concurring.
Although I agree in the result reached by the majority, I must express my disagreement with the majority’s resolution of the issue raised pertaining to the proffered testimony of co-participant Covil.
First, the majority assumes that the reason Covil was not called as a trial witness was because he was awaiting trial on murder charges stemming from the same incident, see, 488 Pa. at 408 n.6, 412 A.2d at 573 and second, that if he had been called he would have invoked his rights against self-incrimination guaranteed by the federal and state constitutions. These assumptions of such critical facts are completely unjustified. Moreover, even proceeding from these unfounded assumptions, it is my view that a witness who chooses to exercise the constitutional right against self-incrimination is not “unavailable” for the purposes of post conviction relief under section 3(c)(13) of the Post Conviction Hearing Act, Act of January 25, 1966, P.L. (1965) 1580, 19 P.S. § 1180-3(c)(13) (Supp.1979-80). See Commonwealth v. Sanabria, 487 Pa. 507, 410 A.2d 727 (Opinion in Support of Affirmance by Nix, J., joined by Larsen and Flaherty, JJ., filed February 1, 1980). Thus, under my view we would need to proceed no further before determining appellant’s claims to be without merit.
Instead of determining whether appellant’s contentions provide a basis for relief under section 3 of the PCHA, the majority considers these contentions in terms of after-discovered evidence, and ignores the fact that the present case is a collateral attack pursuant to the PCHA. After-discovered evidence may provide a basis for relief on direct appeal, see Pa.R.Crim.Pro. 1132(d), Commonwealth v. Valderrama, 479 Pa. 500, 388 A.2d 1042 (1978), but on collateral attack, a remedy may be obtained only where the claim fits within the provisions of section 3 of the PCHA. See Commonwealth v. Sheehan, 446 Pa. 35, 285 A.2d 465, 467 (1971) (the intent of the PCHA is “to promulgate an exclusive, well-defined procedure for the presentation of those grievances set forth in the Act”). Under section 3(c)(13) a person is *411eligible for relief only if his conviction or sentence resulted from “[t]he unavailability at the time of trial of exculpatory evidence that has subsequently become available and that would have affected the outcome of the trial if it had been introduced.
The Court’s reliance upon Commonwealth v. Dowd, 472 Pa. 296, 372 A.2d 705 (1977); Commonwealth v. Treftz, 465 Pa. 614, 351 A.2d 265 (1976), and Commonwealth v. Tervalon, 463 Pa. 581, 345 A.2d 671 (1975), is misplaced, in all three of these cases, this Court was presented with direct appeals of whether the defendant, after the verdict, had found evidence sufficient to justify a new trial. In such direct appeals the traditional test for “after-discovered evidence” is properly employed. In an action brought under the PCHA, however, we are compelled to employ the standards set forth in that statute, and may not substitute for those standards, the test applicable in a direct appeal.
As the majority indicates, the elements of the after-discovered evidence claim are: (a) the evidence must have been discovered after the trial, (b) must be such that it could not have been obtained at the trial in the exercise of reasonable diligence, and (c) must not be cumulative or merely impeach credibility, but rather, likely to compel a different result. Commonwealth v. Valderrama, 479 Pa. at 505, 388 A.2d at 1045. Whether the requirement of unavailability under section 3(c)(13) of the PCHA is coextensive with parts (a) and (b) of the after-discovered evidence rule is a question that has yet to be definitively answered by this Court. Compare Commonwealth v. Sanabria, supra, Opinion in Support of Affirmance, with Opinion in Support of Reversal. Today’s majority opinion has the effect of implicitly suggesting that the requirements of the two rules are the same. While I concede that in many cases the result may be the same regardless of which rubric is used, I do not believe that the distinction should be ignored without first making an express determination as to whether the two theories are in fact the same. An implicit assumption without first carefully assessing the legislative intention sought to be expressed in 3(c)(13) is in my judgment totally unacceptable.
*412My further disagreement with the majority’s resolution of this case stems from its misinterpretation of the third element of the after-discovered evidence rule. The majority concludes that the post conviction hearing court properly determined that the proffered evidence was not credible. In so doing, the majority has suggested that the third requirement of the after-discovered evidence rule (i. e., likely to compel a different result) extends beyond the nature of the testimony and empowers the court to prejudge the credibility of the proffered evidence. I do not believe that the after-discovered evidence rule was intended to transfer the function of determining credibility from the finder of fact to the court. It is my understanding that the third requirement under the rule was designed to limit relief to those instances where the after-discovered evidence goes directly to the question of guilt or innocence, and exclude testimony that would merely attack credibility or corroborate other evidence that had been previously submitted to the finder of fact.
The only instances where credibility is properly before a court faced with the question of after-discovered evidence is where the witness whose testimony is being offered has previously testified in a contradictory fashion. See, e. g., Commonwealth v. Anderson, 466 Pa. 339, 341-42, 353 A.2d 384 (1976); Commonwealth v. Riley, 458 Pa. 390, 326 A.2d 384 (1974); Commonwealth v. Coleman, 438 Pa. 373, 377, 264 A.2d 649 (1970); Commonwealth v. Baily, 250 Pa.Super. 402, 409-10, 378 A.2d 998 (1977). In those instances where the court is faced with a recantation, credibility is legitimately an issue in determining whether a prior verdict should be disturbed.1 In a case such as this, where there has been no *413prior inconsistent statement, attributed to the witness, and his testimony goes to the very heart of the question of the accused’s guilt or innocence, the court should not be given the right to decide whether, in its view, a jury would accept or reject the evidence.2
. In Commonwealth v. Osborn, 223 Pa.Super. 523, 524, 302 A.2d 395, 396 (1973), the Superior Court was faced with the recantation of testimony given by a co-defendant. In discussing such testimony, the court stated: “Since the affidavit of a Commonwealth witness who recants his testimony is extremely unreliable, the hearing court must deny relief where it is not satisfied that a recantation is true.”
Generally, recantation testimony is offered by an accomplice who no longer has any interest in telling the truth. There is an ever present danger that a co-defendant will be susceptible to urgings that *413he change his story to assist the cause of his co-defendant. This real possibility justifies the court’s consideration of credibility in these situations.
. An exception to this rule would be appropriate only where the proffered evidence is patently unbelievable.