The opinion of the Court was delivered by
PORITZ, C.J.
This case comes to us on the Public Defender’s petition for post-conviction relief over the objection of the defendant, John Martini, Sr., whose conviction of murder and sentence of death have been [255]*255upheld by this Court. The gravamen of the Public Defender’s petition is that the failure to present certain mitigating evidence at defendant’s penalty-phase trial “constituted ineffective assistance of counsel and otherwise violated defendant’s constitutional rights.” State v. Martini 148 N.J. 453, 454, 690 A.2d 603 (1997) (Martini TV). Because this claim bears directly on the “reliability and integrity” of the jury’s decision to impose death, we permitted the petition to go forward despite Martini’s objection and remanded for further proceedings. We directed the appointment of standby counsel to represent Martini and required the proceedings below to be conducted in camera in furtherance of defendant’s interest in maintaining the confidentiality of evidence the Public Defender wished to present to the trial court.
Today, we hold that in this case counsel’s failure to discover and put forward evidence that contains both mitigating and damaging elements does not constitute ineffective assistance of counsel. Because we do not find merit in the Public Defender’s other claims, we affirm the trial court’s decision to deny post-conviction relief.
I
FACTS AND PROCEDURAL HISTORY
In 1990, a jury convicted Martini of the kidnapping murder of Irving Flax, a Fair Lawn business executive. The evidence at trial established that Martini and codefendant Therese Afdahl abducted Flax and demanded ransom money from his wife. Although the money was paid, Martini nevertheless shot Flax three times in the back of the head. The jury found that Martini killed Flax to prevent him from identifying defendant.
During the trial Martini did not dispute the kidnapping or that he had fired the three fatal shots. Instead, defendant asserted that his cocaine addiction diminished his capacity such that the murder was not committed purposely or knowingly. The jury rejected his claim at both the guilt and penalty-phase trials, [256]*256finding at the conclusion of the penalty phase that the aggravating factors, taken together or individually, outweighed the mitigating factors. The trial judge thereafter sentenced Martini to death.
Defendant’s conviction and death sentence were upheld by this Court on direct appeal, State v. Martini, 131 N.J. 176, 619 A.2d 1208 (1993) (Martini I), and on proportionality review, State v. Martini, 139 N.J. 3, 651 A.2d 949 (1994) (Martini II). After the United States Supreme Court denied Martini’s petition for certiorari on October 2, 1995, 516 U.S. 875, 116 S.Ct. 203, 133 L.Ed.2d 137 (1995), the Law Division issued a warrant scheduling defendant’s execution for November 15,1995. On October 30,1995, the Public Defender sought post-conviction relief (“PCR”) and a stay of execution on defendant’s behalf, even though Martini said that he did not wish to file any further appeals. In response, the trial court entered a stay and appointed independent counsel to represent Martini. The court also appointed a psychiatrist to conduct an examination of defendant to determine whether he was competent to waive PCR proceedings. Following a two-day hearing the court concluded that Martini was competent, and that the Public Defender could not pursue PCR on Martini’s behalf without his consent. The stay of execution was continued pending review by this Court.
We held oral arguments on an expedited schedule. State v. Martini, 144 N.J. 603, 606, 677 A.2d 1106 (1996) (Martini III). We agreed with the trial court that the psychiatric evidence demonstrated Martini’s competence to make the waiver decision and that he “ha[d] voluntarily expressed a desire to prosecute no further appeals.” Id. at 617, 677 A.2d 1106. We explained, however, that the “ ‘State and its citizens have an overwhelming interest in insuring that there is no mistake in the imposition of the death penalty.’ ” Ibid, (quoting State v. Koedatich, 112 N.J. 225, 332, 548 A.2d 939 (1988) (Koedatich II), cert. denied, 488 U.S. 1017, 109 S.Ct. 813, 102 L.Ed.2d 803 (1989)). Respect for Martini’s choice could not take precedence over the paramount concern for “the reliability and integrity of a death sentencing decision.” Id. [257]*257at 605, 677 A.2d 1106. Accordingly, we remanded the matter for a PCR hearing consonant with our decision and focused on three issues that were not capable of review on defendant’s initial appeal:
(1) a defense based on certain undisclosed information that has been imparted to the Public Defender and presumably was not disclosed to the jury below; (2) a new constitutional principle announced by the Supreme Court after Martini’s trial in Simmons v. South Carolina, 512 U.S. 154, 114 S.Ct. 2187, 129 L.Ed.2d 133 (1994); and (3) evidence disclosed after Martini’s conviction that suggests that New Jersey’s death penalty system may be constitutionally flawed because of systematic discrimination against blacks and other minorities.
[Id. at 610-11, 677 A.2d 1106.]
On remand, the Public Defender attempted to present materials Martini considered confidential, claiming that the information contained therein constituted mitigating evidence erroneously omitted at the penalty-phase trial. As Martini expressed his continuing desire that this evidence remain confidential, the court conducted an in camera inspection of the Public Defender’s submission and ruled that Martini’s interest in maintaining the confidentiality of the submitted materials prevented their use in the PCR proceeding. The Public Defender sought leave to appeal the court’s decision, which we granted.
On reviewing the record and written arguments of counsel, this Court vacated the trial court’s order and again remanded the matter to permit the judge to “reconsider the issue of the omission of mitigating evidence from defendant’s penalty-phase trial.” Martini IV, supra, 148 N.J. at 453, 690 A.2d 603. We directed the lower court to determine:
1. Whether the evidence was mitigating;
2. If the evidence was mitigating, whether defense counsel’s failure to obtain the evidence constituted ineffective assistance of counsel or whether the omission of the evidence constituted a manifest injustice and a violation of defendant’s constitutional rights, entitling defendant to poskeonviction relief;
3. If defendant is entitled to post-conviction relief because of the failure to obtain or the omission of the evidence, whether defendant has an interest in preserving the confidentiality of the evidence;
4. If defendant has such a confidentiality interest, whether that interest can be protected in a penalty-phase proceeding by imposing conditions on the admission of the evidence, such as in camera proceedings, redaction of information, or the [258]*258presentation of the evidence through summarization or paraphrasing in a form that will eliminate the concerns for confidentiality; and
5. If the evidence can he used subject to such conditions, whether the failure to use the evidence at the penalty-phase proceeding of defendant constitutes ineffective assistance of counsel or a manifest injustice and a violation of defendant’s constitutional rights, entitling defendant to post-conviction relief____
[Id at 454, 690 A.2d 603.]
Lastly, we ordered the “hearing on remand [to] be conducted in camera, with the State and defendant being provided with all of the evidence at issue ... subject to its absolute confidentiality and strict non-disclosure.” Ibid.
Over the course of one year and one week, the trial judge heard testimony from Martini’s original trial counsel (who had withdrawn from the ease prior to trial), Martini’s actual trial counsel, a member of the Bergen County Prosecutor’s Homicide Squad (who initially investigated the Flax murder), and other witnesses. After hearing the testimony, reviewing all of the confidential evidence and listening to argument, the court determined that the evidence was not mitigating.
The court found that the testimony of Martini’s trial counsel and the Public Defender first assigned to his case established that none of those attorneys would have used the alleged mitigating evidence in Martini’s penalty-phase trial. To the contrary, trial counsel believed there was a substantial downside to the presentation of this evidence that outweighed any mitigating factors, and the Public Defender at that time saw the evidence as both “possibly good” and “not so hot.” From this, the court concluded that the evidence “would [not] have had a significant impact on [the jury’s] deliberations in that it [would not] have changed any one of [the juror’s] minds[.]” Because the trial judge found that the Public Defender’s evidence was not mitigating, counsel’s failure to obtain it was not ineffective assistance of counsel. Similarly, the potentially damaging effect of the evidence eliminated the possibility that its omission constituted a manifest injustice to Martini.
[259]*259In reaching this conclusion, the judge refused to allow two experts to testify on the mitigation value of the evidence. The Public Defender sought to introduce the testimony of mitigation specialists who would have described how the evidence could have provided a construct for a favorable social history of Martini. The judge determined that he did not need the aid of expert opinion because, as the trial judge in the murder and penalty-phase trials, he had acquired an understanding of the case that he was able to use in his evaluation of the evidence now proffered by the Public Defender. He further declined to admit the experts’ reports, specifically holding that one of the reports was inadmissible because it was based in part on privileged communications between the expert and Martini.
Although the judge found that defendant’s tidal attorneys were not ineffective, he nonetheless answered the question “whether defendant has an interest in preserving the confidentiality of the evidence.” The judge concluded that even if the evidence had some mitigating value, that minimal value was outweighed by Martini’s substantial interest in maintaining the confidentiality of the information. He explained that if the information is presented at a new penalty-phase trial, criminal defendants will learn that they cannot share confidences with their attorneys without risking exposure at some later date. In the court’s view, even though the evidence sought to be admitted was not revealed by the client, the effects of using it could be devastating to the attorney-client relationship. Because the judge concluded that the jury decision to impose the death penalty was reliable, defendant’s interest in confidentiality tipped the scale against a new penalty trial. Moreover, in the judge’s opinion Martini’s confidentiality interest could not be adequately preserved in a new trial, even through “in camera proceedings, redaction of information, or the presentation of the evidence through summarization or paraphrasing____” Martini IV, supra, 148 N.J. at 454, 690 A.2d 603.
After discussing the specific questions posed in Martini IV, the judge considered the additional points raised in the PCR petition [260]*260not related to the ineffective assistance of counsel claim. The Public Defender alleged that the State committed a Brady violation by failing to disclose the confidential information to the defense prior to Martini’s murder trial. See Brady v. Maryland, 373 U.S. 83, 87, 83 S.Ct. 1194, 1196-97, 10 L.Ed.2d 215, 218 (1963) (“[Suppression by the prosecution of evidence favorable to an accused ... violates due process where the evidence is material either to guilt or to punishment....”). The judge found this claim to be without merit. He concluded that the State did not have knowledge of the evidence at the time and, therefore, could not be obligated to release it to defendant. Further, even if the prosecutors had imputed knowledge, there was no Brady violation because the defendant himself possessed the information and chose not to share it with his attorneys.
The court dismissed the claim that Martini’s trial counsel were ineffective in failing to discover and present to the jury “burned screens” found in defendant’s hotel room after he was arrested. The screens were overlooked by Martini’s attorneys among the other evidence they reviewed before trial. Because the screens could have been used as additional evidence of defendant’s cocaine use, the Public Defender argued that they would have strengthened Martini’s diminished capacity defense. The court found that the evidence was cumulative and that it would not have altered the jury’s decision to reject this defense.
The court also ruled that the failure to instruct the jury that Martini would be subject to a consecutive fifteen-year parole ineligibility period for the kidnapping offense did not deprive the defendant of his due process right to a reliable sentencing proceeding. On this point, the judge pointed out “that this jury knew, based on all the testimony ... as to Mr. Martini’s age, his health[,] that certainly he would not be eligible for parole until he was 90 years old.” The judge held that if there was error in these circumstances it was not harmful.
Finally, the court briefly considered the Public Defender’s allegations that the death penalty is administered in a racially dis[261]*261criminatory manner; that imposition of the death penalty is prohibited by international law; and that the cumulative effect of the errors at Martini’s trial required a new penalty-phase proceeding. These claims were either dismissed or reserved to this Court (i.e., the racial bias claim). Accordingly, the Public Defender’s PCR petition was denied.
The Public Defender appeals the court’s determinations on all of the claims raised in the PCR petition. Martini’s special counsel requests that we affirm the decision below.
II
LEGAL CLAIMS
A. Is the Evidence Mitigating?1
The Public Defender asks us to set aside Martini’s death sentence because the failure to present certain mitigating evidence at defendant’s penalty-phase trial constituted ineffective assistance of counsel. This claim requires us to consider first whether the evidence is mitigating, a characterization vigorously contested both by the Bergen County Prosecutor and by Martini himself. Based on our review of the materials submitted by the Public Defender and the testimony at the hearing below, we conclude that the evidence presents a troubling picture that has some mitigation value mixed with a substantial downside potential. In effect, the usefulness of the evidence as mitigation is seriously undermined by its unfavorable aspects.
We recognize, also, that the evidence if used would have opened the door to damaging rebuttal evidence by the State. In a [262]*262penalty-phase trial, the State is entitled to impeach mitigation testimony with relevant evidence of a defendant’s past conduct, subject to an instruction that the evidence is admissible only for the limited purpose of rebutting mitigating factors and cannot be used to add to the weight assigned by the jury to the aggravating factors. State v. Rose, 112 N.J. 454, 503-08, 548 A.2d 1058 (1988); see also State v. Bey, 129 N.J. 557, 610, 610 A.2d 814 (1992) (Bey III), cert. denied, 513 U.S. 1164, 115 S.Ct. 1131, 130 L.Ed.2d 1093 (1995); State v. McDougald, 120 N.J. 523, 574, 577 A.2d 419 (1990). Even with a limiting instruction, in this ease the presentation of evidence of limited mitigating value would have opened the door to powerful countervailing testimony that could have swayed the jury against defendant. See State v. Morton, 155 N.J. 383, 431-33, 715 A.2d 228 (1998) (recognizing defense counsel not ineffective for failing to present mitigating evidence where evidence had potential to harm defendant’s mitigation case); State v. Marshall, 148 N.J. 89, 256, 690 A.2d 1 (1997) (Marshall III) (denying claim of ineffective assistance of counsel involving omission of “evidence that, although possibly beneficial to defendant, posed the clear risk of an adverse jury reaction”).
In reaching this conclusion, we are mindful that the omitted evidence has been separated into two sets by the Public Defender who argues that only the first is admissible. Specifically, the Public Defender claims that she should not have been ordered by the PCR court to serve the second set of material on the prosecution. She maintains that this set contains inculpatory information that would not have been used at trial, and thus is not discoverable under the principles of State v. Williams, 80 N.J. 472, 404 A.2d 34 (1979), and State v. Mingo, 77 N.J. 576, 392 A.2d 590 (1978). We are convinced that the first set is sufficiently injurious to Martini such that it too has only marginal mitigating value. For this reason, we need not reach a decision on the admissibility of the second set.2
[263]*263In evaluating the nature of this evidence we have independently reviewed two expert reports submitted by the Public Defender for the purpose of showing how the evidence could have been used to construct a favorable social history of Martini at his penalty-phase trial. The trial judge refused to allow the experts to testify or to admit their reports at the PCR hearing. We find that the reports are cumulative and add little to the Public Defender’s arguments. Because the reports reflect the experts’ anticipated testimony, and because expert testimony is only admissible if it “will assist the trier of fact to understand the evidence or determine a fact in issue,” N.J.R.E. 702; see also State v. Kelly, 97 N.J. 178, 208, 478 A.2d 364 (1984), we cannot say the trial court abused its discretion in excluding the experts or the reports. In this ease, there was ample testimony at the PCR hearing from Martini’s prior counsel and others about the possible value of the proffered evidence in a penalty-phase trial.
B. Ineffective Assistance of Counsel
In Lockett v. Ohio, the United States Supreme Court held that a defendant may not be precluded from presenting “as a mitigating factor, any aspect of [his or her] character or record ... as a basis for a sentence less than death.” 438 U.S. 586, 604, 98 S.Ct. 2954, 2964-65, 57 L.Ed.2d 973, 990 (1978); see also State [264]*264v. Bey, 112 N.J. 123, 156, 548 A.2d 887 (1988) (Bey II) (“[A] state statute may not preclude the jury from considering any relevant mitigating evidence pertaining to any aspect of defendant’s character.”). Our concern for “ ‘a reliable penalty determination’ ” has persuaded us that “a defendant in a capital case [may not] execute even a knowing and voluntary waiver of his right to present mitigating evidence during the penalty phase.” Koedatich II, supra, 112 N.J. at 330, 548 A.2d 939 (quoting People v. Deere, 41 Cal.3d 353, 222 Cal.Rptr. 13, 710 P.2d 925, 931 (1985)).3 In this case, however, the evidence put forward by the Public Defender contains at best some mitigation potential balanced by a concomitant and substantial damaging effect. We must ask then, “whether defense counsel’s failure to obtain [this] evidence constituted ineffective assistance of counsel or whether the omission of [this] evidence constituted a manifest injustice and a violation of defendant’s constitutional rights, entitling defendant to post-conviction relief.” Martini IV, supra, 148 N.J. at 454, 690 A.2d 603. That the evidence has limited mitigating value coupled with a potential to harm, and that Martini has expressed his desire to maintain the confidentiality of the evidence, must factor in our analysis.
1. The StricklandlMarsha.il Test
Under Strickland v. Washington, 466 U.S. 668, 687, 104 S.Ct. 2052, 2064, 80 L.Ed.2d 674, 693 (1984), an ineffective assistance of counsel claim is made out upon proof that the representation is both deficient and prejudicial to the defendant. Counsel’s representation is deficient if it falls “below an objective standard of reasonableness,” id. at 688, 104 S.Ct. at 2065, 80 L.Ed.2d at 693; it is prejudicial if “there is a reasonable probability that, but for counsel’s unprofessional errors, the result of the proceeding would have been different,” id. at 694, 104 S.Ct. at 2068, 80 L.Ed.2d at [265]*265698. The Strickland two-prong standard was adopted by this Court in State v. Fritz, 105 N.J. 42, 58, 519 A.2d 336 (1987), as the appropriate measure of counsel’s performance under Article I, Paragraph 10 of the New Jersey Constitution. Subsequently, in State v. Davis, we determined that the Strickland/Fritz standard would “adequately fulfill the constitutional guarantee” in capital cases. 116 N.J. 341, 357, 561 A.2d 1082 (1989).
In Marshall III, for the first time we had occasion to consider the Strickland/Fritz standard in the context of a penalty-phase proceeding. “Our recognition of the profound distinction between our circumscribed appellate-review function and the capital jury’s significantly less-restricted role in deciding between life and death,” led us to modify the prejudice prong of the Strickland/Fritz standard to reflect this dichotomy. Marshall III, supra, 148 N.J. at 250, 690 A.2d 1. Under the reformulation, prejudice is established if “there is a reasonable probability that, but for counsel’s unprofessional errors, the jury’s penalty-phase deliberations would have been affected substantially.” Ibid. As we noted in Marshall III, supra, that modification was “a necessary adaption of the literal Strickland standard to the realistic limitations on appellate review of jury penalty-phase deliberations.” Ibid. We acknowledged that the reformulated standard essentially “equates with” the Strickland Court’s understanding of “reasonable probability ... [as] ‘a probability sufficient to undermine confidence in the outcome,’ ” ibid, (quoting Strickland, supra, 466 U.S. at 694, 104 S.Ct. at 2068, 80 L.Ed.2d at 698), and that it captures the “core meaning” of Strickland, id. at 251, 690 A.2d 1.
2. Deficiency Prong
The Public Defender argues that Martini’s representation was rendered ineffective by trial counsel’s failure to conduct a timely and effective investigation that would have uncovered the omitted evidence, and, then, to use it at Martini’s penalty-phase trial. We reject both claims.
[266]*266“[ C]ounsel has a duty to make reasonable investigations or to make a reasonable decision that makes particular investigations unnecessary.” Strickland, supra, 466 U.S. at 691, 104 S.Ct. at 2066, 80 L.Ed.2d at 695. Whether this duty has been satisfied is measured by “reasonableness in all the circumstances, applying a heavy measure of deference to counsel’s judgments.” Ibid. Put differently, when counsel’s decision to limit an investigation is supported by “reasonable professional judgments,” we will not find deficient performance. Burger v. Kemp, 483 U.S. 776, 794, 107 S.Ct. 3114, 3125, 97 L.Ed.2d 638, 657; accord State v. Savage, 120 N.J. 594, 624, 577 A.2d 455 (1990).
In some cases, whether counsel’s conduct is reasonable “may be determined or substantially influenced by the defendant’s own statements or actions.” Strickland, supra, 466 U.S. at 691, 104 S.Ct. at 2061, 80 L. Ed.2d at 695. Thus, when the “defendant has given counsel reason to believe that pursuing certain investigations would be fruitless or even harmful, counsel’s failure to pursue those investigations may not later be challenged as unreasonable.” Ibid., 466 U.S. at 691, 104 S.Ct. at 2061, 80 L.Ed.2d at 696; see also Dooley v. Petsock, 816 F.2d 885, 890-91 (3d Cir.), cert. denied, 484 U.S. 863, 108 S.Ct. 182, 98 L.Ed.2d 135 (1987) (“A trial counsel cannot be ineffective for failing to raise claims as to which his client has neglected to supply the essential underlying facts when those facts are within the client’s possession____”).
Here, counsel’s failure to discover the omitted evidence was significantly affected by Martini’s conduct. Martini purposely hid information from his attorney and deflected questions put to him because he considered the information to be confidential. Martini’s trial counsel testified at the PCR hearing that he had asked defendant about the possibility that additional evidence existed and that defendant had responded: “it had no bearing on the ease.” When the information was discovered later Martini expressed his desire to keep it from being used in either the PCR hearing or in a new penalty-phase trial. Martini III, supra, 144 N.J. at 619-20, 677 A.2d 1106 (Coleman, J., dissenting). That he [267]*267did not want his attorneys to know about or use the information at his first penalty-phase trial is clear. In these circumstances, it was reasonable for his attorneys to conclude that further investigation would not yield anything useful.
To the extent that Martini’s lawyers had some idea that there was additional evidence, it also was reasonable for them to believe its discovery would result in more harm than good. On being informed about the nature of the evidence, trial counsel testified that, had he discovered it, he would “most likely” have kept it out because of its potentially damaging effect. Even Martini’s original attorney, who had some limited knowledge of the evidence at the time, understood that it was both “possibly good” and “not so hot.” Because the evidence, “although possibly beneficial to the defendant, posed the clear risk of an adverse jury reaction,” Marshall III, supra, 148 N.J. at 256, 690 A.2d 1, the decision to forego further investigation is supported by reasonable professional judgment and does not constitute deficient performance. See Boyd v. Johnson, 167 F.3d 907, 911 (5th Cir.1999) (declaring capital defendant’s attorney “did not perform deficiently in failing to investigate the issue further” because the evidence “may have influenced the jury negatively”), petition for cert. filed, 68 U.S.L.W. 3136, 1999 WL 412897 (June 11, 1999) (No. 98-9745).
3. Prejudice Prong
We begin our analysis of the prejudice prong with the Marshall III reformulation. The Public Defender claims that there is a reasonable probability that the jury’s deliberations would have been affected substantially if the omitted evidence had been presented during Martini’s penalty-phase trial. In Marshall III, we reviewed a similar claim in connection with certain mitigating evidence not adduced at Marshall’s penalty-phase trial, and concluded that the evidence was either flawed or not likely to have affected the jury. Marshall III, supra, 148 N.J. at 252, 690 A.2d 1. Marshall complained that his sister and son would have testified “that his family loved him, and that his execution would [268]*268harm the family.” Ibid. Recognizing that Marshall had “already inflicted grievous harm on [his] family by” contracting for his wife’s murder, and that the jurors would likely “have been offended” by such testimony, we rejected Marshall’s claim. Ibid. Although State v. Morton, 155 N.J. 383, 715 A.2d 228 (1998), was a direct appeal, it also is instructive. In Morton, we rejected another ineffective assistance claim based on trial counsel’s failure to call defendant’s mother and daughter or to bring in a social worker to present a social history of defendant. Id. at 432, 715 A.2d 228. There, we reasoned that the testimony could have portrayed defendant in a negative light or undermined counsel’s attempts to portray defendant’s mother as an inadequate parent. Id. at 431-32, 715 A.2d 228.
The evidence on which the Public Defender has based her ineffective assistance claim in this case is no different. Here, although there is some marginal mitigation value to the omitted material, its potentially harmful nature and the damaging rebuttal opportunity it provides, weigh heavily against presenting it to a jury. We hold that the absence of the evidence at Martini’s penalty-phase trial was not prejudicial.
C. Brady Claim
In Brady v. Maryland, the United States Supreme Court held that “the suppression by the prosecution of evidence favorable to an accused upon request violates due process where the evidence is material either to guilt or to punishment, irrespective of the good faith or bad faith of the prosecution.” 373 U.S. 83, 87, 83 S.Ct. 1194, 1196-97, 10 L.Ed.2d 215, 218 (1963). The Brady rule was later held to apply even where, as here, the defendant makes no formal request for Brady material. United States v. Agurs, 427 U.S. 97, 107, 96 S.Ct. 2392, 2399, 49 L.Ed.2d 342, 351-52 (1976); State v. Knight, 145 N.J. 233, 245, 678 A.2d 642 (1996). In order to establish a Brady violation, the defendant must show that: (1) the prosecution suppressed evidence; (2) the evidence is favorable to the defense; and (3) the evidence is material. Moore [269]*269v. Illinois, 408 U.S. 786, 794-95, 92 S.Ct. 2562, 2568, 33 L.Ed.2d 706, 713 (1972).
Our discussion of the Strickland/Marshall test is directly pertinent to the question whether the proffered evidence in this case is “material.” In United States v. Bagley, the United States Supreme Court adopted a unitary materiality standard applicable in all Brady violation cases. 473 U.S. 667, 682, 105 S.Ct. 3375, 3383, 87 L.Ed.2d 481, 494 (1985); see also Kyles v. Whitley, 514 U.S. 419, 433, 115 S.Ct. 1555, 1565, 131 L.Ed.2d 490, 505 (1995). Under the unitary standard, as adopted by this Court in State v. Knight,4 supra, evidence is “material” if there is a “reasonable probability that, had the evidence been disclosed to the defense, the result of the proceeding would have been different.” Bagley, supra, 473 U.S. at 682, 105 S.Ct. at 3383, 87 L.Ed.2d at 494; accord Kyles, supra, 514 U.S. at 433, 115 S.Ct. at 1565, 131 L.Ed.2d at 505; Knight, supra, 145 N.J. at 246, 678 A.2d 642. A “reasonable probability” is one that is “sufficient to undermine confidence in the outcome.” Bagley, supra, 473 U.S. at 682, 105 S.Ct. at 3383, 87 L. Ed.2d at 494.
As we discussed supra at 261-63, 734 A.2d at 264-66, we cannot say that it is reasonably probable that disclosure of the omitted evidence would have resulted in a different outcome because, although the evidence has some mitigating value, it poses a “clear risk of an adverse jury reaction.” Marshall III, supra, 148 N.J. at 258, 690 A.2d 1. We reach this conclusion for the reasons previously expressed. First, the evidence itself has the potential to negatively influence the jury. See supra at 261-62, 734 A.2d at 265. Second, presentation of the evidence would afford the State the opportunity to present damaging rebuttal evidence, albeit subject to a limiting instruction. Bey III, supra, 129 N.J. at 610, 610 A.2d 814; McDougald, supra, 120 N.J. at 574, [270]*270577 A.2d 419; Rose, supra, 112 N.J. at 503-08, 548 A.2d 1058. We conclude that it is not reasonably probable the result would have been different such that our confidence in the outcome is undermined.5
D. Manifest Injustice
Although the ineffective assistance of counsel and Brady claims fail, we consider whether the omission of the evidence at the penalty-trial phase constituted a manifest injustice. See Koedatich II, supra, 112 N.J. at 330, 548 A.2d 939 (“recognizing there is institutional ‘interest in a reliable penalty determination’”) (quoting Deere, supra, 222 Cal.Rptr. 13, 710 P.2d at 931). Our ultimate goal in reviewing any death sentence is always to ensure that it is reliable, accurate, and nonarbitrary. State v. Biegenwald, 126 N.J. 1, 46-47, 594 A.2d 172 (1991); see also Martini III, supra, 144 N.J. at 614, 677 A.2d 1106 (“The Court is ... required to ensure the integrity of death sentences in New Jersey”). For the reasons expressed in our review of the Public Defender’s Strickland and Brady claims, we are confident that Martini’s death sentence is fair and reliable.
[271]*271In reaching this conclusion, we have weighed both the character of the evidence and Martini’s interest in maintaining its confidentiality. We need not decide whether defendant’s confidentiality interest alone is sufficient to exclude the evidence at a new penalty-phase trial. See Koedatich II, supra, 112 N.J. at 336, 548 A.2d 939. When his interest is set off against the marginal mitigation value of the evidence and its potential to bring about an adverse jury reaction, we have no doubt but that the balance tips against disclosure. See Martini III, supra, 144 N.J. at 611, 677 A.2d 1106.
Another factor must be considered. Since Martini’s conviction and sentence of death, certain events have occurred that would negatively affect a new penalty-phase trial. Martini has twice been convicted of murder in Pennsylvania and Arizona. These convictions would be brought to the attention of the new penalty-phase jury as an aggravating factor. State v. Biegenwald, 110 N.J. 521, 540, 542 A.2d 442 (1988). Also, to prevent the Public Defender from filing a PCR petition, Martini submitted an affidavit acknowledging that he was “not adversely effected [sic] by drugs or alcohol at the time” of the Flax murder and that he committed the murder with “a clear mind.” By his own words, Martini has irreparably subverted his original mitigation case wherein he claimed the c(5)(a) mitigating factor, that he was under the influence of extreme mental or emotional disturbance, because at the time of the murder he used cocaine.6
E. Trial Counsel’s Failure to Discover and Presentthe Burned Screens at the Penalty-Phase
The Public Defender argues that Martini’s trial attorneys rendered ineffective assistance of counsel by failing to find and use [272]*272at both the guilt and penalty-phase trials five burned cocaine screens that were found in Martini’s and Afdahl’s shared apartment and then placed in the State’s physical evidence file. Although Martini’s trial attorneys presented other drug paraphernalia at trial, they missed the five screens among the various items in the State’s file. The Public Defender claims the screens would have provided additional critical support for the defense theory that Martini’s drug addition had diminished his capacity and, more specifically, that he had used cocaine around the time of the murder.
Trial counsel’s failure to find the burned cocaine screens was inadvertent. Presumably, Martini knew the screens existed although he never mentioned them. The question remains, however, “whether the production of additional mitigating evidence would have been likely to have a substantial effect on the jury’s deliberations.” Marshall III, supra, 148 N.J. at 250-51, 690 A.2d 1; see also Morton, supra, 155 N.J. at 431, 715 A.2d 228. Given counsel’s presentation of other drug paraphernalia, including a glass cocaine pipe and a glass vial, and a certified laboratory report indicating that both the pipe and the vial contained trace elements of cocaine, the burned screens would have added only cumulative weight to the argument that Martini had used cocaine around the time of the murder.
We do not believe that this additional evidence would have substantially affected the jury’s deliberations and, therefore, also reject the Public Defender’s claim of ineffective assistance of counsel on this issue.
F. Trial Court’s Failure to Inform the Jury that the Alternative to a Death Sentence Might Include a Period of Parole Ineligibility Beyond Thirty Years
The Public Defender contends that the failure of the trial court to inform the jury about Martini’s aggregate parole ineligibility, which could exceed thirty years, denied Martini his right to due process of law and subjected him to cruel and unusual punishment. [273]*273On direct appeal, we rejected this argument. Martini I, supra, 131 N.J. at 308, 619 A.2d 1208. Because defense counsel had not asked the trial court to so inform the jurors, and because the jury knew “of the practical consequences of defendant’s life sentence,” we held that the trial court’s failure to instruct the jury concerning the aggregate period of parole ineligibility was not error. Id. at 313, 619 A.2d 1208. After our decision, the United States Supreme Court decided Simmons v. South Carolina, 512 U.S. 154, 114 S.Ct. 2187, 129 L. Ed.2d 133 (1994). The Public Defender now argues that under Simmons, the Court must reverse on the lack of an instruction concerning sentencing alternatives. We disagree.
In Simmons, the State presented “future dangerousness [as] a factor for the jury to consider when fixing the appropriate punishment.” Id. at 157, 114 S.Ct. at 2190, 129 L.Ed.2d at 139. In response, the defendant sought an instruction that would explain to the jury “that ‘life imprisonment’ did not carry with it the possibility of parole in [defendant’s] case.” Id. at 158, 114 S.Ct. at 2191, 129 L.Ed.2d at 139. The trial court refused; moreover, when the jury asked about the possibility of parole, the court instructed the jurors “ ‘not to consider parole or parole eligibility in reaching [a] verdict.’” Id. at 160, 114 S.Ct. at 2192, 129 L.Ed.2d at 140.
The Supreme Court vacated Simmons’s death sentence. The Court explained:
[ I]f the State rests its ease for imposing the death penalty at least in part on the premise that the defendant will be dangerous in the future, the fact that the alternative sentence to death is life without parole will necessarily undercut the State’s argument regarding the threat the defendant poses to society. Because truthful information of parole ineligibility allows the defendant to “deny or explain” the showing of future dangerousness, due process plainly requires that he be allowed to bring it to the jury’s attention by way of argument by defense counsel or an instruction from the court.
[Id. at 168-69, 114 S.Ct. at 2196, 129 L.Ed.2d at 145-46.]
First, in the instant case the State has not offered “defendant’s ‘future dangerousness’ as an aggravating factor,” nor could it do so. State v. Loftin, 146 N.J. 295, 371, 680 A.2d 677 [274]*274(1996) (Loftin I). As we pointed out in Loftin I, “[f]uture dangerousness is not an aggravating factor in New Jersey, and our statute limits prosecutors to the enumerated aggravating factors.”7 Ibid. Although we determined in Loftin I that “the holding of Simmons [was] therefore inapplicable ....,” ibid., we required that
in future cases, if the court, based on the evidence presented believes that there is a realistic likelihood that it will impose a sentence to be served consecutively to any of defendant’s prior sentences, in the event the jury does not return a death sentence, the jury should be so informed.
[Id. at 372, 680 A.2d 677.]
Second, Martini’s attorney “effectively made the argument that defendant was not likely to live long enough to be released after a thirty-year period of parole ineligibility.” Martini I, supra, 131 N.J. at 312-13, 619 A.2d 1208. Most important, the jury knew that Martini, already sixty-years old at the time of trial, would be approaching ninety before he could be released and would, in all likelihood, die in prison. This is not a case in which “[t]he jury was left to speculate about [the defendant’s] ... future dangerousness.” Simmons, supra, 512 U.S. at 165-66, 114 S.Ct. at 2195, 129 L.Ed.2d at 144. Martini was not, in these circumstances, denied due process of law.
G. International Law
In State v. Nelson, we rejected the Public Defender’s argument that New Jersey’s death penalty violates international customary law, concluding that “[t]he United States of America has not subscribed to any international human rights accord that has invalidated the death penalty.” 155 N.J. 487, 512, 715 A.2d 281 (1998), cert. denied, — U.S. —, 119 S.Ct. 890, 142 L.Ed.2d 788 (1999) (citations omitted). We reject the Public Defender’s claim once again in this case.
[275]*275H. Systemic Racial Discrimination
In State v. Loftin, we reaffirmed our commitment to “ ‘the prevention of any impermissible discrimination in imposing the death penalty.’ ” 157 N.J. 253, 298, 724 A.2d 129 (1999) (Loftin II) (quoting State v. Marshall, 130 N.J. 109, 135, 613 A.2d 1059 (1992) ). We found, however, that the results of the statistical models developed as part of the Court’s frequency review have not “‘relentlessly documented the risk’ of racial disparity in the imposition of the death penalty.” Id. at 315, 724 A.2d 129; see also State v. Chew, 159 N.J. 183, 223, 731 A.2d 1070 (1999); State v. Cooper, 159 N.J. 55, 115-16, 731 A.2d 1000 (1999); State v. Harvey, 159 N.J. 277, 319-20, 731 A.2d 1121 (1999). We therefore also reject the Public Defender’s claim of systemic racial discrimination for the reasons stated in Loftin II.
I. Cumulative Effect of the Errors
The Public Defender’s final claim is that the cumulative effect of the errors in this case warrants reversal of Martini’s death sentence. The errors complained of are not independent of the claims we have already addressed. We conclude that the errors in the aggregate were not clearly capable of affecting the jury’s determination that death is the appropriate sentence. State v. Marshall, 123 N.J. 1, 170, 586 A.2d 85 (1991).
Ill
CONCLUSION
We affirm the denial of defendant’s petition for post-conviction relief.