The Court concludes that because Anita Isaacs’ testimony at respondent’s preliminary hearing was subjected to the equivalent of significant cross-examination, such hearsay evidence bore sufficient “indicia of reliability” to permit its introduction at respondent’s trial without offending the Confrontation Clause of the Sixth Amendment. As the Court recognizes, however, the Constitution imposes the threshold requirement that the prosecution must demonstrate the unavailability of the witness whose prerecorded testimony it wishes to use against the defendant. Because I cannot agree that the State has met its burden of establishing this predicate, I dissent.1
*78“There are few subjects, perhaps, upon which this Court and other courts have been more nearly unanimous than in their expressions of belief that the right of confrontation and cross-examination is an essential and fundamental requirement for the kind of fair trial which is this country’s constitutional goal.” Pointer v. Texas, 380 U. S. 400, 405 (1965). Accord, Berger v. California, 393 U. S. 314, 315 (1969); Barber v. Page, 390 U. S. 719, 721 (1968); Pointer v. Texas, supra, at 410 (Stewart, J., concurring); Kirby v. United States, 174 U. S. 47, 55-56 (1899). Historically, the inclusion of the Confrontation Clause in the Bill of Rights reflected the Framers’ conviction that the defendant must not be denied the opportunity to challenge his accusers in a direct encounter before the trier of fact. See California v. Green, 399 U. S. 149, 156-158 (1970); Park v. Huff, 506 F. 2d 849, 861-862 (CA5 1975) (Gewin, J., concurring). At the heart of this constitutional guarantee is the accused’s right to compel the witness “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.” Mattox v. United States, 156 U. S. 237, 242-243 (1895). See also California v. Green, supra, at 174-183 (Harlan, J., concurring).
Despite the literal language of the Sixth Amendment,2 our cases have recognized the necessity for a limited exception to the confrontation requirement for the prior testimony of a witness who is unavailable at the defendant’s trial. In keeping with the importance of this provision in our constitutional scheme, however, we have imposed a heavy burden on the prosecution either to secure the presence of the witness or to *79demonstrate the impossibility of that endeavor. Barber v. Page, supra, held that the absence of a witness from the jurisdiction does not excuse the State’s failure to attempt to compel the witness’ attendance at trial; in such circumstances, the government must show that it has engaged in a diligent effort to locate and procure the witness’ return. “In short, a witness is not ‘unavailable’ for purposes of the foregoing exception to the confrontation requirement unless the prosecu-torial authorities have made a good-faith effort to obtain his presence at trial.” Id., at 724-725. See, e. g., United States v. Mann, 590 F. 2d 361, 367 (CA1 1978); United States v. Lynch, 163 U. S. App. D. C. 6, 18-19, 499 F. 2d 1011, 1023-1024 (1974); Government of the Virgin Islands v. Aquino, 378 F. 2d 540, 549-552 (CA3 1967). See generally 5 J. Wig-more, Evidence § 1405 (J. Chadbourn rev. 1974) and cases cited therein.
In the present case, I am simply unable to conclude that the prosecution met its burden of establishing Anita Isaacs’ unavailability. From all that appears in the record — and there has been no suggestion that the record is incomplete in this respect — the State’s total effort to secure Anita’s attendance at respondent’s trial consisted of the delivery of five subpoenas in her name to her parents’ residence, and three of those were issued after the authorities had learned that she was no longer living there.3 At least four months before the trial began, the prosecution was aware that Anita had moved away; yet during that entire interval it did nothing whatsoever to try to make contact with her. It is difficult to believe that the State would have been so derelict in attempting to secure the witness’ presence at trial had it not had her *80favorable preliminary hearing testimony upon which to rely in the event of her “unavailability.” The perfunctory steps which the State took in this case can hardly qualify as a “good-faith effort.” In point of fact, it was no effort at all.
The Court, however, is apparently willing to excuse the prosecution’s inaction on the ground that any endeavor to locate Anita Isaacs was unlikely to bear fruit. See ante, at 75-76. I not only take issue with the premise underlying that reasoning — that the improbability of success can condone a refusal to conduct even a cursory investigation into the witness’ whereabouts — but I also seriously question the Court’s conclusion that a bona fide search in the present case would inevitably have come to naught.
Surely the prosecution’s mere speculation about the difficulty of locating Anita Isaacs cannot relieve it of the obligation to attempt to find her. Although the rigor of the undertaking might serve to palliate a failure to prevail, it cannot justify a failure even to try. Just as Barber cautioned that “ ‘the possibility of a refusal is not the equivalent of asking and receiving a rebuff,’ ” 390 TJ. S., at 724 (quoting the decision below, 381 F. 2d 479, 481 (CA10 1966) (Aldrich, J., dissenting)), so, too, the possibility of a defeat is not the equivalent of pursuing all obvious leads and returning empty-handed. The duty of “good-faith effort” would be meaningless indeed “if that effort were required only in circumstances where success was guaranteed.” Mancusi v. Stubbs, 408 U. S. 204, 223 (1972) (Marshall, J., dissenting).
Nor do I concur in the Court’s bleak prognosis of the likelihood of procuring Anita Isaacs’ attendance at respondent’s trial.4 Although Anita’s mother testified that she had no *81current knowledge of her daughter’s whereabouts, the prosecution possessed sufficient information upon which it could have at least initiated an investigation. As the Court acknowledges, one especially promising lead was the San Francisco social worker to whom Mrs. Isaacs had spoken and with whom Anita had filed for welfare. What the Court fails to mention, however, is that the prosecution had more to go on than that datum alone. For example, Mrs. Isaacs testified that on the same day she talked to the social worker, she also spoke to her daughter. And although Mrs. Isaacs told defense counsel that she knew of no way to get in touch with her daughter in an emergency, Tr. 195, in response to a similar question from the prosecutor she indicated that someone in Tucson might be able to contact Anita. Id., at 198-199. It would serve no purpose here to essay an exhaustive catalog of the numerous measures the State could have taken in a diligent attempt to locate Anita. It suffices simply to note that it is not “hindsight,” see ante, at 75, that permits us to envision how a skilled investigator armed with this information (and any additional facts not brought out through the voir dire) 5 might have discovered Anita’s whereabouts *82with reasonable effort. Indeed, precisely because the prosecution did absolutely nothing to try to locate Anita, hindsight does not enhance the vista of investigatory opportunities that were available to the State had it actually attempted to find her.
In sum, what the Court said in Barber v. Page, 390 U. S., at 725, is equally germane here: “[S]o far as this record reveals, the sole reason why [the witness] was not present to testify in person was because the State did not attempt to seek [her] presence. The right of confrontation may not be dispensed with so lightly.”
Because I am convinced that the State failed to lay a proper foundation for the admission of Anita Isaacs’ preliminary hearing testimony, I have no occasion to consider whether that testimony had in fact been subjected to full and effective adverse questioning and whether, even conceding the adequacy of the prior cross-examination, the significant dif*78ferences in the nature and objectives of the preliminary hearing and the trial preclude substituting confrontation at the former proceeding for the constitutional requirement of confrontation at the latter. See California v. Green, 399 U. S. 149, 195-203 (1970) (BeeNnan, J., dissenting).
“In all criminal prosecutions, the accused shall enjoy the right ... to be confronted with the witnesses against him.”
The five subpoenas, all of which were issued to Anita at her parents’ address, showed that returns were made on November 3 and 4, 1975, December 10, 1975, February 3, 1976, and February 25, 1976, respectively. During the course of the voir dire of Anita’s mother, the prosecutor indicated that sometime in November 1975 the Isaacs had told him that Anita had left home. See Tr. 197; ante, at 75.
In attempting to .distinguish this case from Barber v. Page, 390 U. S. 719 (1968), and demonstrate the reasonableness of the State’s conduct, the Court states that “there was no assurance that [Anita] would be found in a place from which she could be forced to return to Ohio.” Ante, at 77. Once located, however, it is extremely unlikely that Anita could- have resisted the State's efforts to secure her return. The Uniform *81Act to Secure the Attendance of Witnesses from Without a State in Criminal Proceedings enables prosecuting authorities in one State to obtain an order from a court in another State compelling the witness’ appearance to testify in court in the first State! The Uniform Act has been adopted in the District of Columbia, the Panama Canal Zone, Puerto Rico, the Virgin Islands, and every State in the Union except Alabama. 11 U. L. A. 1 (Supp. 1980).
The Court of Appeals of Ohio expressed some doubt as to whether Mrs. Isaacs had been totally forthcoming in professing no knowledge of the whereabouts of her daughter, who had been linked to respondent’s criminal involvements and who, in Mrs. Isaacs’ words, “wants to make her own way, and forget all the unpleasantness that happened here, and prove something to herself and to us, and to think about her future and forget her past.” Tr. 195-196. See App. 5-6. These reservations about the candidness of Mrs. Isaacs’ testimony provide yet another reason why the State was not justified in relying solely on the Isaacs’ representations to establish Anita’s unavailability.