(This syllabus is not part of the opinion of the Court. It has been prepared by the Office of the Clerk for the convenience of the reader. It has been neither reviewed nor approved by the Supreme Court. Please note that, in the interests of brevity, portions of any opinion may not have been summarized).

PORITZ, C.J., writing for a majority of the Court.

    The Supreme Court previously affirmed Loftin's conviction and death sentence for the murder of Gary Marsh. In this appeal, the Court considers Loftin's request for proportionality review of his death sentence. This appeal also requires the Court to consider the constitutionality of an amendment to N.J.S.A. 2C:11-3e that limits proportionality review to those cases in which a jury has sentenced a defendant to death.

HELD: The Supreme Court will not apply the 1992 statutory amendment limiting proportionality review to cases in which the defendant has been sentenced to death until reviewing the findings and recommendations of a newly-appointed Special Master. Loftin has not met his burden of proving that his death sentence is disproportionate or that race has operated as an impermissible factor in the imposition of the death penalty.

1. Proportionality review is intended to ensure that the death penalty is being administered in a rational, non-arbitrary and evenhanded manner. It also provides a mechanism by which death sentences may be monitored to prevent impermissible discrimination in imposing the death penalty. In performing proportionality review, the Court conducts a frequency analysis using statistical methods, and a precedent-seeking review consisting of a traditional, case-by-case analysis. These methods compare the case to others that have been found to have either similar fact patterns or similar levels of culpability, and are used to determine whether the sentence imposed on the defendant is disproportionate to the sentences imposed in those other cases. From the beginning, there has been extensive critical commentary on the frequency analysis methodologies accepted by the Court. The Court has chosen in each case to discuss the results of the frequency analysis tests despite their acknowledged deficiencies, as an adjunct to its precedent-seeking review. (pp. 5-22)

2. The Court has held that under the proportionality review provision prior to the 1992 amendment, the appropriate universe of cases included not only all cases in which the death penalty had been sought, but also death eligible homicides where the prosecutor elected not to seek the death penalty. The Court has deemed the 1992 amendment limiting the universe to death-sentenced cases to be inapplicable to appeals that were pending as of the effective date of the amendment. Loftin was convicted in July 1994, after the amendment's effective date. (pp. 23-25)

3. At issue in this case is the process by which the Court fulfills its substantive constitutional responsibility to review matters on appeal and, specifically, to review capital causes. Appellate review is an exclusive function of the judiciary secured against legislative interference. However, the Court will uphold a legislative enactment absent constitutional repugnance. Experience teaches that proportionality review methodologies are not without substantial shortcomings and, accordingly, warrant careful reconsideration. There are several areas of concern that require reconsideration, including the size of the universe of comparison cases. Because these issues cannot be resolved on the record before the Court, a Special Master is appointed to conduct additional fact-finding and make recommendations to the Court. On receipt of the report, the Court will be in a position to determine whether the statutory limitation on the proportionality review universe prevents meaningful appellate review. Until then the Court will continue to use the full universe of death-eligible cases. (pp. 25-37)

4. The Court's use of all death-eligible homicides in the universe of cases enables it to consider possible discrimination in the prosecutors' charging decisions as well as in the juries' sentencing decisions. Yet, the reliability of the data still concerns the Court. A prosecutor must decide what to do based on a complex of factors -- the decision does not necessarily reflect a determination of deathworthiness. There are also practical difficulties attendant to data collection and analysis of noncapital cases, involving subjective determinations by AOC staff. Where a defendant pled guilty, these determinations must be made without the benefit of a trial. The relatively small size of the proportionality review database suggests that the cumulative effect of individual case errors could undermine the reliability of the statistical models. For this reason, there should be additional fact-finding concerning the proper scope of the proportionality review universe by the Special Master. (pp. 38-44)

5. The Court has acknowledged that frequency analysis has so far fallen short of its potential. Much of the difficulty has arisen because of the small size of the pool of cases for comparison purposes, and the database is not growing at the rate that had been expected. The Special Master is directed to consider particular problems with the statistical methods used, with a view toward making frequency analysis more useful for the Court. However, the numerical-preponderance-of-aggravating-and-mitigating-factors test, which compares a case to other cases having the same number of aggravating and mitigating factors, has not contributed to the Court's proportionality review and is abandoned by the Court. (pp. 44-52)

6. The Court's concerns with respect to precedent-seeking review also arise from questions about the reliability of the data. Precedent-seeking relies on the same case-classification scheme employed in the salient-factors test, which is part of the frequency analysis. The Special Master will consider whether some reduction in the number of case classifications is possible without compromising the principle that only similar cases are to be compared. (pp. 52-54)

7. The Court has rejected prior claims of racial disparities in sentencing that were based on the statistical models, given the insufficient number of cases in the statistical database. There has been an increase in the number of death-sentenced and death-eligible cases since the last appeal, DiFrisco III. Because of the larger database, the AOC used logistic regression procedures in its analyses, and informed the Court that there was a possible race effect in jury decision making. Loftin cites to these analyses in support of his claim of racial disparity, while the State vigorously disputes the accuracy and reliability of the models. The Court appointed a Special Master to make findings and recommendations relating to Loftin's race as a possible factor in his death penalty. In sum, the Special Master concluded that the Court is no closer than it was in the past to statistical evidence of race effect. The Court's statistical methods were developed for conducting individual proportionality review, not for the purpose of assessing systemic discrimination. In addition, the Special Master found that a race-blind survey of fifty experienced trial judges who ranked penalty-trial defendants by culpability challenged the accuracy and reliability of the statistical models indicating a race effect. The newly-appointed Special Master is asked to develop statistical models for more reliable regression studies of race effect. The Master should also consider the appointment of a panel of judges to perform independent verification of the culpability ratings derived from the statistical models. (pp. 55-84)

8. Proportionality review has been conducted as a separate proceeding following a defendant's unsuccessful direct appeal. This was intended to conserve resources, because such a review is not necessary if the direct appeal is successful. The Court recognizes, however, that this practice also draws out the process when a death sentence is affirmed. The Special Master is requested to develop a factual record and issue findings concerning the desirability of maintaining proportionality review as a separate proceeding or, alternately, conducting such review in connection with a defendant's direct appeal. (pp. 84-85)

9. Applying the frequency analysis to Loftin, the Court finds that he has not offered evidence that his sentence is disproportionate. (pp. 85-113)

10. Under the precedent-seeking review, which involves traditional, case-by-case review of similar death-eligible cases, the Court does not find that Loftin's death sentence should be reversed. (pp. 113-130)

    Loftin's sentence of death is AFFIRMED.

     JUSTICE HANDLER, dissenting, is of the view that Loftin relentlessly documents a risk that the death penalty is imposed in a racially discriminatory manner, rendering the administration of capital punishment in New Jersey unconstitutional. He also opposes the application of proportionality review to Loftin's case in light of the Court's acknowledgment of flaws in the current methodology and the need for revisions. Finally, he finds the 1992 statutory amendment limiting the universe of cases to those in which a death sentence was imposed facially unconstitutional.

     JUSTICES POLLOCK, O'HERN, GARIBALDI, STEIN, and COLEMAN join in CHIEF JUSTICE PORITZ's opinion. JUSTICE HANDLER has filed a separate dissenting opinion.
                                SUPREME COURT OF NEW JERSEY
A- 86 September Term 1996

STATE OF NEW JERSEY,

    Plaintiff-Respondent,

        v.

DONALD LOFTIN,

    Defendant-Appellant.

        Argued March 18, 1997 -- Decided February 1, 1999

On Proportionality Review of a Death Sentence imposed in the Superior Court, Law Division, Mercer County.

Mordecai D. Garelick and Daniel V. Gautieri, Assistant Deputy Public Defenders, argued the cause for appellant (Ivelisse Torres, Public Defender, attorney; Mr. Garelick, Mr. Gautieri and Claudia Van Wyk, Deputy Public Defender II, on the briefs).

Paul H. Heinzel, Deputy Attorney General, argued the cause for respondent (Peter Verniero, Attorney General of New Jersey, attorney).

Lawrence S. Lustberg argued the cause for amici curiae Association of Criminal Defense Lawyers of New Jersey and New Jersey State Conference of NAACP Branches (Gibbons, Del Deo, Dolan, Griffinger & Vecchione, attorneys; Mr. Lustberg, James E. Ryan and Laura K. Abel, on the briefs).

I.    The Origin and History of Proportionality Review . . . . .     5

    A.     From Furman to Pulley . . . . . . . . . . . . . . . .     5

    B.     Proportionality Review in Other States. . . . . . . . 7

    C.     Proportionality Review in New Jersey. . . . . . . . . 17

II.    The Constitutionality of N.J.S.A. 2C:11-3e as Amended. . . 23

    A.     Pending Appeals . . . . . . . . . . . . . . . . . . . 23

    B.     The Supreme Court's Appellate Review Function . . . . 25

    C.     Application of Proportionality Review . . . . . . . . 35

         1.     The Scope of the Statistical Universe
            of Comparison Cases. . . . . . . . . . . . . . . 38

        2.    Individual Proportionality Review. . . . . . . . 44

            a.    Frequency Analysis. . . . . . . . . . . . . 44

                 i.    Salient-Factors Test . . . . . . . . . 46

                 ii.    Numerical-Preponderance-of-
                    Aggravating-and-Mitigating-
                    Factors Test . . . . . . . . . . . . . 49

                iii.    Index-of-Outcomes Test . . . . . . . . 51
            
            b.    Precedent-Seeking Review. . . . . . . . . . 52

        3.    Systemic Proportionality Review and Possible
             Racial Disparity in the Imposition of the
            Death Penalty. . . . . . . . . . . . . . . . . . 55

            a. Race as a Predictor of Outcome . . . . . . . 58

            b. Review of the Statistical Models . . . . . . 62

        4.    Proportionality Review and Its Status as a
            Separate Proceeding in Death Penalty Appeals . . 84

III.    Application of the Methods of Individual Proportionality
    Review to Loftin . . . . . . . . . . . . . . . . . . . . . 85

    A.    Facts . . . . . . . . . . . . . . . . . . . . . . . . 86

    B.    Focus of Review . . . . . . . . . . . . . . . . . . . 92

        1.    The Universe of Cases. . . . . . . . . . . . . . 95

        2.    Method of Classifying Cases . . . . . . . . . . 95

    C.    Comparison of Cases . . . . . . . . . . . . . . . . . 97

        1.    Comparison Group . . . . . . . . . . . . . . . . 98

        2.    Frequency Analysis . . . . . . . . . . . . . . .101

            a.    Salient-Factors Test. . . . . . . . . . . .102

            b.    Index-of-Outcomes Test. . . . . . . . . . .105

            c.    Frequency-Analysis Conclusion. . . . . . . 112

        3.    Precedent-Seeking Review. . . . . . . . . . . . 113

            a.    Assessment of Defendant's Culpability. . . 114

                i.    Moral Blameworthiness . . . . . . . . 115

                ii.    Degree of Victimization . . . . . . . 117

                iii.    Character of Defendant. . . . . . . . 118

            b.    Comparison of Defendant's Case to the
                B Cases. . . . . . . . . . . . . . . . . . 119

    D.    Other Arguments. . . . . . . . . . . . . . . . . . . 129

IV.    Conclusion. . . . . . . . . . . . . . . . . . . . . . . . 129

    Appendix A. . . . . . . . . . . . . . . . . . . . . . . . 1-a

Appendix B. . . . . . . . . . . . . . . . . . . . . . . . 1-a    

    Appendix C. . . . . . . . . . . . . . . . . . . . . . . . 1-a

                Comparison Case Summaries. . . . . . . . . 1-a

                I.    Prior Murderers with Two Additional
                    Aggravating Factors or Particular
                    Violence/Terror: B(1) . . . . . . . . 1-a

                    A)    George Booker (1 and 2). . . . . 1-a

                    B)    John Fauntenberry. . . . . . . . 3-a

                    C)    Richard Feaster (2). . . . . . . 5-a

                    D)    James Koedatich (1A) . . . . . . 8-a

                    E)    James Koedatich (1B) . . . . . . 9-a

                II.    Prior Murderers with One Additional                              Aggravating Factor or Particular                                  Violence/Terror: B(2) . . . . . . . .10-a

                    A)    Marko Bey (2B) . . . . . . . . .10-a

                    B)    Richard Biegenwald (1A). . . . .13-a

                    C)    Richard Biegenwald (1B). . . . .15-a

                    D)    Richard Biegenwald (1C). . . . .15-a

                    E)    Bryan Coyle (1A) . . . . . . . .15-a

                    F)    Bryan Coyle (1B) . . . . . . . .17-a

                    G)    Samuel Erazo (1A). . . . . . . .17-a

                    H)    Samuel Erazo (1B). . . . . . . .19-a

                    I)    William Godette . . . . . . . .20-a

                    J)    Frank Pennington . . . . . . . .22-a

                    K)    Frank Pennington (1B). . . . . .24-a

                    L)    Braynard Purnell (1A). . . . . .24-a

                    M)    Braynard Purnell (1B). . . . . .26-a

                    N)    Thomas Ramseur. . . . . . . . . 26-a

                    O)    Carlos Vasquez. . . . . . . . . .28-a

                III.    Prior Murderers with No Other
                    Aggravating Circumstances or
                    Particular Violence/Terror: B(3) . . .29-a

                    A)    Richard Biegenwald (2). . . . . .29-a

                    B)    Jihad Muhammed. . . . . . . . . .31-a

                    C)    Alberto Nieves. . . . . . . . . .32-a

                    D)    Thomas Williams . . . . . . . . .34-a     The opinion of the Court was delivered by
PORITZ, C.J.

    In State v. Loftin, 146 N.J. 295 (1996) (Loftin I), we affirmed defendant Donald Loftin's conviction and sentence of death for the murder of Gary Marsh. We also acknowledged defendant's request for proportionality review of his death sentence pursuant to N.J.S.A. 2C:11-3e. Id. at 397. This appeal requires us first to consider the constitutionality of an amendment to N.J.S.A. 2C:11-3e that limits proportionality review to a specific group of similar cases in which a jury has sentenced the defendant to death and, then, to conduct defendant's review.
    Proportionality review, although statutory in origin, is carried out by this Court in the exercise of its general authority as an appellate tribunal, N.J. Const. art. VI, § 2,
¶ 2, and its specific exclusive jurisdiction over capital causes, id. at § 5, ¶ 1(c). This authority is central to our primary function as the Court of last resort in the state judicial system and carries with it the power to determine the scope and content of appellate review. The integrity of appellate review by the Court is critical to the judiciary as an independent and coequal branch of government, and to the separation of powers among the executive, legislative and judicial branches. In exercising its authority in this case, the Court must ultimately decide whether the limitation on the proportionality review universe imposed by the Legislature precludes meaningful appellate review.
    Prior to this case, we established the size of the proportionality review universe to include both death-eligible defendants and defendants who proceed to a penalty trial. State v. Marshall, 130 N.J. 109, 134, 137 (1992) (Marshall II), cert. denied, 507 U.S. 929, 113 S. Ct. 1306, 122 L. Ed.2d 694 (1993). We anticipated that such broad categories would provide the most useful information about how decisions are made in the capital sentencing system by prosecutors and by juries. Id. at 132-37. We also decided to conduct our review in two parts: a statistical comparison we call "frequency review," and a descriptive analytic comparison of like cases described as "precedent-seeking review." Id. at 152-59. Always, we have sought a principled, careful approach "to ensure that the death penalty is being administered in a rational, non-arbitrary, and evenhanded manner, fairly and with reasonable consistency." Id. at 131.
    Despite these efforts, many questions have been raised by our early cases, the parties, the Special Master appointed to consider Loftin's allegations of racial disparity, and the Administrative Office of the Courts (AOC) about our present system of proportionality review. These questions cover a broad range of factual issues that must be resolved before we can rule on whether the statutory limitation unduly restricts appellate review by this Court. To this end, we are remanding these issues to a Special Master, appointed to hear and take testimony and to report to the Court. His general charge is to examine the proportionality review methodology used by the Court since Marshall II was decided over six years ago, and to test the assumptions on which the current system is based. Through a remand, a record can be developed that will enable us to consider the effect of the statute on our review function, including our ability to address any future claims that New Jersey's system of capital punishment operates in an invidiously discriminatory manner.
    We are cognizant of the Legislature's clearly expressed intent to limit the boundaries of proportionality review and would not lightly reject its views. Our consideration of those boundaries must, however, await the findings and recommendations of the Special Master. Until we have had the benefit of his report, due pursuant to our Order on May 14, 1999, we will continue, with one exception described below, see infra at ___ (slip op. at 49-51), to carry out proportionality review as before. Based on our proportionality review herein, we hold that defendant has not shown his death sentence to be disproportionate to the penalty imposed in similar cases.

The Origin and History of Proportionality Review

    In Marshall II, we observed that "[t]he best way to understand the concept of proportionality review is to understand its origin." 130 N.J. at 124. That observation remains true today. It is helpful, also, to consider the history of proportionality review both in this state and in our sister states to gain perspective on the role of this form of review in New Jersey's death penalty scheme.

    A.    From Furman to Pulley

    Proportionality review arose in response to the United States Supreme Court's decision in Furman v. Georgia, 408 U.S. 238, 92 S. Ct. 2726, 33 L. Ed.2d 346 (1972), wherein the Court held that a Georgia statute permitting defendants to be sentenced to death at the unfettered discretion of the judge or jury violated the Eighth Amendment prohibition on cruel and unusual punishment. Id. at 239-40, 92 S. Ct. at 2727, 33 L. Ed. 2d at 350; see also U.S. Const. amend. VIII ("Excessive bail shall not be required, nor excessive fines imposed, nor cruel and unusual punishments inflicted"). Justice Stewart, in his concurring opinion, described "legal systems that permit . . . [the death] penalty to be so wantonly and so freakishly imposed" as "cruel and unusual in the same way that being struck by lightening is cruel and unusual." Furman, supra, 408 U.S. at 309-10, 92 S. Ct. at 2762-63, 33 L. Ed. 2d at 390 (Stewart, J., concurring).
    Four years later, the United States Supreme Court upheld statutes passed in response to Furman by Georgia, Texas and Florida, finding that the procedural safeguards provided by those statutes would prevent the death penalty from being imposed "capriciously or in a freakish manner." Gregg v. Georgia, 428 U.S. 153, 195, 96 S. Ct. 2909, 2935, 49 L. Ed.2d 859, 886-87 (1976); see also Jurek v. Texas, 428 U.S. 262, 96 S. Ct. 2950, 49 L. Ed.2d 929 (1976); Proffitt v. Florida, 428 U.S. 242, 96 S. Ct. 2960, 49 L. Ed.2d 913 (1976).
    The Georgia statute sustained by the Court in Gregg bifurcated capital proceedings into separate guilt-phase and penalty-phase trials, and provided that during the penalty phase the judge or jury would hear evidence of mitigating and aggravating factors. 428 U.S. at 163-64, 96 S. Ct. at 2920-21, 49 L. Ed. 2d at 869-70. The defendant could be sentenced to death only if the judge or jury found that at least one of the statutory aggravating factors was present and outweighed the mitigating factors. Id. at 165-66, 96 S. Ct. at 2921-22, 49 L. Ed. 2d at 870. The Georgia statute also provided for direct appeal to the state supreme court which, among other things, was to conduct a proportionality review to determine "'[w]hether the sentence of death is excessive or disproportionate to the penalty imposed in similar cases, considering both the crime and the defendant'." Id. at 166-67, 96 S. Ct. at 2922, 49 L. Ed. 2d at 871 (quoting Ga. Code Ann. § 27-2537 (Supp. 1975)).
    States seeking to enact constitutional death penalty statutes followed the statute upheld in Gregg like a recipe, careful to include provisions for appellate proportionality review. See infra at ___ (slip op. at 8-9). Six years later, however, in Pulley v. Harris, 465 U.S. 37, 104 S. Ct. 871, 79 L. Ed.2d 29 (1984), the United States Supreme Court held that proportionality review was not "indispensable" to a constitutionally acceptable capital punishment statute. Id. at 45, 104 S. Ct. at 876, 79 L. Ed. 2d at 37.

    B.    Proportionality Review in Other States
    Gregg did "not intend to suggest that only . . . procedures [similar to the Georgia procedures] would be permissible under Furman or that any sentencing system constructed along . . . [such] general lines would inevitably satisfy the concerns of Furman." 428 U.S. at 195, 96 S. Ct. at 2935, 49 L. Ed. 2d at 887. Nonetheless, in the 1970s and early 1980s, twenty-five states enacted capital punishment statutes that required appellate proportionality review in all capital cases. See Ala. Code § 13A-5-53(b)(3) (enacted 1981); Conn. Gen. Stat. § 53a-46b (enacted 1980); Del. Code Ann. tit. 11 § 4209(g)(2)(a) (enacted 1977); Ga. Code. Ann. § 17-10-35(c)(3) (enacted 1973); Idaho Code § 19-2827(c)(3) (enacted 1977); Ky. Rev. Stat. Ann. § 532.075(3)(c) (enacted 1976); La. Code Crim. Proc. Ann. art. 905.9 (enacted 1976); Md. Ann. Code, art. 27, § 414(e)(4) (enacted 1978); Mass. Gen. Laws Ann. ch. 279, § 71 (enacted 1982); Miss. Code Ann. § 99-19-105(3)(c) (enacted 1977); Mo. Ann. Stat. § 565.035 (enacted 1983); Mont. Code. Ann. § 46-18-310(1)(c) (enacted 1977); Neb. Rev. Stat. § 29-2521.03 (enacted 1978); Nev. Rev. Stat. § 177.055(2)(d) (enacted 1977); N.M. Stat. Ann. § 31-20A-4(C)(4) (enacted 1979); N.C. Gen. Stat. § 15A-2000(d)(2) (enacted 1977); Ohio Rev. Code. Ann. § 2929.05(A) (enacted 1981); Okla. Stat. Ann. tit. 21, § 701.13(C)(3) (enacted 1976); 42 Pa. Cons. Stat. Ann. § 9711(h)(3)(iii) (enacted 1974); S.C. Code Ann. § 16-3-25(C)(3) (enacted 1977); S.D. Codified Laws § 23A-27A-12(3) (enacted 1979); Tenn. Code Ann. § 39-13-206(c)(1)(D) (enacted 1977); Va. Code. Ann. § 17-110.1(C)(2) (enacted 1977); Wash. Rev. Code Ann. § 10.95.130(2)(b) (enacted 1981); Wyo. Stat. Ann. § 6-2-103(d)(iii) (enacted 1982). These statutes were passed because of the then widely-held perception that the Supreme Court would not uphold state capital punishment legislation that lacked such provisions. See Leigh B. Bienen, The Proportionality Review of Capital Cases by State High Courts After Gregg: Only "The Appearance of Justice"?, 87 J. Crim. L. & Criminology 130, 140 (1996).
    After Pulley, nine states repealed their proportionality review requirements. See 1995 Conn. Legis. Serv. P.A. 95-16(West); 1994 Idaho Sess. Laws ch. 127; 1992 Md. Laws ch. 331; 1985 Nev. Stat. ch. 527 § 1; 1985 Okla Sess. Laws ch. 265 (West), § 1; 1997 Pa. Legis. Serv. Act 1997-28 (West); 1992 Tenn. Pub. Acts ch. 952; 1998 Va. Acts ch. 872; 1989 Wyo. Sess. Laws ch. 171, § 2. A substantial number of jurisdictions, however, conduct proportionality review today pursuant to express statutory authority. In addition to the twenty-five states that enacted proportionality review provisions in the 1970s and early 1980s, three states passed similar statutes subsequent to Pulley, including Tennessee after having repealed its earlier statute, see N.H. Rev. Stat. Ann. § 630:5(XI) (enacted 1986); N.Y. Crim. Proc. Law § 470.30 (enacted 1995); Tenn. Code Ann. § 39-13-206(c)(1)(D) (enacted 1992). Today, twenty states, including New Jersey, conduct statutory proportionality review. In one state, Florida, the state supreme court has declared the court's intention to conduct comparative review on its own initiative. See Sinclair v. Florida, 657 So.2d 1138, 1142 (Fla. 1995).
    As might be expected, the absence of any uniform requirements enforceable under the federal Constitution has led, over the years, to variation in the conduct of proportionality review. Thus, for example, the scope of the pool or "universe" of comparison cases used for proportionality review varies among the states. New York and Washington have defined broad universes encompassing some homicide cases that were not capitally prosecuted. See N.Y. Jud. Law § 211-a; N.Y. Ct. Rules § 510.18 (authorizing collection of case data for every criminal action in which defendant is indicted for first-degree murder); Wash. Rev. Code Ann. §§ 10.195.120, 10.195.130(2)(b) (authorizing collection of case data for every criminal action in which defendant is convicted of aggravated first-degree murder, regardless of whether defendant is capitally prosecuted).
    Some states have limited the universe of comparison cases to those cases advancing to a penalty-phase trial. See, e.g., South Dakota v. Rhines, 548 N.W.2d 415, 455-56 (S.D.), cert. denied, ___ U.S. ___, 117 S. Ct. 522, 136 L. Ed.2d 410 (1996) (finding that "'[b]ecause the aim of proportionality review is to ascertain what other capital sentencing authorities have done with similar capital murder offenses, the only cases that could be deemed similar . . . are those in which imposition of the death penalty was properly before the sentencing authority for determination'") (quoting Tichnell v. Maryland, 468 A.2d 1, 15-16 (Md. 1983), cert. denied, 466 U.S. 993, 104 S. Ct. 2374, 80 L. Ed.2d 846 (1984), and citing Flamer v. Delaware, 490 A.2d 104, 139 (Del.), cert. denied, 464 U.S. 865, 104 S. Ct. 198, 78 L. Ed.2d 173 (1983), and cert. denied, 474 U.S. 865, 106 S. Ct. 185, 88 L. Ed 2d 154 (1985)); Flamer, supra, 490 A. 2d at 139 (declaring "it inherently fair, logical and necessary to prevent disproportionate sentencing that this Court compare the sentence below to the facts and circumstances of cases in which a capital sentencing proceeding was actually conducted, whether the murderers have been sentenced to life imprisonment or death"); Missouri v. Bolder, 635 S.W.2d 673, 685 (Mo. 1982) (finding court's "inquiry would be unduly slanted were [the court] to compare only those cases in which the death penalty has been imposed" and determining "as similar [t]hose cases in which both death and life imprisonment were submitted to the jury") (internal quotation marks omitted) (alteration in original), cert. denied, 459 U.S. 1137, 103 S. Ct. 770, 74 L. Ed.2d 983 (1983). Other states have defined the universe of comparison cases to include only those cases in which a death sentence was imposed. See, e.g., Sanborn v. Kentucky, 892 S.W.2d 542, 556 (Ky. 1994) (considering all cases in which death penalty was imposed, as required by statute), cert. denied, 516 U.S. 854, 116 S. Ct. 154, 133 L. Ed.2d 98 (1995); Nebraska v. Palmer, 399 N.W.2d 706, 737 (1986) (finding universe of death-sentenced cases to be "a threshold requirement for comparative study"), cert. denied, 484 U.S. 872, 108 S. Ct. 206, 98 L. Ed.2d 157 (1987); South Carolina v. Copeland, 300 S.E.2d 63, 74 (S.C. 1982) (relying only on death-sentenced cases because "[f]act findings of the trial court . . . provide a fundamental line of demarcation" and because larger universe would cause court to "enter a realm of pure conjecture" and to engage in "intolerable speculation"), cert. denied, 460 U.S. 1103, 103 S. Ct. 1802, 76 L. Ed.2d 367 (1983).
    Similarly, there is considerable variation among the states in respect of the methods used both to select cases for comparison purposes and to make factual comparisons among selected cases. By way of illustration, the Tennessee Supreme Court has identified at least seventeen separate factors to be used in selecting and comparing similar cases including, among others, the means of death, the manner of death, the motivation for the killing, the absence or presence of premeditation, the defendant's prior criminal record or prior criminal activity, the defendant's cooperation with authorities, and the defendant's remorse. Tennessee v. Bland, 958 S.W.2d 651, 667 (Tenn. 1997), cert. denied, __ U.S. __, 118 S. Ct. 1536, 140 L. Ed.2d 686 (1998). The Washington Supreme Court considers four factors: "(1) the nature of the crime, (2) the aggravating circumstances, (3) the defendant's criminal history and (4) the defendant's personal history." Washington v. Brown, 940 P.2d 546, 562 (Wash. 1997), cert. denied, ___ U.S. ___, 118 S. Ct. 1192, 140 L. Ed.2d 322 (1998). In contrast, many courts have issued proportionality determinations without a particularized statement describing the comparative process. See, e.g., DeYoung v. Georgia, 493 S.E.2d 157, 168 (Ga. 1997) (referring without discussion to appendix listing similar cases where death penalty upheld), cert. denied, ___ U.S. ___, 118 S. Ct. 1848, 140 L. Ed.2d 1097 (1998); Sanborn, supra, 892 S.W. 2d at 556-57 (incorporating by reference list of cases cited in previous decisions and referring to list of five additional cases); Davis v. Mississippi, 660 So.2d 1228, 1261-62 (Miss. 1995) (referring without discussion to appendix with list of capital cases court previously affirmed), cert. denied, 517 U.S. 1192, 116 S. Ct. 1684, 134 L. Ed.2d 785 (1996); Pennsylvania v. Uderra, 706 A.2d 334, 342 (Pa. 1998) (making passing reference to statistical data without mention of similar cases).
    Although eleven state supreme courts have vacated death sentences as disproportionate, most have done so rarely. See, e.g., Hall v. Georgia, 244 S.E.2d 833, 839 (Ga. 1978) (only one aggravating factor and co-defendant received life sentence); Idaho v. Pratt, 873 P.2d 800, 806 (Idaho 1993) (no prior criminal record); Missouri v. McIlvoy, 629 S.W.2d 333, 341 (Mo. 1982) (minimal juvenile criminal record, limited education, limited intelligence, substantial alcohol problems, weak follower of co-defendant who received life sentence, and promptly turned himself in to police). The Florida Supreme Court, however, has vacated over thirty death sentences based on proportionality review, see, e.g., Williams v. Florida, 707 So.2d 683 (Fla. 1998); Jones v. Florida, 705 So.2d 1364 (Fla. 1998); Voorhees v. Florida, 699 So.2d 602 (Fla. 1997); Curtis v. Florida, 685 So.2d 1234 (Fla. 1996), cert. denied, ___ U.S. ___, 117 S. Ct. 2521, 138 L. Ed.2d 1022 (1997); Sinclair, supra, and the North Carolina Supreme Court has vacated at least seven death sentences on proportionality grounds, see, e.g., North Carolina v. Benson, 372 S.E.2d 517 (N.C. 1988); North Carolina v. Stokes, 352 S.E.2d 653 (N.C. 1987); North Carolina v. Rogers, 341 S.E.2d 713 (N.C. 1986). It is perhaps significant that Florida and North Carolina have relatively large death-row populations compared to other states, see Bienen, supra, 87 J. Crim. L. & Criminology at 169; more important, in those states proportionality review functions as a check against the arbitrary imposition of the death penalty.
    The experience of other states is instructive, if only because it demonstrates the diverse responses to questions about the conduct of proportionality review. For example, the propriety of courts utilizing quantitative methods has been vigorously debated. Compare Washington v. Pirtle, 904 P.2d 245, 277 (Wash. 1995) (noting that quantitative approach -- comparing number of aggravating circumstances, victims and prior convictions in similar cases -- "can point to areas of concern" and help court "to be as objective as possible"), cert. denied, 518 U.S. 1026, 116 S. Ct. 2568, 135 L. Ed.2d 1084 (1996), and Governor's Memorandum of Approval of 1995 N.Y. Laws, c. 1, reprinted in N.Y. Correct L. § 650 (approving consideration of statistical evidence in conducting proportionality review to determine whether race is "having a significant impact upon the imposition of the death penalty"), with Connecticut v. Webb, 680 A.2d 147, 209 (Conn. 1996) (rejecting New Jersey Supreme Court's statistical methods as unworkable attempt to "quantify the unquantifiable"),See footnote 1 and Bland, supra, 958 S.W. 2d at 665 (criticizing New Jersey Supreme Court's use of statistics as departure from jurisprudence of "individualized consideration"). Despite the concerns expressed by some courts about these methods, several states remain committed to a form of quantitative proportionality review to detect possible racial bias. See N.Y. Crim. Proc. Law § 470.30 (requiring proportionality review if request based on race of defendant or victim); Connecticut v. Cobb, 663 A.2d 948, 961-62 (Conn. 1995) (recognizing statutory basis for statistical claim of racial disparity in imposition of death penalty);See footnote 2 Washington v. Gerry, 888 P.2d 1105, 1154 (Wash.) (utilizing proportionality review to examine patterns in death sentencing based on race), cert. denied, 516 U.S. 843, 116 S. Ct. 131, 133 L. Ed.2d 79 (1995). Yet, statistical claims of racial bias in the administration of the death penalty present legal and methodological issues of exceptional complexity. We keep in mind the dialogue engendered by these difficult questions when considering how we might answer them ourselves.
    We turn now to our own experience in applying proportionality review in capital cases.

     C.    Proportionality Review in New Jersey

    When the New Jersey Legislature reintroduced the death penalty in 1982, it too substantially incorporated the procedural safeguards in the Georgia law sustained by the United States Supreme Court in Gregg, including the provision for proportionality review. See State v. Ramseur, 106 N.J. 123, 202-03 (1987). The New Jersey Capital Punishment Act, L. 1982,
c. 111 (codified at N.J.S.A. 2C:11-3), like the Georgia statute, called for a determination by this Court on "[e]very judgment of conviction which results in a sentence of death . . . . whether the sentence is disproportionate to the penalty imposed in similar cases, considering both the crime and the defendant," N.J.S.A. 2C:11-3e. Later, the Senate Judiciary Committee explained that, at the time the Act was passed by the State Legislature, "it was thought that the United States Supreme Court would not uphold a capital punishment law that did not contain such a 'proportionality review'" provision. Senate Judiciary Committee, Statement to Senate Bill No. 950 (L. 1985, c. 178).
    As enacted in 1982, the Capital Punishment Act required proportionality review, but did not describe the manner in which it was to be conducted or limit the "universe" of similar cases to be used for comparison purposes. In response to Pulley, however, the New Jersey Legislature amended N.J.S.A. 2C:11-3e to abolish mandatory proportionality review and to require instead that defendants request such review by this Court. L. 1985, c. 178. Then, in 1992, the proportionality review provision of N.J.S.A. 2C:11-3e was amended yet again to define the universe of "similar" cases to be compared to defendant's case as those "in which a sentence of death has been imposed." L. 1992, c. 5. This amendment became effective on May 12, 1992, L. 1992, c. 5, and will, if ultimately determined to be valid, limit the scope of proportionality review undertaken by this Court since Marshall II.
    In Ramseur, we explained that the development of "a procedure of review . . . [would] be an evolving process," requiring the advice of "criminal justice experts . . . [and] experts from disciplines outside the law." 106 N.J. at 328.
Our view of the fundamental purpose of proportionality review would guide this process:

            Proportionality review has a function entirely unique among the review proceedings in a capital proceeding. Proportionality review, in the context of a capital sentencing scheme, is not appellate review to ensure that the aggravating factors outweigh beyond a reasonable doubt all the mitigating factors, L. 1985, c. 178, or to determine if the death sentence is disproportionate to the crime in violation of the ban against cruel and unusual punishment. That death is not disproportionate in the sense of being a cruel and unusual punishment is presumed by the nature of the review. Pulley, supra, 465 U.S. at 43, 104 S. Ct. at 875, 79 L. Ed. 2d at 36. Rather, the purpose of review here is "of a different sort. . . . It purports to inquire instead whether the penalty is nonetheless unacceptable in a particular case because disproportionate to the punishment imposed on others convicted of the same crime."

        [Id. at 326 (quoting Pulley, supra, 465 U.S. at 43, 104 S. Ct. at 875, 79 L. Ed. 2d at 36).]

Therefore, when we conduct a proportionality review, we ask whether the "punishment fits the criminal," Marshall II, supra, 130 N.J. at 129, so as "to ensure that the death penalty is being administered in a rational, non-arbitrary, and evenhanded manner, fairly and with reasonable consistency," id. at 131.
    Ramseur also explained that proportionality review provides a mechanism by which death sentences may be monitored, "to prevent any impermissible discrimination in imposing the death penalty." 106 N.J. at 327. In Marshall II, we spoke of the "unique" commitment of the people of New Jersey "to the elimination of racial discrimination." 130 N.J. at 207. Today, as then, we believe that "[t]o countenance racial discrimination in capital sentencing would mock that tradition and our own constitutional guarantee of equal protection of the laws under New Jersey Constitution Article I, paragraph 1." Ibid. Comparison of like cases presents an opportunity for the Court to monitor whether impermissible factors are present in the capital sentencing system.
    Marshall II describes in detail the creation of a database and the sorting processes we have used as a basis for comparison of similar cases. Id. at 141-45. We have substantially relied on the Final Report of our first Special Master, David C. Baldus, Death Penalty Proportionality Review Project, Final Report to the New Jersey Supreme Court (Sept. 24, 1991) (Final Report). As outlined in Marshall II, supra, 130 N.J. at 152-59, and followed in our subsequent proportionality review cases, we conduct a frequency analysis using statistical methods and a precedent-seeking review consisting of case-by-case analyses of comparative culpability. State v. Bey, 137 N.J. 334, 350 (1994) (Bey IV), cert. denied, 513 U.S. 1164, 115 S. Ct. 1131, 130 L. Ed.2d 1093 (1995); State v. Martini, 139 N.J. 3, 28 (1994) (Martini II), cert. denied, 516 U.S. 875, 116 S. Ct. 203, 133 L. Ed.2d 137 (1995); State v. DiFrisco, 142 N.J. 148, 165-66 (1995) (DiFrisco III), cert. denied, 516 U.S. 1129, 116 S. Ct. 949, 133 L. Ed.2d 873 (1996). These methods compare the case at bar to other cases that have been found to have either similar fact patterns or similar levels of culpability and are used to determine whether the sentence imposed on the defendant in the case at bar is disproportionate to the sentences imposed in those similar cases.     More specifically, frequency analysis is a statistical approach that determines in three ways which cases have similar levels of culpability: (1) the salient-factors test; (2) the numerical-preponderance-of-aggravating-and-mitigating-factors test; and (3) the index-of-outcomes test. Bey IV, supra, 137 N.J. at 350-51. The salient-factors test "defines 'similar cases in terms of factual comparability,'" while the numerical-preponderance-of-aggravating-and-mitigating-factors test compares the raw number of those factors in each case. Marshall II, supra, 130 N.J. at 146-47 (citations omitted). The
index-of-outcomes test is a regression analysis that determines the culpability levels of defendants "'as measured by the presence or absence in the cases of [statutory and non-statutory aggravating and mitigating] factors that appear to influence prosecutorial and jury decision-making.'" Id. at 147-48 (citation omitted). Precedent-seeking review, on the other
hand, compares all relevant statutory and nonstatutory aggravating and mitigating factors present in factually similar cases in order to determine defendant's criminal culpability,
or relative degree of deathworthiness. See DiFrisco III,
supra, 142 N.J. at 184-85.
    From the beginning, there has been extensive critical commentary by the Public Defender and Attorney General, along with alternative suggested approaches, on the frequency analysis methodologies accepted by the Court. We have considered that commentary and have chosen in each case to discuss the results
of our frequency tests despite their acknowledged deficiencies, with the caveat that ultimately our judgments about the proportionality of death sentences are unquantifiable.
Frequency review has always functioned as an adjunct to the detailed comparison of like cases that we undertake in precedent-seeking review and that, as judges, we are by training and experience best equipped to do.See footnote 3

The Constitutionality of N.J.S.A. 2C:11-3e As Amended

     A.    Pending Appeals

    In Marshall II, we determined that N.J.S.A. 2C:11-3e, as amended, would not apply to defendant's case because his appeal was pending at the time the amendment took effect on May 12, 1992. 130 N.J. at 119. Under the pre-1992 proportionality review provision of N.J.S.A. 2C:11-3e, we held that the appropriate "universe" from which to choose similar cases included not only all cases in which the death penalty had been imposed, or had been sought, but also "clearly death eligible homicides in which the prosecutor elected not to seek the death penalty." Id. at 137. We chose the larger universe in order to consider the possibility that a jury had imposed a disproportionate sentence, id. at 133-34, or that a prosecutor had misused his or her discretion, id. at 134, and, in order to prevent "'any impermissible discrimination in imposing the death penalty,'" id. at 135 (quoting Ramseur, supra, 106 N.J. at 327).     In the three cases following Marshall II, we continued to make use of a universe of death-eligible homicides. DiFrisco III, supra, 142 N.J. at 162-63; Martini II, supra, 139 N.J. at 23; Bey IV, supra, 137 N.J. at 343-44. In each of these cases, the 1992 statutory amendment limiting our review to death-sentenced cases was inapplicable because the appeals in these cases were pending as of the effective date of the amendment. DiFrisco III, supra, 142 N.J. at 163;See footnote 4 Martini II, supra, 139 N.J. at 23; Bey IV, supra, 137 N.J. at 343-44. In this case, defendant was not convicted until July 8, 1994, more than two years after the effective date of the 1992 statutory amendment.See footnote 5 For that reason, we now consider whether we must conform our proportionality review methodology to the 1992 amendment thereby limiting proportionality review "to a comparison of similar cases in which a sentence of death has been imposed." N.J.S.A. 2C:11-3e.

    B.    The Supreme Court's Appellate Review Function
    Comparing a death-sentenced defendant's case to other similar cases enables us to consider whether the death penalty has been imposed arbitrarily on the defendant. Moreover, proportionality review may be the only mechanism that permits system-wide evaluation of both prosecutorial and jury decision making so as to determine whether there has been racial or other impermissible discrimination. These considerations weigh heavily when a life is at stake. It is a mark of our humanity that, no matter how heinous the crime, we focus, finally, on individual defendants, their acts and their lives. We seek to administer the most extreme penalty in a fair and consistent manner by comparing the defendant to others who have committed like crimes, thereby to decide whether there is a societal consensus that the defendant before us should be put to death. In our constitutional system, this Court is entrusted with that ultimate decision.
    The source of the Supreme Court's appellate review authority can be found in Article VI, Section 2, Paragraph 2 of the 1947 Constitution: "The Supreme Court shall exercise appellate jurisdiction in the last resort in all causes provided in this Constitution." As defined by Article VI, Section 5, Paragraph 1, the Court hears appeals:

            (a) In causes determined by the appellate division of the Superior Court involving a question arising under the Constitution of the United States or this State;

            (b) In causes where there is a dissent in the Appellate Division of the Superior Court;

            (c) In capital causes;

            (d) On certification by the Supreme Court to the Superior Court and, where provided by rules of the Supreme Court, to the inferior courts; and

            (e) In such causes as may be provided by law.

We derive from this grant of power, in both its discretionary and mandatory forms, our core function as this State's highest
Court -- the power of appellate review.
    In State v. Laws, 51 N.J. 494 (1968), Justice Jacobs described "the scope of this Court's reviewing authority" under the 1947 Constitution:

        That organic document purposefully modernized and greatly strengthened our judicial system. In the process it vested this Court with wide judicial power, perhaps more sweeping than that granted to any other court of last resort, and all to the end that it would be in a fair position to ensure that justice is truly and equally done.

See also Hager v. Weber, 7 N.J. 201, 205 (1951) (holding appellate review by Supreme Court "is a remedial procedure secured against legislative interference" by various provisions of State Constitution).
    Justice Jacobs's understanding of this Court's broad appellate power echoes Governor Driscoll's speech to the Committee on the Judiciary at the 1947 Constitutional Convention. Governor Driscoll had a vision of an integrated court system administered through a centralized authority and capable of "achieving the degree of uniformity [in dispensing justice] that is so highly desirable in a republic." Alfred E. Driscoll, Address to Committee on the Judiciary, in 4 State of New Jersey Constitutional Convention of 1947 427, 435 (Sidney Goldmann & Herman Crystal eds., 1951) (Driscoll Address). He told the Committee on the Judiciary:

            It is, as you know, the courts that have traditionally been the guardians of our constitutions, to whom the meanest citizen may appeal for protection against a wayward executive or a capricious legislature. Without independent courts, the whole republican system must surely fail. Our primary, our basic purpose in the drafting of a new Constitution is to secure beyond any question a strong, competent, easily functioning, but always independent, judiciary, and, therefore, in a position to curb any tendency on the part of the other two branches of government to exceed their constitutional authority.

            It was Hamilton who quoted Montesquieu: "There is no liberty if the powers of judging be not separate from the legislative and executive powers." "The complete independence of the courts of justice is         peculiarly essential in a limited constitution," Hamilton added.

    Governor Driscoll's call did not go unheeded. Students of New Jersey constitutional history, and particularly of the Judicial Article, often point to the extraordinary accomplishments of the 1947 Constitution in recasting an antiquated collection of multiple overlapping courts into a modern efficient judiciary. Leon S. Milmed, Introduction to the New Jersey Constitution of 1947 1, 12 (1954). The Report of the Committee on the Judiciary, submitted to the Convention on July 24, 1947, recommended simplifying and streamlining the court system, including centralizing administrative responsibility, merging the Courts of Law and Equity, and reducing the multiple functions of appellate court judges as well as multiple appeals at the intermediate appellate court level. See Committee on the Judiciary, Report and Proposal (Aug. 26, 1947), in 2 State of New Jersey Constitutional Convention of 1947, supra, 1180, 1182-83 (Committee Report). Although the thrust of the Committee's recommendations was administrative in nature, we must not forget that the purpose was to create an efficient vehicle in which judges could carry out their most basic function -- deciding cases -- and in which all New Jersey citizens would, in Governor Driscoll's words, be "equal[] before the law." Driscoll Address, supra, at 434.     
    Broad powers were granted to the Supreme Court at the same time that the Court's as-of-right jurisdiction was limited. Committee Report, supra, at 1184. The Co