delivered the opinion of the Court.

We granted the writ in this case to consider petitioner’s claim that a statement made by him to police under circumstances rendering it inadmissible to establish the prosecution’s case in chief under Miranda v. Arizona, 384 U. S. 436 (1966), may not be used to impeach his credibility.

The State of New York charged petitioner in a two-count indictment with twice selling heroin to an under*223cover police officer. At a subsequent jury trial the officer was the State’s chief witness, and he testified as to details of the two sales. A second officer verified collateral details of the sales, and a third offered testimony about the chemical analysis of the heroin.

Petitioner took the stand in his own defense. He admitted knowing the undercover police officer but denied a sale on January 4, 1966. He admitted making a sale of contents of a glassine bag to the officer on January 6 but claimed it was baking powder and part of a scheme to defraud the purchaser.

On cross-examination petitioner was asked seriatim whether he had made specified statements to the police immediately following his arrest on January 7 — statements that partially contradicted petitioner’s direct testimony at trial. In response to the cross-examination, petitioner testified that he could not remember virtually any of the questions or answers recited by the prosecutor. At the request of petitioner’s counsel the written statement from which the prosecutor had read questions and answers in his impeaching process was placed in the record for possible use on appeal; the statement was not shown to the jury.

The trial judge instructed the jury that the statements attributed to petitioner by the prosecution could be considered only in passing on petitioner’s credibility and not as evidence of guilt. In closing summations both counsel argued the substance of the impeaching statements. The jury then found petitioner guilty on the second count of the indictment.1 The New York Court of Appeals affirmed in a per curiam opinion, 25 N. Y. 2d 175, 250 N. E. 2d 349 (1969).

At trial the prosecution made no effort in its case in chief to use the statements allegedly made by petitioner, *224conceding that they were inadmissible under Miranda v. Arizona, 384 U. S. 436 (1966). The transcript of the interrogation used in the impeachment, but not given to the jury, shows that no warning of a right to appointed counsel was given before questions were put to petitioner when he was taken into custody. Petitioner makes no claim that the statements made to the police were coerced or involuntary.

Some comments in the Miranda opinion can indeed be read as indicating a bar to use of an uncounseled statement for any purpose, but discussion of that issue was not at all necessary to the Court’s holding and cannot be regarded as controlling. Miranda barred the prosecution from making its case with statements of an accused made while in custody prior to having or effectively waiving counsel. It does not follow from Miranda that evidence inadmissible against an accused in the prosecution’s case in chief is barred for all purposes, provided of course that the trustworthiness of the evidence satisfies legal standards.

In Walder v. United States, 347 U. S. 62 (1954), the Court permitted physical evidence, inadmissible in the case in chief, to be used for impeachment purposes.

“It is one thing to say that the Government cannot make an affirmative use of evidence unlawfully obtained. It is quite another to say that the defendant can turn the illegal method by which evidence in the Government’s possession was obtained to his own advantage, and provide himself with a shield against contradiction of his untruths. Such an extension of the Weeks doctrine would be a perversion of the Fourth Amendment.

“[T]here is hardly justification for letting the defendant affirmatively resort to perjurious testimony in reliance on the Government’s disability to challenge his credibility.” 347 U. S., at 65.

*225It is true that Walder was impeached as to collateral matters included in his direct examination, whereas petitioner here was impeached as to testimony bearing more directly on the crimes charged. We are not persuaded that there is a difference in principle that warrants a result different from that reached by the Court in Walder. Petitioner's testimony in his own behalf concerning the events of January 7 contrasted sharply with what he told the police shortly after his arrest. The impeachment process here undoubtedly provided valuable aid to the jury in assessing petitioner’s credibility, and the benefits of this process should not be lost, in our view, because of the speculative possibility that impermissible police conduct will be encouraged thereby. Assuming that the exclusionary rule has a deterrent effect on proscribed police conduct, sufficient deterrence flows when the evidence in question is made unavailable to the prosecution in its case in chief.

Every criminal defendant is privileged to testify in his own defense, or to refuse to do so. But that privilege cannot be construed to include the right to commit perjury. See United States v. Knox, 396 U. S. 77 (1969); cf. Dennis v. United States, 384 U. S. 855 (1966). Having voluntarily taken the stand, petitioner was under an obligation to speak truthfully and accurately, and the prosecution here did no more than utilize the traditional truth-testing devices of the adversary process.2 Had *226inconsistent statements been made by the accused to some third person, it could hardly be contended that the conflict could not be laid before the jury by way of cross-examination and impeachment.

The shield provided by Miranda cannot be perverted into a license to use perjury by way of a defense, free from the risk of confrontation with prior inconsistent utterances. We hold, therefore, that petitioner’s credibility was appropriately impeached by use of his earlier conflicting statements.

Affirmed.

Me. Justice Black dissents.

with whom Mr. Justice Douglas and Mr. Justice Marshall join, dissenting.

It is conceded that the question-and-answer statement used to impeach petitioner’s direct testimony was, under Miranda v. Arizona, 384 U. S. 436 (1966), constitutionally inadmissible as part of the State’s direct case against petitioner. I think that the Constitution also denied the State the use of the statement on cross-examination to impeach the credibility of petitioner’s testimony given in his own defense. The decision in Walder v. United States, 347 U. S. 62 (1954), is not, as the Court today holds, dispositive to the contrary. Rather, that case supports my conclusion.

The State’s case against Harris depended upon the jury’s belief of the testimony of the undercover agent that petitioner “sold” the officer heroin on January 4 and again on January 6. Petitioner took the stand and flatly denied having sold anything to the officer on January 4. He countered the officer’s testimony as to the January 6 sale with testimony that he had sold the officer two glassine bags containing what appeared to be heroin, but that actually the bags contained only baking powder intended to deceive the officer in order to obtain $12. *227The statement contradicted petitioner’s direct testimony as to the events of both days. The statement’s version of the events on January 4 was that the officer had used petitioner as a middleman to buy some heroin from a third person with money furnished by the officer. The version of the events on January 6 was that petitioner had again acted for the officer in buying two bags of heroin from a third person for which petitioner received $12 and a part of the heroin. Thus, it is clear that the statement was used to impeach petitioner’s direct testimony not on collateral matters but on matters directly related to the crimes for which he was on trial.1

Walder v. United States was not a case where tainted evidence was used to impeach an accused’s direct testimony on matters directly related to the case against him. In Walder the evidence was used to impeach the accused’s testimony on matters collateral to the crime charged. Walder had been indicted in 1950 for purchasing and possessing heroin. When his motion to suppress use of the narcotics as illegally seized was granted, the Government dismissed the prosecution. Two years later Walder was indicted for another narcotics violation completely unrelated to the 1950 one. Testifying in his own defense, he said on direct examination that he had never in his life possessed narcotics. On cross-examination he denied that law enforcement officers had seized narcotics from his home two years earlier. The Government was then permitted to introduce the testimony of one of the officers involved in the 1950 seizure, that when he had raided Walder’s home at that time he had seized narcotics there. *228The Court held that on facts where “the defendant went beyond a mere denial of complicity in the crimes of which he was charged and made the sweeping claim that he had never dealt in or possessed any narcotics,” 347 U. S., at 65, the exclusionary rule of Weeks v. United States, 232 U. S. 383 (1914), would not extend to bar the Government from rebutting this testimony with evidence, although tainted, that petitioner had in fact possessed narcotics two years before. The Court was careful, however, to distinguish the situation of an accused whose testimony, as in the instant case, was- a “denial of complicity in the crimes of which he was charged,” that is, where illegally obtained evidence was used to impeach the accused’s direct testimony on matters directly related to the case against him. As to that situation, the Court said:

“Of course, the Constitution guarantees a defendant the fullest opportunity to meet the accusation against him. He must be free to deny all the elements of the case against him without thereby giving leave to the Government to introduce by way of rebuttal evidence illegally secured by it, and therefore not available for its case in chief.” 347 U. S., at 65.

From this recital of facts it is clear that the evidence used for impeachment in Walder was related to the earlier 1950 prosecution and had no direct bearing on “the elements of the case” being tried in 1952. The evidence tended solely to impeach the credibility of the defendant’s direct testimony that he had never in his life possessed heroin. But that evidence was completely unrelated to the indictment on trial and did not in any way interfere with his freedom to deny all elements of that case against him. In contrast, here, the evidence used for impeachment, a statement concerning the details of the very sales alleged in the indictment, was directly related to the case against petitioner.

*229While Walder did not identify the constitutional specifics that guarantee “a defendant the fullest opportunity to meet the accusation against him . . . [and permit him to] be free to deny all the elements of the case against him,” in my view Miranda v. Arizona, 384 U. S. 436 (1966), identified the Fifth Amendment’s privilege against self-incrimination as one of those specifics.2 *230That privilege has been extended against the States. Malloy v. Hogan, 378 U. S. 1 (1964). It is fulfilled only when an accused is guaranteed the right “to remain silent unless he chooses to speak in the unfettered exercise of his own will,” id., at 8 (emphasis added). The choice of whether to testify in one’s own defense must therefore be “unfettered,” since that choice is an exercise of the constitutional privilege, Griffin v. California, 380 U. S. 609 (1965). Griffin held that comment by the prosecution upon the accused’s failure to take the stand or a court instruction that such silence is evidence of guilt is impermissible because it “fetters” that choice — “[i]t cuts down on the privilege by making its assertion costly.” Id., at 614. For precisely the same reason the constitutional guarantee forbids the prosecution to use a tainted statement to impeach the accused who takes the stand: The prosecution’s use of the tainted statement “cuts down on the privilege by making its assertion costly.” Ibid. Thus, the accused is denied an “unfettered” choice when the decision whether to take the stand is burdened by the risk that an illegally obtained prior statement may be introduced to impeach his direct testimony denying complicity in the crime charged against him.3 We settled this proposition in Miranda where we said:

“The privilege against self-incrimination protects the individual from being compelled to incriminate himself in any manner .... [Statements merely intended to be exculpatory by the defendant are often used to impeach his testimony at trial . . . . These statements are incriminating in any meaningful sense of the word and may not be used without the full warnings and effective waiver required for *231any other statement.” 384 U. S., at 476-477 (emphasis added).

This language completely disposes of any distinction between statements used on direct as opposed to cross-examination.4 “An incriminating statement is as incriminating when used to impeach credibility as it is when used as direct proof of guilt and no constitutional distinction can legitimately be drawn.” People v. Kulis, 18 N. Y. 2d 318, 324, 221 N. E. 2d 541, 543 (1966.) (dissenting opinion).

The objective of deterring improper police conduct is only part of the larger objective of safeguarding the integrity of our adversary system. The “essential mainstay” of that system, Miranda v. Arizona, 384 U. S., at 460, is the privilege against self-incrimination, which for *232that reason has occupied a central place in our jurisprudence since before the Nation’s birth. Moreover, “we may view the historical development of the privilege as one which groped for the proper scope of governmental power over the citizen. . . . All these policies point to one overriding thought: the constitutional foundation underlying the privilege is the respect a government . . . must accord to the dignity and integrity of its citizens.” Ibid. These values are plainly jeopardized if an exception against admission of tainted statements is made for those used for impeachment purposes. Moreover, it is monstrous that courts should aid or abet the law-breaking police officer. It is abiding truth that “[njothing can destroy a government more quickly than its failure to observe its own laws, or worse, its disregard of the charter of its own existence.” Mapp v. Ohio, 367 U. S. 643, 659 (1961). Thus, even to the extent that Miranda was aimed at deterring police practices in disregard of the Constitution, I fear that today’s holding will seriously undermine the achievement of that objective. The Court today tells the police that they may freely interrogate an accused incommunicado and without counsel and know that although any statement they obtain in violation of Miranda cannot be used on the State’s direct case, it may be introduced if the defendant has the temerity to testify in his own defense. This goes far toward undoing much of the progress made in conforming police methods to the Constitution. I dissent.