OPINION OF THE COURT
FLAHERTY, Justice.On May 14,1980, Roderick Herman Frey was convicted of murder in the first degree in connection with the contract-murder of his wife. A verdict of death was returned by the jury pursuant to 42 Pa.C.S. § 9711(f). On appeal, the sentence of death was affirmed. Commonwealth v. Frey, 504 Pa. 428, 475 A.2d 700 (1984), cert. denied, 469 U.S. 963, *342105 S.Ct. 360, 83 L.Ed.2d 296 (1984). Subsequently, a motion for a new trial was denied, and, on appeal, the sentence was again affirmed. Commonwealth v. Frey, 512 Pa. 557, 517 A.2d 1265 (1986), cert. denied, 481 U.S. 1007, 107 S.Ct. 1633, 95 L.Ed.2d 206 (1987). A warrant for Frey’s execution was then issued by the Governor, following which Frey filed a petition for post-conviction relief. The petition and accompanying request for a stay of execution were denied by the court below. The present appeal ensued. On June 9,1988, this Court granted a stay of execution pending appeal.
The first contention raised by appellant is that statutory authority in this Commonwealth for inflicting the death penalty by means of electrocution is no longer valid. We do not agree. It is to be noted at the outset, however, that the validity of the sentence of death is not tied to the method of imposition. Commonwealth v. Terry, 513 Pa. 381, 408, 521 A.2d 398, 412 (1987), cert. denied, 482 U.S. 920, 107 S.Ct. 3198, 96 L.Ed.2d 685 (1987).
The legislature has designated electrocution as the method of execution to be employed in effectuating sentences of death. Act of June 19, 1913, No. 338, P.L. 528, 61 Pa.S. §§ 2121-2129 (hereinafter Act of 1913). The Act of 1913 sets forth a comprehensive procedure governing the execution process, beginning with the following provision:
Every person, his aiders, abettors and counsellors, hereafter convicted of the crime of murder of the first degree, shall be sentenced to suffer death in the manner herein provided, and not otherwise. Such punishment, in every case, must be inflicted by causing to pass through the body of the convict a current of electricity of intensity sufficient to cause death, and the application of such current must be continued until such convict is dead. The said punishment shall be inflicted by the warden or deputy warden of the Western Penitentiary, or by such person as the warden shall designate, and shall be inflicted in a *343building to be erected on the land owned by the Commonwealth____
61 Pa.S. § 2121.
Successive sections of the Act of 1913 prescribe transmittal of the trial transcript to the Governor, issuance of a warrant to proceed with the execution, confinement and visitation of the prisoner, observation of the execution, certification of the completed execution, postmortem examination and disposition of the body, and payment of expenses associated with the execution. 61 Pa.S. §§ 2122-2128. Finally, in 61 Pa.S. § 2129, there appears the following provision:
This act is intended to furnish a comprehensive and complete method of inflicting the death penalty. If any portion of this act shall be declared invalid or unconstitutional by the Supreme Court of Pennsylvania, the entire act shall thereupon be null and void.
Relying upon this provision, and asserting that the first clause in 61 Pa.S. § 2121, supra is a mandatory sentencing provision that this Court has declared unconstitutional, appellant claims that the Act of 1913 is null and void in its entirety. Appellant has failed to bring to our attention, however, any decision in which the Supreme Court of Pennsylvania has addressed any of the provisions of the Act of 1913 and declared them invalid or unconstitutional. Indeed, this Court has never rendered such a decision. Our opinion in Commonwealth v. Terry, 513 Pa. at 408, 521 A.2d at 412, insofar as it contained brief dictum indicating that the Act of 1913 contained a mandatory sentencing provision that had been declared unconstitutional, was lacking in accuracy.
This Court has vacated sentences of death and imposed sentences of life imprisonment in cases where death sentences were imposed under procedural statutes that were violative of the Eighth and Fourteenth Amendments. None of these cases involved the Act of 1913. Rather, most were decided under the Act of June 24, 1939, P.L. 872, § 701, as amended, 18 Pa.S. § 4701, a sentencing procedures statute which, although allowing imposition of sentences of either *344life imprisonment or death in connection with convictions for murder of the first degree, did not meet constitutional standards set forth in Furman v. Georgia, 408 U.S. 238, 92 S.Ct. 2726, 33 L.Ed.2d 346 (1972) (discretion of the sentencing authority must be adequately channeled to avoid arbitrary action). See Commonwealth v. Dobrolenski, 460 Pa. 630, 334 A.2d 268 (1975); Commonwealth v. Martin, 465 Pa. 134, 348 A.2d 391 (1975), cert. denied, 428 U.S. 923, 96 S.Ct. 3234, 49 L.Ed.2d 1226 (1976); Commonwealth v. Bradley, 449 Pa. 19, 295 A.2d 842 (1972); Commonwealth v. Ross, 449 Pa. 103, 296 A.2d 629 (1972); Commonwealth v. Sharpe, 449 Pa. 35, 296 A.2d 519 (1972). Others were decided under section 1311 of the Sentencing Code of 1974, 18 Pa.C.S. § 1311, which, though unconstitutional in itself, had been enacted in an effort to cure the defects in sentencing procedures illuminated by the decision in Furman, supra. Commonwealth v. Moody, 476 Pa. 223, 382 A.2d 442 (1977), cert. denied, 438 U.S. 914, 98 S.Ct. 3143, 57 L.Ed.2d 1160 (1978); Commonwealth v. Davis, 479 Pa. 274, 388 A.2d 324 (1978). See also Commonwealth v. McKenna, 476 Pa. 428, 433-37, 383 A.2d 174, 177-79 (1978) (history of legislative efforts to enact a constitutionally valid sentencing statute). At no time, however, has this Court declared any provision of the Act of 1913 invalid or unconstitutional.
It is clear, of course, that mandatory sentences of death do not meet constitutional standards. Woodson v. North Carolina, 428 U.S. 280, 96 S.Ct. 2978, 49 L.Ed.2d 944 (1976); Commonwealth v. Moody, 476 Pa. at 232-33, 382 A.2d at 446-47; Commonwealth v. Cross, 508 Pa. 322, 333-36, 496 A.2d 1144, 1150-52 (1985). If the language in 61 Pa.S. § 2121 were construed as a mandatory sentencing provision, and if it were deemed to be still in effect, we would have no alternative but to declare it unconstitutional.
However, as stated in Commonwealth v. Terry, supra, the current sentencing statute, 42 Pa.C.S. § 9711, was enacted to correct constitutional deficiencies in sentencing procedures. The constitutionality of 42 Pa.C.S. § 9711 has been upheld. Comonwealth v. Zettlemoyer, 500 Pa. 16, 454 *345A.2d 937 (1982), cert. denied, 461 U.S. 970, 103 S.Ct. 2444, 77 L.Ed.2d 1327 (1983). Appellant was sentenced in accordance with this statute, rather than under the Act of 1913. Indeed, the Act of 1913 has not been interpreted as a sentencing statute, but rather as a statute which merely defines the method to be utilized for inflicting the death penalty. Prior to the Act of 1913, death sentences were carried out by means of hanging rather than electrocution. As stated in Commonwealth v. Meyers, 290 Pa. 573, 585, 139 A. 374 (1927), “The Act of 1913 did nothing more than provide that, in cases where death was fixed as the penalty, the method of executing the sentence should be electrocution.” See also 61 Pa.S. § 2129, supra (“This act is intended to furnish a comprehensive and complete method of inflicting the death penalty.” (emphasis added)). Thus, we are not persuaded by appellant’s argument that the introductory language contained in the Act of 1913, to wit, the first clause of 61 Pa.S. § 2121, supra, insofar as it recites that every person convicted of murder of the first degree shall be sentenced to death, constitutes a mandatory sentencing provision. As discussed in Commonwealth v. Meyers, 290 Pa. at 584-85, 139 A. at 378-79, this language was merely a prefatory recitation of the penalties existing under another statute at the time the Act of 1913 was adopted.
However, even assuming arguendo that the language in question had been construed as a sentencing provision, we would have no occasion to now declare it unconstitutional, since it is no longer in effect. Subsequent sentencing statutes, e.g., 42 Pa.C.S. § 9711, have, by eliminating mandatory sentences of death, clearly supplanted the challenged provision. See 1 Pa.C.S. § 1936 (statute latest in enactment must prevail). In light of these statutory modifications, the Act of 1913 must be read as if amended to state: “Every person convicted of the crime of murder of the first degree, and sentenced to death thereon, shall be executed in the manner herein provided, and not otherwise.” This comports, too, with a presumption the legislature would not have enacted valid death penalty *346sentencing procedures, 42 Pa.C.S. § 9711, without having in place a method for carrying out sentences of death. 1 Pa.C.S. § 1922(1) (presumption legislature does not intend a result that is absurd, impossible of execution, or unreasonable). In short, the legislature has removed the challenged provision from operation prior to there being any occasion for this Court to address its validity. It cannot be said, therefore, that any portion of the Act of 1913 has been, or should be, declared unconstitutional.1
The next contention raised by appellant is that the jury instructions and verdict slip employed in the penalty phase of trial must be deemed deficient in light of the recent decision of the Supreme Court of the United States in Mills v. Maryland, 486 U.S. —, 108 S.Ct. 1860, 100 L.Ed.2d 384 (1988). This contention is without merit. In Mills, the jury instructions and verdict slip utilized at trial contained specific elements of language and form that created a substantial risk of jurors being misled to believe that, unless they agreed unanimously on the existence of any given mitigating circumstance, the circumstance could not be taken into account by any of the jurors during deliberations. 486 U.S. at —, 108 S.Ct. at 1870, 100 L.Ed.2d at 400. The Mills decision is simply inapposite to the present case, however, for the jury instructions and verdict slip used in appellant’s trial did not contain language similar to that found in Mills.
The present instructions did not express a need for unanimity in determining the existence of mitigating circumstances. (N.T. 1388-91). Nor did the form of the verdict slip infer a need for such unanimity.2 The jury instructions *347and verdict slip closely followed language in the sentencing statute stating that a unanimous verdict is necessary as to the ultimate decision to impose a sentence of death, 42 Pa.C.S. § 9711(c)(l)(v), but did not state or infer a requirement that any given mitigating circumstance must be unanimously recognized before it can be weighed against aggravating circumstances in reaching a verdict. See 42 Pa.C.S. § 9711(c)(l)(iv) (“[T]he verdict must be a sentence of death if the jury unanimously finds at least one aggravating circumstance specified in subsection (d) and no mitigating circumstance or if the jury unanimously finds one or more aggravating circumstances which outweigh any mitigating circumstances.”). Thus, individual jurors were free to weigh whatever mitigating circumstances they perceived, *348regardless of whether other jurors agreed that those circumstances were established by the evidence. The perceptions of even one juror, alone, with regard to mitigating circumstances, would be sufficient to deny the unanimity required for a sentence of death.
Many of the remaining issues raised in this appeal warrant only brief discussion, for they are clearly lacking in substance. Inasmuch as this is the third time that this Court has been called upon to address appellant’s sentence of death on appeal, issues having greater substance have, in the main, been resolved in the earlier appeals.
Appellant contends that the verdict slip employed in the penalty phase of trial was defective in that it did not require the jury to list any mitigating circumstances found. It is already well settled, however, that there is no requirement that mitigating circumstances be listed. Commonwealth v. Carpenter, 511 Pa. 429, 444, 515 A.2d 531, 539 (1986).
Appellant asserts that no instruction was given by the court indicating that a sentence of life imprisonment would be imposed if the jury failed to reach a unanimous verdict. This assertion is plainly contradicted by the record. (N.T. 1391).
It is further claimed by appellant that our decision in one of his earlier appeals, Commonwealth v. Frey, 504 Pa. at 440-41, 475 A.2d at 706, wherein we held that the fact that appellant was 42 years of age when he committed this crime could not in itself be regarded as a mitigating circumstance, unconstitutionally prevented the jury from considering factors such as “mid-life crisis,” “marital discord and tension,” and appellant’s record of having “lived 42 years without being convicted of any criminal offense.” This claim is patently lacking in basis.
Appellant was permitted to introduce evidence of his age at the penalty hearing, and the jury was instructed that the “youth or advanced age” of the defendant could be considered as a mitigating circumstance. The claim of error *349addressed in his earlier appeal involved a challenge to the court’s instruction that the jury could consider the “youth or advanced age” of the defendant, as opposed to simply the defendant’s “age.” We held, in essence, that there is nothing inherently mitigating about the age of 42 that would have rendered the instruction inadequate. It follows, therefore, that the jury was not unconstitutionally restricted in its consideration of mitigating factors. Evidence, to the extent any was introduced, relating to factors recited above such as emotional crisis, marital disharmony, and lack of prior criminal convictions would plainly have been subject to full consideration as elements of the other mitigating circumstances set forth in the jury instructions. See 42 Pa.C.S. § 9711(e)(2), (3), (5) (addressing extreme mental and emotional factors); 42 Pa.C.S. § 9711(e)(8) (“Any other evidence of mitigation concerning the character and record of the defendant and the circumstances of his offense.”); 42 Pa.C.S. § 9711(e)(1) (lack of significant history of prior criminal convictions).
Next, appellant raises a group of issues consisting of a plethora of assertions of trial counsel’s ineffectiveness. Many of these are restatements of matters addressed in earlier appeals and warrant little further comment. Others consist of allegations that omissions occurred in the presentation of potentially mitigating evidence. Examination of the record reveals, however, that counsel made a competent showing of such mitigating evidence as was available, including the testimony of appellant and testimony of character witnesses.
The allegedly omitted evidence can be classified generally as insignificant, irrelevant, or cumulative. For example, it is claimed that evidence should have been introduced that appellant was a member of the 4H Club and the Lions Club. In view of the seriousness of this crime and the extent of other evidence of character and record presented for the jury’s consideration, it is inconceivable that appellant’s club memberships could have affected his sentence. Similarly, it is asserted that counsel failed to present evidence that one *350of appellant’s children had been killed in an automobile accident nearly two years before the present murder, yet examination of the record reveals that this evidence was indeed introduced during the guilt determination phase of trial. (N.T. 1046, 1102). During the penalty phase of trial, counsel moved for admission of all of the defense evidence from the guilt phase. Evidence regarding the death of appellant’s child, as well as additional evidence pertaining to appellant’s character, reputation, and marital relationship thereby came before the jury for consideration. With regard to his marital relationship, appellant claims evidence in mitigation could have been offered that his wife, the victim in this murder, had been having extramarital affairs. Such evidence would have been of little worth, since there was already evidence in the record that appellant and his wife suffered serious marital problems, and, further, the evidence would have appeared preposterous to the jury and would have undermined appellant’s credibility since appellant himself had testified during the guilt determination phase that he was certain that his wife never engaged in extramarital affairs.
It is also claimed that the jury should have been informed that one of appellant’s co-conspirators, who fired the fatal shot in this murder, received only a sentence of life imprisonment. Sentencing is a highly individualized matter, and we have already ruled that the cases against appellant’s co-conspirators are not similar to appellant’s case for purposes of proportionality review. Commonwealth v. Frey, 504 Pa. at 444-45, 475 A.2d at 708. The sentence received by a co-conspirator is not a mitigating circumstance as to appellant’s role in the crime.
Next, appellant claims his defense was prejudiced by counsel’s failure to present the testimony of a certain co-conspirator. This Court has already considered the testimony in question and determined that it would not have affected the verdict. Commonwealth v. Frey, 512 Pa. at 565-567, 517 A.2d at 1268-1270.
*351Appellant further asserts that counsel, during his closing argument, misstated the number of mitigating circumstances that might be found in this case. Counsel did, in fact, comment with regard to the number of such circumstances that that there “may be two, or perhaps only one.” Yet counsel then proceeded to make an argument encompassing a broad range of factors including references to appellant’s age, character, background, record, and the possibility that appellant’s actions were the result of duress or coercion. During instructions to the jury on sentencing matters, the court fully informed the jury of the complete range of mitigating circumstances that might be found in this case. Appellant was not prejudiced by counsel’s comment.
Counsel’s effectiveness is also challenged through cursory arguments that voir dire was inadequate and that inflammatory details of the murder were admitted without objection. We have examined these claims and find no basis for relief.
It is also claimed that counsel should have objected when the prosecutor allegedly stated during closing arguments at the guilt determination phase of trial that two of appellant’s co-conspirators were not called to testify because they would have invoked the Fifth Amendment. Examination of the record reveals that this claim is without merit. The prosecutor did not say that the co-conspirators would have invoked the Fifth Amendment, but rather stated that there were a number of reasons for his reluctance to call the co-conspirators to the stand, and that just one of those reasons was the possibility that they might assert their Fifth Amendment rights. Further, the prosecutor’s comment was merely a response to defense counsel’s closing argument in which it was inferred that the prosecution had an obligation to produce the co-conspirators’ testimony. Significantly, too, defense counsel’s closing argument expressly informed the jury that the co-conspirators might have asserted their rights to remain silent if they had been called by the prosecution as witnesses. Thus, the prosecu*352tor’s comment was a mere repetition of information that defense counsel had already disclosed to the jury; hence, there was no basis for objection.
The final issue presented for our review concerns the admissibility of testimony given by a prosecution witness, Sharon Bowers, at the penalty hearing. The fact that Bowers had knowledge pertinent to this case was not discovered by investigating authorities until after the close of the prosecution’s case at the guilt determination phase of trial; hence, her testimony was offered only at the penalty hearing. Bowers testified that she became acquainted with appellant at her place of employment and stated that appellant often engaged her in conversations about his marital problems. She further testified that during one of these conversations, approximately six months before the present murder, appellant expressed a desire to murder his wife:
One of the times Rod [appellant] was complaining about Barb [his wife], I remember that he made the remark that he said I would kill the son of a b.... if I knew I could get away with it, and it really surprised me that he said it and, you know, I stopped what I was doing, because we were both always working, you know, back there at the same time. I said oh, come on, Rod, you don’t mean that. And he said yes, I do. He said then she couldn’t enjoy her money, or it was one of the times he was complaining about financial problems they were having that he made the remark.
It is argued that this testimony should not have been introduced, in that it was assertedly not pertinent to proof of any of the aggravating circumstances enumerated in the sentencing statute. See 42 Pa.C.S. § 9711(d). The record reveals, however, that the court allowed admission of this testimony on grounds it tended to disprove a mitigating circumstance claimed by the defense throughout trial, to wit, that appellant had been coerced and influenced by a co-conspirator. Clearly, the testimony in question did show appellant’s uncoerced desire, even months before the mur*353der took place, to end the life of his wife, the testimony was properly admitted. For this reason,
Judgment of sentence affirmed.
NIX, C.J., files a concurring opinion. LARSEN, J., joins the majority opinion and files a concurring opinion which is joined by PAPADAKOS, J.. In view of this determination, we need not address the Commonwealth’s contention that the non-severability provision set forth in 61 P.S. § 2129, supra was later repealed by statutory construction legislation, 46 P.S. § 555 and 1 Pa.C.S. § 1925.
. The following is a reproduction of the verdict slip returned by the jury at the penalty hearing:
*347[[Image here]]