dissenting.
Respondent was convicted of violating California Health and Safety Code § 11532 which prohibits furnishing narcotics to a minor. The only issue at his trial was *190whether he had in fact furnished Porter, a minor, with marihuana. On the direct testimony, it does not appear that he could have been constitutionally convicted, for it seems that there would have been insufficient evidence to sustain a finding of guilt. The State presented three witnesses to prove respondent’s guilt: Porter and Officers Wade and Dominguez. As the Court states, Porter testified at trial that “he was uncertain how he obtained the marihuana, primarily because he was at the time on 'acid’ (LSD), which he had taken 20 minutes before respondent phoned. Porter claimed that he was unable to remember the events that followed the phone call, and that the drugs he had taken prevented his distinguishing fact from fantasy.” Ante, at 152. Officer Wade had no personal knowledge of the facts of the alleged offense; he was able only to report the content of an extrajudicial statement that Porter had made to him. Officer Dominguez testified about an incident wholly separate from the alleged offense; his testimony was consistent with the defense account of the facts.1
Thus, the evidence on which respondent was found guilty consisted of two pretrial statements by Porter. The first was the account given Officer Wade. It was unsworn and not subject to defense cross-examination. Porter’s demeanor while making the statement was not observed by the trial factfinder. The statement was made under unreliable circumstances — it was taken four days after Porter’s arrest for selling marihuana to an undercover agent and while he was still in custody.2 No *191written transcript of the statement was .introduced at trial. Officer Wade recounted it simply as he remembered Porter’s words.3 The second statement was given by Porter during respondent’s preliminary hearing. It was sworn and subject to cross-examination. Defense counsel, however, did not engage in a searching examination.4 Again, Porter’s demeanor while he made this statement was unobserved by the trial factfinder. The statement was put before this factfinder, of course, when at various points during Porter’s direct examination at trial the prosecutor read excerpts from his preliminary hearing testimony.
Accordingly, the facts of this case present two questions regarding the application of California Evidence Code § 1235: first, whether the Confrontation Clause permits a witness’ extrajudicial statement to be admitted at trial as substantive evidence when the witness claims to be unable to remember the events with which his prior statement dealt, and, second, whether the clause permits a witness’ preliminary hearing statement, made under oath and subject to cross-examination, to be introduced at trial as substantive evidence when the witness claims to be unable to remember the events with which the statement dealt. In my view, neither statement can be introduced without unconstitutionally restricting the right of the accused to challenge incriminating evidence in the presence of the factfinder who will determine his guilt or innocence.
*192I
The Court points out that “the particular vice that gave impetus to the confrontation claim was the practice of trying defendants on 'evidence’ which consisted solely of ex parte affidavits or depositions secured by the examining magistrates, thus denying the defendant the opportunity to challenge his accuser in a face-to-face encounter in front of the trier of fact.” Ante, at 156. A face-to-face encounter, of course, is important, not so that the accused can view at trial his accuser’s visage, but so that he can directly challenge the accuser’s testimony before the factfinder. See 5 J. Wigmore, Evidence §§ 1364, 1365 (3d ed. 1940). We made this clear in Mattox v. United States, 156 U. S. 237, 242-243 (1895), where we stressed the necessity of “a personal examination and cross-examination of the witness in which the accused has an opportunity, not only of testing the recollection and sifting the conscience of the witness, but of compelling him to stand face to face with the jury in order that they may look at him, and judge by his demeanor upon the stand and the manner in which he gives his testimony whether he is worthy of belief.”
There is no way to test the recollection and sift the conscience of a witness regarding the facts of an alleged offense if he is unwilling or unable to be questioned about them;5 defense counsel cannot probe the story of a silent witness and attempt to expose facts that qualify or discredit it. The impetus to truth inherent in the oath sworn by the witness, in the penalty for perjury, and in *193the serious purpose of the courtroom have no effect on him so far as the facts of the alleged offense are concerned. Nor, obviously, can the factfinder view his demeanor while he recounts the facts. If the witness claims that he is unable to remember the pertinent events, it is true that this assertion can be challenged, and that in making and defending it the witness will be affected by his oath, the penalty for perjury, and the courtroom atmosphere. It is equally true that the trial factfinder can observe and weigh the witness’ demeanor as he makes and defends such a claim. But a decision by the factfinder that the witness is lying sheds no direct light on the accuracy of any pretrial statement made by him; that statement remains without the support or discredit that can come only from the probing of its factual basis while the witness stands face to face with the accused and the factfinder. If the factfinder decides that the witness is honestly unable to remember the events in question, that conclusion may or may not directly guide the factfinder in assessing the reliability of the pretrial statement. If, for example, the witness were unable to remember the pertinent facts because he was under the influence of drugs at the time they occurred, the factfinder might reasonably disregard any pretrial account of these events given by the witness.
This Court has already explicitly held in Douglas v. Alabama, 380 U. S. 415, 419-420 (1965), that the Confrontation Clause forbids the substantive use at trial of a prior extrajudicial statement, when the declarant is present at trial but unwilling to testify about the events with which his prior statement dealt. In Douglas the prosecution introduced the alleged confession of the accused’s supposed accomplice, one Loyd, who was unwilling to testify about the pertinent events for fear of self-incrimination. We held that “petitioner’s inability to cross-examine Loyd as to the alleged confession plainly denied *194him the right of cross-examination secured by the Confrontation Clause. Loyd’s alleged statement that the petitioner fired the shotgun constituted the only direct evidence that he had done so ... . [E]ffective confrontation of Loyd was possible only if Loyd affirmed the statement as his. However, Loyd did not do so, but relied on his privilege to refuse to answer.”
For purposes of the Confrontation Clause, there is no significant difference between a witness who fails to testify about an alleged offense because he is unwilling to do so and a witness whose silence is compelled by an inability to remember. Both are called to the stand to testify. The jury may view the demeanor of each as he indicates why he will not discuss the crucial events. But in neither instance are the purposes of the Confrontation Clause satisfied, because the witness cannot be questioned at trial concerning the pertinent facts. In both cases, if a pretrial statement is introduced for the truth of the facts asserted, the witness becomes simply a conduit for the admission of stale evidence, whose reliability can never be tested before the trial factfinder by cross-examination of the declarant about the operative events, and by observation of his demeanor as he testifies about them.
Unlike the Court, I see no reason to leave undecided the inadmissibility of Porter’s statements to Officer Wade. We have before us the transcript of Porter’s trial testimony. He could not remember the operative events. Whether he feigned loss of memory is irrelevant to respondent’s confrontation claim. Under Douglas his statement to Officer Wade must be excluded as substantive evidence.6
*195II
The question remains whether the fact that a pretrial statement was obtained at a preliminary hearing, under oath and subject to cross-examination, distinguishes that statement for confrontation purposes from an extrajudicial statement. I thought that our decision in Barber v. Page, 390 U. S. 719 (1968), resolved this issue. In Barber we stated that confrontation at a preliminary hearing cannot compensate for the absence of confrontation at trial, because the nature and objectives of the two proceedings differ significantly. In that case, the prosecution argued that the accused had waived his right to cross-examination at the preliminary hearing. Though we rejected that argument, to put beyond doubt the necessity for confrontation at trial, we stated:
“Moreover, we would reach the same result on the facts of this case had petitioner’s counsel actually cross-examined [the witness] at the preliminary hearing. . . . The right to confrontation is basically a trial right. It includes both the opportunity to cross-examine and the occasion for the jury to weigh the demeanor of the witness. A preliminary hearing is ordinarily a much less searching exploration into the merits of a case than a trial, simply because its function is the more limited one of determining whether probable cause exists to hold the accused for trial.” Id., at 725.7
*196We applied Barber retroactively in Berger v. California, 393 U. S. 314 (1969), a case in which defense counsel did have an opportunity to cross-examine the witness at the preliminary hearing. We held, nonetheless, that “[cjlearly, petitioner’s inability to cross-examine ... at trial may have had a significant effect on the 'integrity of the fact-finding process.’ ” Id., at 315.
Preliminary hearings in California are not atypical in their nature and objectives:
“In most California criminal prosecutions the preliminary examination is conducted as a rather perfunctory uncontested proceeding with only one likely denouement — an order holding the defendant for trial. Only television lawyers customarily demolish the prosecution .in the magistrate’s court. The prosecution need show only 'probable cause,’ a burden vastly lighter than proof beyond a reasonable doubt.” People v. Gibbs, 255 Cal. App. 2d 739, 743-744, 63 Cal. Rptr. 471, 475 (1967).
It follows that the purposes of the Confrontation Clause cannot be satisfied by a face-to-face encounter at *197the preliminary hearing. Cross-examination at the hearing pales beside that which takes place at trial. This is so for a number of reasons. First, as noted, the objective of the hearing is to establish the presence or absence of probable cause, not guilt or innocence proved beyond a reasonable doubt; thus, if evidence suffices to establish probable cause, defense counsel has little reason at the preliminary hearing to show that it does not conclusively establish guilt — or, at least, he had little reason before today’s decision. Second, neither defense nor prosecution is eager before trial to disclose its case by extensive examination at the preliminary hearing; thorough questioning of a prosecution witness by defense counsel may easily amount to a grant of gratis discovery to the State. Third, the schedules of neither court nor counsel can easily accommodate lengthy preliminary hearings. Fourth, even were the judge and lawyers not concerned that the proceedings be brief, the defense and prosecution have generally had inadequate time before the hearing to prepare for extensive examination. Finally, though counsel were to engage in extensive questioning, a part of its force would never reach the trial factfinder, who would know the examination only second hand. As the California Supreme Court stated:
“[L]ost in a cold reading of the preliminary transcript is the more subtle yet undeniable effect of counsel’s rhetorical style, his pauses for emphasis and his variations in tone, as well as his personal rapport with the jurors, as he pursues his ^cross-examination. For example, . . . while the lawyer 'must keep control of himself . . . [t]his does not mean that the cross-examiner never should fight with a witness, raise his voice, or become angry. Forensic indignation, whether expressed physically or verbally, may produce good results in special circumstances.’ In addition, counsel may well conduct *198his cross-examination in a different manner before a committing magistrate than before a trial court or jury. Thus, . . . counsel must always temper his cross-examination to the individual jurors, using their reactions as a guide to the most effective line of questioning. 'The cross-examiner must remember that he is a performer and the jurors are his audience. No good performer ignores his audience, and all performances are conducted for the purpose of favorably impressing the audience.’. . . We conclude that experience demonstrates the essentiality of truly contemporaneous cross-examination.” 70 Cal. 2d, at 662-663, 451 P. 2d, at 427.
If cross-examination at the preliminary hearing rarely approximates that at trial, observation by the trial fact-finder of the witness’ demeanor as he gives his prior testimony is virtually nonexistent. Unless the committing magistrate is also the trial factfinder, the demeanor purpose of the Confrontation Clause is wholly negated by substituting confrontation at the preliminary hearing for confrontation at trial. And yet, in the words of the California court, "[i]t is because demeanor— attitude and manner — is a significant factor in weighing testimonial evidence that it is axiomatic the trier of fact, before whom the witness testified and was cross-examined ... , is the sole judge of the credibility of a witness and of the weight to be given his testimony.” Id,., at 662, 451 P. 2d, at 427. No such determination of credibility is possible when the witness comes before the trial factfinder by the reading of a cold transcript.
It appears, then, that in terms of the purposes of the Confrontation Clause, an equation of face-to-face encounter at the preliminary hearing with confrontation at trial must rest largely on the fact that the witness testified *199at the hearing under oath, subject to the penalty for perjury, and in a courtroom atmosphere. These factors are not insignificant, but by themselves they fall far short of satisfying the demands of constitutional confrontation. Moreover, the atmosphere and stakes are different in the two proceedings. In the hurried, somewhat pro forma context of the average preliminary hearing, a witness may be more careless in his testimony than in the more measured and searching atmosphere of a trial. Similarly, a man willing to perjure himself when the consequences are simply that the accused will stand trial may be less willing to do so when his lies may condemn the defendant to loss of liberty. In short, it ignores reality to assume that the purposes of the Confrontation Clause are met during a preliminary hearing. Accordingly, to introduce preliminary hearing testimony for the truth of the facts asserted, when the witness is in court and either unwilling or unable to testify regarding the pertinent events, denies the accused his Sixth Amendment right to grapple effectively with incriminating evidence.
The Court’s ruling, moreover, may have unsettling effects on the nature and objectives of future preliminary hearings. The California Court defined the problem: “Were we to equate preliminary and trial testimony one practical result might be that the preliminary hearing, designed to afford an efficient and speedy means of determining the narrow question of probable cause, would tend to develop into a full-scale trial. This would invite thorough and lengthy cross-examination, with the consequent necessity of delays and continuances to bring in rebuttal and impeachment witnesses, to gather all available evidence, and to assure generally that nothing remained for later challenge. In time this result would prostitute the accepted purpose of pre*200liminary hearings and might place an intolerable burden on the time and resources of the courts of first instance.” 70 Cal. 2d, at 664, 451 P. 2d, at 428.
Conscientious defense counsel, aware that today’s decision has increased the likelihood of the use of preliminary hearing testimony at trial, may well wish to conduct a full-scale, unlimited cross-examination of prosecution witnesses at the hearing. We held in Coleman v. Alabama, ante, p. 1, that an accused has a right to assistance of counsel during a preliminary hearing. And we have made clear that “it is a denial of the accused’s constitutional right to a fair trial to force him to trial with such expedition as to deprive him of the effective aid and assistance of counsel.” White v. Ragen, 324 U. S. 760, 764 (1945). In light of today’s decision, may defense counsel be denied requests for delay that are reasonably necessary to enable him to conduct a thorough examination at the preliminary hearing? What limits, if any, may still be placed on the defense’s use of the preliminary hearing as a discovery device to extract information from the prosecution that is reasonably necessary, not to a determination of probable cause, but to a rigorous examination of government witnesses? Do the requisites of “effective assistance of counsel” require defense counsel to conduct such an examination? 8
*201The Court relies heavily on the traditional practice of admitting the prior testimony of a witness who is physically unavailable at trial. It finds no ground for distinguishing between the pretrial declarant who fails to testify at trial because he is not physically present and the pretrial declarant who, though present at trial, fails to testify because he is unwilling or unable to do so. The Court reasons that the “necessity” for the introduction of either declarant’s prior statement is “the State’s ‘need’ to introduce relevant evidence,” and that the testimony’s “reliability” rests “on the circumstances under which it was given — circumstances that remain unaffected regardless of whether the witness is present or absent at the later trial.” Ante, at 167 n. 16. I disagree.
The State, obviously, does need to introduce relevant evidence. But the “necessity” that justifies the admission of pretrial statements is not the prosecution’s need to convict, but the factfinder’s need to be presented with reliable evidence to aid its determination of guilt or innocence. Whethér a witness’ assertions are reliable ordinarily has little or no bearing on their admissibility, for they are subject to the corrective influences of his demeanor and cross-examination. If, however, there is no possibility that his assertions can be so tested at trial, then their reliability becomes an important factor in deciding whether to permit their presentation to the factfinder. When a probability exists that incriminating pretrial testimony is unreliable, its admission, absent confrontation, will prejudicially distort the factfinding process.
The reliability of pretrial testimony, in turn, is not determined simply by the circumstances under which it *202was given. It is also influenced by subsequent developments. If, for example, prior testimony is later disavowed by the declarant in an extrajudicial but convincing statement, it would be unrealistic to argue at a later trial, from which the declarant was physically absent, that the reliability of his prior testimony was unaffected by the intervening event.
The subsequent developments under consideration here are (1) failure to testify at trial because of physical unavailability and (2) failure to testify because of unwillingness to do so or inability to remember. In my view, these developments have very different implications for the reliability of prior testimony. Physical unavailability is generally a neutral factor; in most instances, it does not cast doubt on the witness’ earlier assertions. Inability to remember the pertinent events, on the other hand, or unwillingness to testify about them, whether because of feigned loss of memory or fear of self-incrimination, does cast such doubt. Honest inability to remember at trial raises serious question about clarity of memory at the time of the pretrial statement. The deceit inherent in feigned loss of memory lessens confidence in the probity of prior assertions. And fear of self-incrimination at trial suggests that the witness may have shaped prior testimony so as to avoid dangerous consequences for himself. Reliability cannot be assumed simply because a prior statement was made at a preliminary hearing.
In sum, I find that Porter’s real or pretended lapse of memory about the pertinent events casts serious doubt upon the reliability of his preliminary hearing testimony. It is clear that so long as a witness, such as Porter, cannot or will not testify about these events at trial, the accused remains unable to challenge effectively that witness’ prior assertions about them. The probable unreliability of the prior testimony, coupled with the im*203possibility of its examination during trial, denies the accused his right to probe and attempt to discredit incriminating evidence. Accordingly, I would hold California Evidence Code § 1235 in violation of the Confrontation Clause to the extent that it permits the substantive use at trial of prior statements, whether extrajudicial or testimonial, when the declarant is present at trial but unable or unwilling to be questioned about the events with which the prior statements dealt. I would therefore affirm the reversal of respondent’s conviction.
See People v. Green, 70 Cal. 2d 654, 657-658, 451 P. 2d 422, 424 (1969).
Porter declared under oath on May. 12„ 1967, that “when I was arrested and was in custody, the police kept telling me that they knew it was JOHN GREEN I was involved with and that unless I implicated him that they would see that I was out of circulation for a long time ...”
Cf. Goldberg v. Kelly, 397 U. S. 254, 269 (1970), where the Court stated that “[t]he second-hand presentation, to the decision maker by the caseworker has its own deficiencies; since the caseworker usually gathers the facts upon which the charge of ineligibility rests, the presentation of the recipient’s side of the controversy cannot safely be left to him.”
No question, for example, was asked Porter by either the defense or prosecution as to whether he was under the influence of drugs at the time of the alleged offense.
If, on the other hand, the witness is willing and able to testify at trial about the operative events, the demands of the Confrontation Clause may be met, even though the witness contradicts his pretrial assertions. I see no need on the facts presented here, however, to resolve this issue.
The fact that in appropriate circumstances such a statement may be admitted to impeach a witness is not as anomalous as the Court suggests, ante, at 164. If, for example, Porter’s pretrial statements *195had been admitted at respondent’s trial solely for impeachment purposes, they would not have provided substantive proof of his guilt, and, as noted, there would then very likely have been insufficient evidence to sustain his conviction.
The California Supreme Court in the present case discussed in more detail the distinctions between a preliminary hearing and trial, stating that “the purpose of a preliminary hearing is not a full exploration of the merits of a cause or of the testimony of the witnesses. It is designed and adapted solely to answer the *196far narrower preliminary question of whether probable cause exists for a subsequent trial. The judge in preliminary proceedings is not required to be convinced of the defendant’s guilt ‘beyond a reasonable doubt,’ but need only look for reasonable credibility in the charge against him. A fortiori a witness’ testimony, though the only evidence adduced, need not be convincing or credible beyond a reasonable doubt, and cross-examination which would surely impeach a witness at trial would not preclude a finding of probable cause at the preliminary stage. Even given the opportunity , . . neither prosecution nor defense is generally willing or able to fire all its guns at this early stage of the proceedings, for considerations both of time and efficacy. . . . Indeed, it is seldom that either party has had time for investigation to obtain possession of adequate information to pursue in depth direct or cross-examination.” 70 Cal. 2d, at 663, 451 P. 2d, at 428. See also Virgin Islands v. Aquino, 378 F. 2d 540, 549 (C. A. 3d Cir. 1967).
Beyond these problems, today’s holding raises another practical difficulty: how extensive must cross-examination at the preliminary hearing be before constitutional confrontation is deemed to have occurred? Is the mere opportunity for face-to-face encounter sufficient? Perhaps so. The Court states that “respondent had every opportunity to cross-examine Porter as to his statement” at the hearing. Ante, at 165. Does that mean that if defense counsel fails to take advantage of the opportunity that the accused can subsequently be convicted at trial on the basis of wholly untested evidence? If more than, an unexercised chance to cross-examine is required, how thorough and effective must the questioning be before it satisfies the Confrontation Clause? Is it significant, *201for example, that in the present case neither the defense nor prosecution explored the most elemental fact about Porter’s testimony — the possibility that he was under the influence of drugs at the time of the alleged offense?