concurring.
I concur in the result.
U.S. Supreme Court Justice Benjamin N. Cardozo, addressing the propriety of affording the state in a criminal trial with a right similar to that afforded the defendant, that is to secure a trial free from substantial legal error, observed:
What the answer would have to be if the state were permitted after a trial free from error to try the accused over again or to bring another case against him, we have no occasion to consider---- The state is not attempting to wear the accused out by a multitude of cases with accumulated trials. It asks no more than this, that the case against him shall go on until there shall be a trial free from the corrosion of substantial legal error.... This is not cruelty at all, nor even vexation in any immoderate degree. If the trial had been infected with error adverse to the accused, there might have been review at his instance, and as often as necessary to purge the vicious taint. A reciprocal privilege, subject at all times to the discretion of the presiding judge ... has now been granted to the state. There is here no seismic innovation. The edifice of justice stands, its symmetry, to many, greater than before.
Palko v. Connecticut, 302 U.S. 319, 328, 58 S.Ct. 149, 153, 82 L.Ed. 288 (1937) (citations omitted), overruled, Benton v. Maryland, 395 U.S. 784, 89 S.Ct. 2056, 23 L.Ed.2d 707 (1969); see also Commonwealth v. Bosurgi, 411 Pa. 56, 190 A.2d 304, 308 (1963) (“In our zeal to protect and preserve for the accused every constitutional right to which he is entitled we too often forget and neglect to preserve the rights of society which, too, are entitled to consideration.”). The underlying jurisprudential issue raised in this case is whether, where a post-acquittal appeal by the Commonwealth is prohibited by the constraints of double jeopardy — no matter how corroded by substantial error, to the detriment of the Commonwealth, *423the trial may have been — the Commonwealth should be afforded some degree of “symmetrical privilege” to seek to ensure, through the only timely appellate review available to it, that it and the people whom the prosecution represents receive a fair trial.
Under Pa.R.A.P. 311 and our decisional law, it is now settled that where it is Commonwealth evidence that has been excluded by pretrial order, an appeal will lie as of right, conditioned upon certification of the prosecutor as an officer of the Court that the exclusionary ruling effectively terminates or substantially handicaps the prosecution. The present appeal raises a more difficult question: should the Commonwealth ever be permitted to appeal as of right from a pretrial decision which would admit defense evidence, evidence which the Commonwealth believes is both inadmissible and will compromise society’s symmetrical right to a fair trial in a criminal matter? I agree with the Majority that a ruling admitting defense evidence differs in kind from a ruling which has the effect of diminishing or eliminating the Commonwealth’s case-in-chief. But, it seems to be indisputable that certain erroneous rulings on defense evidence can also be devastating to the Commonwealth’s right to a fair trial. Mr. Justice Eakin’s Dissenting Opinion cogently suggests some not-implausible scenarios where that result just might obtain: i.e., erroneous Rape Shield Act rulings or rulings permitting expert testimony on witness credibility. Permitting a pretrial Commonwealth appeal in such instances does not augur the prospect of the Commonwealth wearing the accused down through repeated trials or vexatious pretrial tactics; rather, it merely provides a limited symmetrical means to vindicate the Commonwealth’s right to a fair trial which, in turn, inures to the benefit of society as a whole. Trials are supposed to be fair inquiries into the truth based upon the prevailing law of the land: their results should not be pre-destined by arbitrarily-insulated and erroneous legal rulings.
The difficulty in the majority and dissenting postures is that each stakes out what amounts to an absolutist position on the question of the Commonwealth’s right to review. Thus, the *424Majority deems Rule 311(d) totally inapplicable, and would never permit the Commonwealth to appeal as of right in an instance involving admission of defense evidence. The Dissents, on the other hand, would always permit such appeals, so long as the Commonwealth provided a Rule 311(d) certification that the ruling on the defense evidence substantially handicapped the prosecution. As a matter of Rule 311 interpretation, there is rational support for each position. The Majority understandably cites the “under circumstances provided by law” qualifier, viewing this decision itself as that controlling circumstance, and also stresses the fact that Bosurgi and its progeny involve the suppression/exclusion of evidence paradigm. The Dissents, meanwhile, note that the actual language of Rule 311(d) is not restricted to situations involving suppression or exclusion of Commonwealth evidence and also cite to the importance, squarely acknowledged in the Bosurgi line of cases, of the fact that the Commonwealth, unlike the defendant, has no post-trial right of review.
These diametric positions are a reflection of the absolute language contained in Rule 311 itself: i.e., if the Rule applies, the Commonwealth’s certification alone is sufficient to perfect the Commonwealth’s right to appeal. See, e.g., Commonwealth v. Dugger, 506 Pa. 537, 486 A.2d 382, 386 (1985). But, the underlying assumption shared by the Majority and Dissents — that Rule 311 provides the only potential basis for a Commonwealth appeal as of right in this instance — may itself be unnecessary. The better approach would be to view this case in the manner in which the Bosurgi Court approached the issue of appellate jurisprudence presented to it: as a novel question requiring a fresh view that reasonably accommodates both the accused’s right to a speedy trial and the Commonwealth’s right to a fair one. The defense evidence posture of this case implicates concerns which, though related, are nevertheless distinct from the suppression/exclusion paradigm that led to the Bosurgi rule and, eventually, to Rule 311. The actual language devised in Bosurgi and imported into Rule 311 — referencing effective termination and substantial handi*425cap — is obviously in response to the circumstance of an exclusion of Commonwealth evidence.
But, as the Dissents properly recognize, the exclusion of Commonwealth evidence is not the only manner by which the Commonwealth may be denied a fair trial. When it is defense evidence that is at issue, “substantial handicap” to the Commonwealth is not so much implicated as the prospect that the Commonwealth will be unable to receive a fundamentally fair trial. There can be certain defense evidence whose impact may be devastating to the Commonwealth’s prospects of a just trial; indeed, that is precisely why our Rules require pre-trial disclosure of certain defenses and witnesses, thereby permitting the Commonwealth a fair opportunity to prepare. Pa. R.Crim.P. 573(C); see also Commonwealth v. Sartin, 561 Pa. 522, 751 A.2d 1140, 1146 (2000) (adverting to “the now discredited days of trial by ambush and surprise rather than the modern theory of open discovery and pre-trial announcement of defenses”).1
It is not an unusual circumstance for this Court to establish through decisional law an appropriate avenue of appealability in the absence of a governing or officially promulgated procedural rule. E.g. Commonwealth v. Morris, 565 Pa. 1, 771 A.2d 721, 730, n. 8 (2001) (noting that existing appellate rules did not provide for appeal of trial court order staying execution where trial court denied substantive relief and there was no pending appeal, and referring matter to Appellate Procedural Rules Committee to devise such a Rule); Commonwealth v. Brady, 510 Pa. 336, 508 A.2d 286, 291 (1986) (fashioning rule to govern pretrial appeals by accused on double jeopardy *426grounds; holding that such appeals are permissible unless trial court makes written finding that motion is frivolous). Certainly, the Bosurgi Court did not permit the absence of a then-existing appellate Rule to prevent it from fashioning one that was appropriate for the circumstances. In similar fashion, I would candidly recognize that Rule 311 was not intended to address the situation sub judice and I would proceed to analyze the issue with a fresh eye which accounts for the distinct concerns presented here.
Ultimately, I believe that the better rule in this situation is one which would recognize the Commonwealth’s right to appeal certain pre-trial decisions involving defense evidence, but which would require something different and greater than a Commonwealth certification of substantial handicap. The Rule should be aimed at addressing circumstances where there is a substantial showing that the pretrial ruling would likely implicate the Commonwealth’s right to a fundamentally fair trial. The procedural mechanism to accomplish such a screening of Commonwealth appeals could proceed as a preliminary determination by the appellate court that the issue presents a substantial question affecting the ability of the Commonwealth to obtain a fair trial; or by a trial court certification that the Commonwealth’s claim that the ruling substantially affected its ability to receive a fair trial is not frivolous. See Brady, 508 A.2d at 291. I offer these only as examples; I would refer the matter to the Appellate and Criminal Procedural Rules Committees for their input as to the standard which would best achieve the symmetrical edifice of justice so eloquently described by Justice Cardozo nearly three-quarters of a century ago.
Turning to this appeal, I concur in the mandate today because, in the absence of a governing rule, I am left with my own independent judgment as to whether denial of the Commonwealth’s right to appeal in this case presents a substantial prospect that it will be unable to receive a fair trial. I tend to agree with the Superior Court that the ruling below was an abuse of discretion as it would admit expert evidence that would invade the jury’s province of determining witness credi*427bility. However, I also note that such evidence is subject to impeachment and rebuttal, which should adequately protect the Commonwealth’s right to a fair trial. Moreover, quite frankly, the defense evidence on this record seems to me so implausible on its face (purporting to establish by expert opinion where appellant had focused his attention prior to colliding with the victim’s vehicle) that I doubt it would be very persuasive with a jury. Accordingly, in this circumstance I do not believe that the erroneous pretrial evidentiary ruling substantially compromised the Commonwealth’s ability to secure a fair trial.
. The Majority's suggestion lhat a recognition of any Commonwealth right to appeal in this instance would "likely” lead to a defense “reluctance” or “refusal” to disclose evidence required to be disclosed by Rule 573, Majority op. at 876, suggests a right or power of the defense which that Rule does not remotely contemplate. Disclosure of certain defense evidence under the Rule is mandatory; any defense “reluctance” or "refusal” properly risks sanction, including outright exclusion of the evidence. I do not share the Majority’s view that the defense bar is “likely” to engage in unethical conduct in violation of the Rule; and, even if I did, I do not agree that the prospect of unethical defense conduct is relevant to the Commonwealth's right to a fair trial.