concurring.
I join the majority’s holding and reasoning with regard to claims 1, 2, and 8, concur in the overall result of the majority decision, and write to the following points.
First, I have reservations similar to those expressed by Mr. Chief Justice Cappy concerning the majority’s discussion of waiver. The majority finds fault with the state of Appellant’s brief filed in this Court, since issues are framed and developed largely from the standpoint of underlying claims that are plainly waived because they were not raised in the trial court. See Majority Opinion at 693-95, 910 A.2d at 678-80. Moreover, the only potentially available claims (those of ineffective assistance of counsel) are addressed in the brief primarily via an umbrella, introductory statement and/or in a tag-on fashion at the conclusion of each individual claim asserted. However, the majority indicates that it will review the claims, because the law concerning the development of certain ineffectiveness claims was not clear at the time that Appellant filed his petition for post-conviction relief. See id. at 695, 910 A.2d at 679-80. Since the majority does not take issue with Appellant’s claims in terms of the pleadings, I do not believe that its reasoning follows. Here, the flaw that is recognized is in briefs that were filed after the jurisprudence concerning ap*714pellate briefing of ineffectiveness claims was definitively clarified in Commonwealth v. McGill, 574 Pa. 574, 832 A.2d 1014 (2003).1
Certainly, in fight of the interests at stake, I have been a proponent of a fair degree of leeway in terms of the application of the waiver doctrine to both pleadings and briefs. See, e.g., Commonwealth v. Rivers, 567 Pa. 239, 266-70, 786 A.2d 923, 939-42 (2001) (Saylor, J., dissenting).2 But differences among Justices concerning the appropriate degree of latitude had resulted in many divided decisions, of which Rivers is a prime example. Those differences were resolved in McGill, wherein various Justices compromised their positions in favor of a single, uniform approach.
Having traveled this route once, I have no wish to repeat it. Thus, I believe that capital counsel should be specifically admonished that, if they wish for their clients’ claims to be considered as layered or derivative claims in any post-McGill brief, they must frame, structure, and develop them as such, per McGill. Under McGill, the umbrella and/or tag-on techniques are clearly unacceptable as methods for raising a derivative claim.3
With respect to briefs filed after the issuance of this opinion, I personally will no longer take up the cause for leeway *715exceeding that available under McGill, as the Court has now spoken very clearly, and the debate concerning briefs such as the present one has consumed far too many of this Court’s limited resources and is over. I also believe that there is too great a chance that the developing practice on the part of some attorneys of ignoring McGill in the application is tactical.
Next, I respectfully differ with the majority’s rationale concerning Claim 3 (juror impartiality). See Majority Opinion at 703-04, 910 A.2d at 684-85. From my perspective, the outcome would be better framed in terms of a failure to establish prejudice relative to the ineffectiveness claim attaching to the failure to raise the issue on direct appeal, as it would be my position that trial counsel should have been permitted to engage in additional voir dire questioning given the existence of a prior business relationship between the juror and the district attorney. But cf. Commonwealth v. Ellison, 588 Pa. 1, 902 A.2d 419 (2006).
Regarding Claim 4 (lack of Simmons instruction), see Majority Opinion at 704-05, 910 A.2d at 685, it would have been my position that the matter should be decided under the standard articulated in Kelly v. South Carolina, 534 U.S. 246, 122 S.Ct. 726, 151 L.Ed.2d 670 (2002). See Commonwealth v. Spotz, 587 Pa. 1, 109-113, 896 A.2d 1191, 1257-58 (2006) (Saylor, J., concurring and dissenting). However, I recognize that the Court determined in Spotz that Kelly established a new rule of law which is not to be retroactively applied to cases tried prior to its issuance. See Spotz, 587 Pa. at 86-87, 896 A.2d at 1242-46. Further, upon review of the record, it appears to me that the district attorney proceeded with a fair amount of restraint in his closing argumentation, focusing closely on the statutorily-enumerated aggravating circumstances, such that it is at least arguable that a Simmons instruction would not be due under Kelly in any event.
As to Claim 5 (advice of counsel), see Majority Opinion at 705-07, 910 A.2d at 685-87, to the extent that counsel’s advice was that testimony by Appellant about life-history mitigation would “quite probably” permit cross-examination concerning *716the circumstances of the offense, I believe that such guidance was inapt. In this regard, I agree with the observation of the United States Court of Appeals for the Third Circuit that penalty-phase testimony about childhood family background “[does] not bear even a tangential relationship to the substance of the charges against [the defendant].” Lesko v. Lehman, 925 F.2d 1527, (3d Cir.1991); cf. Commonwealth v. Hughes, 581 Pa. 274, 333-34 & n. 40, 865 A.2d 761, 796-97 & n. 40 (2004) (developing that the appropriate scope of cross-examination and rebuttal have always been defined according to the evidence they are designed to rebut).4 I join the majority’s decision to affirm the denial of relief on this claim because Appellant has not made a requisite showing of prejudice. In this regard, while Appellant asserts in his brief that he would have testified as to life-history mitigation had he not been erroneously advised by counsel, he offered no proof to this effect at his post-conviction evidentiary hearing (at which he did not testify), nor did he initially furnish an evidentiary proffer that would have implicated a hearing on the prejudice question.5 Absent such proof credited by a factfinder, I find there to be an insufficient basis to support an award of post-conviction relief on this claim.
. I read McGill as subsuming the appropriate methodology for raising claims of both appellate and trial counsel in appellate briefing. The clarification occurred in the former regard; as to the latter, McGill explained that there was no prevailing dispute.
. I also understand the derivative nature of ineffectiveness claims and the corresponding need to develop the underlying claim as part of the analysis. The problem has arisen, however, that various counsel have emphasized the underlying claim to the near exclusion of any substantive development of the essential ineffectiveness overlay, thus hampering appropriate appellate review of the only potentially available claim.
. If counsel feel the need to state waived, underlying claims outright for some purpose or purposes connected with federal habeas corpus review, this function would be more appropriately relegated to the umbrella and/or tag-on approach than would the development of the only claims that remain for this Court's review under McGill (i.e., the derivative claims). Counsel are certainly also free to state the underlying claim in the alternative if there is a bona fide belief that they are not waived under this Court’s present jurisprudence, but this does not excuse a correct development of a derivative claim per McGill if merits review on the derivative claim is also sought.
. The majority’s explication of Lesko, i.e., that it stands for the proposition that a defendant cannot claim a Fifth Amendment privilege at the penalty phase relative to matters related to credibility or the subject matter of his testimony, see Majority Opinion at 707, 910 A.2d at 686, is certainly correct as far as it goes. But the majority does not recognize the salient point for which Appellant references Lesko, namely, that the circumstances of the offense charged does not bear a sufficient relationship to credibility or life-histoiy-type mitigation testimony to support a waiver. See Lesko, 925 F.2d at 1543 ("We do not believe that Lesko's limited testimony constitutes a waiver of his right ... to be free from prosecutorial comment about his failure to testify about the merits of the prosecution’s case.”).
. Indeed, trial counsel's post-conviction testimony indicated that Appellant was substantially uncooperative as concerned the development of mitigation evidence for the penalty phase of trial.