The court in California v. Green, 399 U.S. 149, 165-66, 90 S.Ct. 1930, 26 L.Ed.2d 489 (1970)stressed the unavailability requirement: This Court long ago held that admitting the prior testimony of an unavailable witness does not violate the Confrontation Clause. Mattox v. United States, 156 U.S. 237, 15 S.Ct. 337, 39 L.Ed. 409 (1895). That case involved testimony given at the defendant's first trial by a witness who had died by the time of the second trial, but we do not find the instant preliminary hearing significantly different from an actual trial to warrant distinguishing the two cases for purposes of the Confrontation Clause. Indeed, we indicated as much in Pointer v. Texas, 380 U.S. 400, 407, 85 S.Ct. 1065, 13 L.Ed.2d 923 (1965), where we noted that "the case before us would be quite a different one had Phillips' statement been taken at a full-fledged hearing at which petitioner had been represented by counsel who had been given a complete and adequate opportunity to cross-examine." and in Barber v. Page, 390 U.S. 719, 725-726, 88 S.Ct. 1318, 20 L.Ed.2d 255 (1968), although noting that the preliminary hearing is ordinarily a less searching exploration into the merits of a case than a trial, we recognized that "there may be some justification for holding that the opportunity for cross-examination of a witness at a preliminary hearing satisfies the demands of the confrontation clause where the witness is shown to be actually unavailable . . . ." In the present case respondent's counsel does not appear to have been significantly limited in any way in the scope or nature of his cross-examination of the witness Porter at the preliminary hearing. If Porter had died or was otherwise unavailable, the Confrontation Clause would not have been violated by admitting his testimony given at the preliminary hearing--the right of cross-examination then afforded provides substantial compliance with the purposes behind the confrontation requirement, as long as the declarant's inability to give live testimony is in no way the fault of the State. 399 U.S. at 165-66. Two years after Green, the Court in Mancusi v. Stubbs, 408 U.S. 204, 92 S.Ct. 2308, 33 L.Ed.2d 293 (1972), addressed a situation where the prior judicial proceeding was a previous trial. The witness in the Mancusi case moved out of the country after the first trial and therefore was unavailable for the retrial. Id. at 209. While not expressly stated in Mancusi, it appears the Court required a preliminary finding of unavailability prior to allowing the former trial testimony to be used at the retrial. The Court explained: The witness Holm, consistently with the requirement of the Confrontation Clause, could have been and was found by the trial court to be unavailable at the time of the second trial. There was, therefore, no constitutional error in permitting his prior-recorded testimony to be read to the jury at that trial, and no constitutional infirmity in the judgment of conviction resulting from that trial . . . .Id. at 216. The import of Green and Mancusi is that in both of those cases the "prior judicial proceeding" at issue involved full-scale cross-examination mirroring that in a trial. Indeed, the "prior judicial proceeding" in the Mancusi case was a former trial. The Green and Mancusi decisions linked an unavailability requirement to the use of the prior testimony, despite the former opportunity for full cross- examination, and thereby clarified the dicta in Pointer suggesting the contrary. It is in this context that the Roberts case was decided several years later.