § 1369(f), place the burden of proof on the party raising the issue. E. g., Conn. Gen. Stat. § 54-56d(b) (1991); Pa. Stat. Ann., Tit. 50, § 7403(a) (Purdon Supp. 1991). A number of state courts have said that the burden of proof may be placed on the defendant to prove incompetence. E. g., Wallace v. State, 248 Ga. 255, 258-259, 282 S. E. 2d 325, 330 (1981), cert. denied, 455 U. S. 927 (1982); State v. Aumann, 265 N. W. 2d 316, 319-320 (Iowa 1978); State v. Chapman, 104 N. M. 324, 327-328, 721 P. 2d 392, 395-396 (1986); Barber v. State, 757 S. W. 2d 359, 362-363 (Tex. Crim. App. 1988) (en banc), cert. denied, 489 U. S. 1091 (1989). Still other state courts have said that the burden rests with the prosecution. E, g., Diaz v. State, 508 A. 2d 861, 863-864 (Del. 1986); Commonwealth v. Crowley, 393 Mass. 393, 400-401, 471 N. E. 2d 353, 357-358 (1984); State v. Bertrand, 123 N. H. 719, 727-728, 465 A. 2d 912, 916 (1983); State v. Jones, 406 N. W. 2d 366, 369-370 (S. D. 1987).
Discerning no historical basis for concluding that the allocation of the burden of proving incompetence to the defendant violates due process, we turn to consider whether the rule transgresses any recognized principle of “fundamental fairness” in operation. Dowling v. United States, 493 U. S., at 352. Respondent argues that our decision in Leland v. Oregon, 343 U. S. 790 (1952), which upheld the right of the State to place on a defendant the burden of proving the defense of insanity beyond a reasonable doubt, compels the conclusion that § 1369(f) is constitutional because, like a finding of insanity, a finding of incompetence has no necessary relationship to the elements of a crime, on which the State bears the burden of proof. See also Rivera v. Delaware, 429 U. S. 877 (1976). This analogy is not convincing, because there are significant differences between a claim of incompetence and a plea of not guilty by reason of insanity. See Drope v. Missouri, supra, at 176-177; Jackson v. Indiana, 406 U. S. 715, 739 (1972).
In a competency hearing, the “emphasis is on [the defendant’s] capacity to consult with counsel and to comprehend the proceedings, and . . . this is by no means the same test as those which determine criminal responsibility at the time of the crime.” Pate v. Robinson, 383 U. S., at 388-389 (Harlan, J., dissenting). If a defendant is incompetent, due process considerations require suspension of the criminal trial until such time, if any, that the defendant regains the capacity to participate in his defense and understand the proceedings against him. See Dusky v. United States, 362 U. S. 402 (1960) (per curiam). The entry of a plea of not guilty by reason of insanity, by contrast, presupposes that the defendant is competent to stand trial and to enter a plea. Moreover, while the Due Process Clause affords an incompetent defendant the right not to be tried, Drope v. Missouri, supra, at 172-173; Pate v. Robinson, supra, at 386, we have not said that the Constitution requires the States to recognize the insanity defense. See, e.g., Powell v. Texas, 392 U. S. 514, 536-537 (1968).
Under California law, the allocation of the burden of proof to the defendant will affect competency determinations only in a narrow class of cases where the evidence is in equipoise; that is, where the evidence that a defendant is competent is just as strong as the evidence that he is incompetent. See United States v. DiGilio, 538 F. 2d 972, 988 (CA3 1976), cert. denied, 429 U. S. 1038 (1977). Our cases recognize that a defendant has a constitutional right “not to be tried while legally incompetent,” and that a State’s “failure to observe procedures adequate to protect a defendant’s right not to be tried or convicted while incompetent to stand trial deprives him of his due process right to a fair trial.” Drope v. Missouri, 420 U. S., at 172, 173. Once a State provides a defendant access to procedures for making a competency evaluation, however, we perceive no basis for holding that due process further requires the State to assume the burden of vindicating the defendant’s constitutional right by persuading the trier of fact that the defendant is competent to stand trial.
Petitioner relies upon federal- and state-court decisions which have said that the allocation of the burden of proof to the defendant in these circumstances is inconsistent with the rule of Pate v. Robinson, supra, at 384, where we held that a defendant whose competence is in doubt cannot be deemed to have waived his right to a competency hearing. E.g., United States v. DiGilio, supra, at 988; People v. McCullum, 66 Ill. 2d 306, 312-314, 362 N. E. 2d 307, 310-311 (1977); State v. Bertrand, supra, at 727-728, 465 A. 2d, at 916. Because “ ‘it is contradictory to argue that a defendant may be incompetent, and yet knowingly or intelligently “waive” his right to have the court determine his capacity to stand trial/” it has been said that it is also “contradictory to argue that a defendant who may be incompetent should be presumed to possess sufficient intelligence that he will be able to adduce evidence of his incompetency which might otherwise be within his grasp.” United States v. DiGilio, supra, at 988 (quoting Pate v. Robinson, supra, at 384).
In our view, the question whether a defendant whose competence is in doubt may waive his right to a competency hearing is quite different from the question whether the burden of proof may be placed on the defendant once a hearing is held. The rule announced in Pate was driven by our concern that it is impossible to say whether a defendant whose competence is in doubt has made a knowing and intelligent waiver of his right to a competency hearing. Once a competency hearing is held, however, the defendant is entitled to the assistance of counsel, e. g., Estelle v. Smith, 451 U. S. 454, 469-471 (1981), and psychiatric evidence is brought to bear on the question of the defendant’s mental condition, see, e. g., Cal. Penal Code Ann. §§ 1369(a), 1370 (West 1982 and Supp. 1992); see generally Brakel, Parry, & Weiner, The Mentally Disabled and the Law, at 697-698. Although an impaired defendant might be limited in his ability to assist counsel in demonstrating incompetence, the defendant’s inability to assist counsel can, in and of itself, constitute probative evidence of incompetence, and defense counsel will often have the best-informed view of the defendant’s ability to participate in his defense. E. g., United States v. David, 167 U. S. App. D. C. 117, 122, 511 F. 2d 355, 360 (1975); United States ex rel. Roth v. Zelker, 455 F. 2d 1105, 1108 (CA2), cert. denied, 408 U. S. 927 (1972). While reasonable minds may differ as to the wisdom of placing the burden of proof on the defendant in these circumstances, we believe that a State may take such factors into account in making judgments as to the allocation of the burden of proof, and we see no basis for concluding that placing the burden on the defendant violates the principle approved in Pate.
Petitioner argues that psychiatry is an inexact science, and that placing the burden of proof on the defendant violates due process because it requires the defendant to “bear the risk of being forced to stand trial as a result of an erroneous finding of competency.” Brief for Petitioner 8. Our cases recognize that “[t]he subtleties and nuances of psychiatric diagnosis render certainties virtually beyond reach in most situations,” because “[pjsychiatric diagnosis ... is to a large extent based on medical ‘impressions’ drawn from subjective analysis and filtered through the experience of the diagnostician.” Addington v. Texas, 441 U. S., at 430. The Due Process Clause does not, however, require a State to adopt one procedure over another on the basis that it may produce results more favorable to the accused. See, e. g., Patterson v. New York, 432 U. S., at 208 (“Due process does not require that every conceivable step be taken, at whatever cost, to eliminate the possibility of convicting an innocent person”); Snyder v. Massachusetts, 291 U. S. 97, 105 (1934) (a state procedure “does not run foul of the Fourteenth Amendment because another method may seem to our thinking to be fairer or wiser or to give a surer promise of protection to the prisoner at the bar”). Consistent with our precedents, it is enough that the State affords the criminal defendant on whose behalf a plea of incompetence is asserted a reasonable opportunity to demonstrate that he is not competent to stand trial.
Petitioner further contends that the burden of proof should be placed on the State because we have allocated the burden to the State on a variety of other issues that implicate a criminal defendant’s constitutional rights. E. g., Colorado v. Connelly, 479 U. S. 157, 168-169 (1986) (waiver of Miranda rights); Nix v. Williams, 467 U. S. 431, 444-445, n. 5 (1984) (inevitable discovery of evidence obtained by unlawful means); United States v. Matlock, 415 U. S. 164, 177-178, n. 14 (1974) (voluntariness of consent to search); Lego v. Twomey, 404 U. S. 477, 489 (1972) (voluntariness of confession). The decisions upon which petitioner relies, however, do not control the result here, because they involved situations where the government sought to introduce inculpatory evidence obtained by virtue of a waiver of, or in violation of, a defendant’s constitutional rights. In such circumstances, allocating the burden of proof to the government furthers the objective of “deterring lawless conduct by police and prosecution.” Ibid. No such purpose is served by allocating the burden of proof to the government in a competency hearing.
In light of our determination that the allocation of the burden of proof to the defendant does not offend due process, it is not difficult to dispose of petitioner’s challenge to the presumption of competence imposed by § 1369(f). Under California law, a defendant is required to make a threshold showing of incompetence before a hearing is required and, at the hearing, the defendant may be prevented from making decisions that are normally left to the discretion of a competent defendant. E. g., People v. Samuel, 29 Cal. 3d 489, 495-496, 629 P. 2d 485, 486-487 (1981). Petitioner argues that, once the trial court has expressed a doubt as to the defendant’s competence, a hearing is held, and the defendant is deprived of his right to make determinations reserved to competent persons, it is irrational to retain the presumption that the defendant is competent.
In rejecting this contention below, the California Supreme Court observed that “[t]he primary significance of the presumption of competence is to place on defendant (or the People, if they contest his competence) the burden of rebutting it” and that, “[b]y its terms, the presumption of competence is one which affects the burden of proof.” 51 Cal. 3d, at 885, 799 P. 2d, at 1291. We see no reason to disturb the Caiifor-nia Supreme Court’s conclusion that, in essence, the challenged presumption is a restatement of the burden of proof, and it follows from what we have said that the presumption does not violate the Due Process Clause.
Nothing in today’s decision is inconsistent with our longstanding recognition that the criminal trial of an incompetent defendant violates due process. Drope v. Missouri, 420 U. S., at 172-173; Pate v. Robinson, 383 U. S., at 386; see also Riggins v. Nevada, 504 U. S. 127, 139 (1992) (Kennedy, J., concurring in judgment). Rather, our rejection of petitioner’s challenge to § 1369(f) is based on a determination that the California procedure is “constitutionally adequate” to guard against such results, Drope v. Missouri, supra, at 172, and reflects our considered view that “[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 ha[s] been left to the legislative branch,” Patterson v. New York, supra, at 210.
The judgment of the Supreme Court of California is
Affirmed.