dissenting.
The Court upholds the admission at trial of illegally seized evidence to impeach a defendant’s testimony deliberately elicited by the Government under the cover of impeaching an accused who takes the stand in his own behalf. I dissent. Criminal defendants now told that prosecutors are licensed to insinuate otherwise inadmissible evidence under the guise of cross-examination no longer have the unfettered right to elect whether or not to testify in their own behalf.. Not only is today’s decision an unwarranted departure from prior controlling cases, but, regrettably, it is yet another element in the trend to depreciate the constitutional protections guaranteed the criminally accused.
I
The question before us is not of first impression. The identical issue was confronted in Agnello v. United States, 269 U. S. 20 (1925), which determined — contrary to the instant decision — that it was constitutionally impermissible to admit evidence obtained in violation of the Fourth Amendment to rebut a defendant’s response to a matter first raised during the Government’s cross-examination. Subsequently, Walder v. United States, 347 U. S. 62 (1954), affirmed the introduction of unlawfully acquired evidence to impeach an accused’s false assertions about previous conduct that had been offered during direct testimony. But Walder took pains to draw the distinction between its own holding and Agnello, noting that “the defendant [Walder] went beyond a mere denial of complicity in the crimes of which he was charged and made the sweep*630ing [and untrue] claim that he had never dealt in or possessed any narcotics.” 347 U. S., at 65. In “shar[p] contras[t],” in Agnello, “the Government . . . tried to smuggle [the tainted evidence] ... in on cross-examination,” and “elicit[ed] the expected denial. . . .” 347 U. S., at 66.
The Court’s recent decisions have left Agnello undisturbed. Harris v. New York, 401 U. S. 222 (1971), allowed the government to use inadmissible uncounseled statements to impeach direct examination. So, too, Oregon v. Hass, 420 U. S. 714 (1975), reaffirmed Harris in the context of impeachment of the defendant’s direct testimony. Significantly, neither decision intimated that Agnello had lost vitality, or that the distinction emphasized by Walder had been effaced.
The Court’s opinion attempts to discredit Agnello by casting a strawman as its holding, and then demolishing the pitiful scarecrow of its own creation. Specifically, the Court cites Agnello’s quotation of language from Silverthorne Lumber Co. v. United States, 251 U. S. 385, 392 (1920), that “illegally seized evidence 'shall not ... be used at all,’ ” ante, at 624, and then refers to the subsequent decisions that indeed permit limited use of that evidence for impeachment. But the actual principle of Agnello, as discerned by Walder, is that the Government may not employ its power of cross-examination to predicate the admission of illegal evidence. In other words, impeachment by cross-examination about — or introduction of— suppressible evidence must be warranted by defendant’s statements upon direct questioning. That principle is not at all inconsistent with later cases holding that the defendant may not take advantage of evidentiary suppression to advance specific perjurious claims as part of his direct case.
Nor is it correct to read Agnello as turning upon the tenuity of the link between the cross-examination involved there and the subject matter of the direct examination. Ante, at 625. The cross-examination about Agnello’s previous connection with cocaine was reasonably related to his direct testimony that he lacked knowledge that the commodity he was trans*631porting was cocaine. 269 U. S., at 29-30. For “[t]he possession by Frank Agnello of the can of cocaine which was seized tended to show guilty knowledge and criminal intent on his part. . . .” Id., at 35. Thus, the constitutional flaw found in Agnello was that the introduction of the tainted evidence had been prompted by statements of the accused first elicited upon cross-examination. And the case was so read in Walder v. United States. That decision specifically stated that a defendant “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. Since as a matter of the law of evidence it would be perfectly permissible to cross-examine a defendant as to his denial of complicity in the crime, the quoted passage in Walder must be understood to impose a further condition before the prosecutor may refer to tainted evidence — that is, some particular direct testimony by the accused that relies upon “the Government’s disability to challenge his credibility.” Ibid.
In fact, the Court’s current interpretation of Agnello and Walder simply trivializes those decisions by transforming their Fourth Amendment holdings into nothing more than a constitutional reflection of the common-law evidentiary rule of relevance.
Finally, the rationale of Harris v. New York and Oregon v. Hass does not impel the decision at hand. The exclusionary rule exception established by Harris and Hass may be fairly easily cabined by defense counsel’s willingness to forgo certain areas of questioning. But the rule prescribed by the Court in this case passes control of the exception to the Government, since the prosecutor can lay the predicate for admitting otherwise suppressible evidence with his own questioning. To be sure, the Court requires that cross-examination be “proper”; however, traditional evidentiary principles accord parties fairly considerable latitude in cross-*632examining opposing witnesses. See C. McCormick, Law of Evidence §§ 21-24 (2d ed. 1972).1 In practical terms, therefore, today’s holding allows even the moderately talented prosecutor to “work in . . . evidence on cross-examination [as it would] in its case in chief. . . .” Walder v. United States, 347 U. S., at 66. To avoid this consequence, a defendant will be compelled to forgo testifying on his own behalf.
“[T]he Constitution guarantees a defendant the fullest opportunity to meet the accusation against him.” Id., at 65; see Harris v. New York, supra, at 229-230 (Brennan, J., dissenting). Regrettably, surrender of that guarantee is the price the Court imposes for the defendant to claim his right not to be convicted on the basis of evidence obtained in violation of the Constitution.2 I cannot agree that one constitutional privilege must be purchased at the expense of another.
II
The foregoing demonstration of its break with precedent provides a sufficient ground to condemn the present ruling— unleashing, as it does, a hitherto relatively confined exception to the exclusionary rule. But I have a more fundamental difference with the Court’s holding here, which culminates *633the approach taken in Harris v. New York and Oregon v. Hass. For this sequence of decisions undercuts the constitutional canon that convictions cannot be procured by governmental lawbreaking. See Harris v. New York, 401 U. S., at 226-232 (Brennan, J., dissenting); Oregon v. Hass, 420 U. S., at 724-725 (Brennan, J., dissenting).
“ ‘[I]t is monstrous that courts should aid or abet the lawbreaking police officer.’ ” Id., at 724, quoting Harris v. New York, supra, at 232 (Brennan, J., dissenting). And what is especially troubling about these cases is the mode of analysis employed by the Court. In each, the judgment that tainted evidence may be admitted has been bottomed upon a determination that the “incremental furthering” of constitutional ends would not be sufficient to warrant exclusion of otherwise probative evidence. Ante, at 627; see Oregon v. Hass, supra, at 721; Harris v. New York, supra, at 225.
Of course, “[tjhere is no gainsaying that arriving at the truth is a fundamental goal of our legal system.” Ante, at 626. But it is also undeniable that promotion of that objective must be consonant with other ends, in particular those enshrined in our Constitution. I still hope that the Court would not be prepared to acquiesce in torture or other police conduct that “shocks the conscience” even if it demonstrably advanced the factfinding process. At any rate, what is important is that the Constitution does not countenance police misbehavior, even in the pursuit of truth. The processes of our judicial system may not be fueled by the illegalities of government authorities. See, e. g., Mapp v. Ohio, 367 U. S. 643 (1961).
Nevertheless, the Court has undertaken to strike a “balance” between the “policies” it finds in the Bill of Rights and the “competing interesft]” in accurate trial determinations. Ante, at 627. This balancing effort is completely freewheeling. Far from applying criteria intrinsic to the Fourth and Fifth Amendments, the Court resolves succeeding cases simply by declaring that so much exclusion is enough to deter *634police misconduct. Ante, at 626, 627; see Oregon v. Hass, supra, at 721; Harris v. New York, supra, at 225; cf. Stone v. Powell, 428 U. S. 465, 486-489 (1976); United States v. Calandra, 414 U. S. 338, 350-352 (1974). That hardly conforms to the disciplined analytical method described as “legal reasoning,” through which judges endeavor to formulate or derive principles of decision that can be applied consistently and predictably.
Ultimately, I fear, this ad hoc approach to the exclusionary rule obscures the difference between judicial decisionmaking and legislative or administrative policymaking. More disturbingly, by treating Fourth and Fifth Amendment privileges as mere incentive schemes, the Court denigrates their unique status as constitutional protections. Yet the efficacy of the Bill of Rights as the bulwark of our national liberty depends precisely upon public appreciation of the special character of constitutional prescriptions. The Court is charged with the responsibility to enforce constitutional guarantees; decisions such as today’s patently disregard that obligation.
Accordingly, I dissent.
Federal Rule of Evidence 611 does provide for limitation of the scope of cross-examination “to the subject matter of the direct examination and matters affecting the credibility of the witness.” But even these constraints need not be adopted by the States, which are generally free to fashion their own rules of evidence.
Although evidence of prior inconsistent utterances or behavior may ostensibly be offered merely to attack a defendant’s credibility by contradicting his trial testimony, such evidence can also serve to buttress the affirmative elements of the prosecution’s case. Thus, almost anytime an accused takes the stand, the prosecution will have an opportunity to enhance its case in chief. And it is unrealistic to assume that limiting instructions will afford the defendant significant protection. Cf. Bruton v. United States, 391 U. S. 123 (1968).