concurring:
I specially concur in the judgment. I fully agree with the constitutional principle espoused by the plurality that the “qualitatively unique and irretrievably final nature of the death penalty” mandates an enhanced level of certainty and reliability in the jury’s decision to impose that penalty. Plurality op. at 843. The very reason for codifying into law a list of aggravating and mitigating factors or circumstances is to ensure certainty and reliability by requiring the sentencing jury, after giving due consideration to all relevant mitigating factors or circumstances supportive of a life sentence in making its determination, to resolve the issue of punishment on the basis of objective statutory criteria that narrow the class of persons eligible for a death sentence. The present statutory scheme, however, permits the jury to impose a death sentence when the jury is not satisfied beyond a reasonable doubt that any proven statutory aggravating factor, the existence of which is a statutory prerequisite to any consideration of a sentence of death, actually outweighs the mitigating evidence supportive of a life sentence. The certainty and reliability essential to a constitutionally valid death sentence lead me to conclude that this statutory scheme cannot be squared with the Cruel and Unusual Punishment Clause and the Due Process Clause of the Colorado Constitution. Colo. Const, art. II, §§ 20 & 25.
I.
Effective July 1, 1988, the General Assembly amended the statutory capital sentencing scheme in several particulars. Ch. 114, sec. 5, 1988 Colo.Sess.Laws 673-75. The most critical aspect of the 1988 amendment is the elimination of the previously existing fourth step in the deliberative process, which provided that if the jury finds that any mitigating factors do not outweigh any proven aggravating factor or factors, it shall determine whether the defendant “should be sentenced to death or life imprisonment,” § 16-ll-103(2)(a)(III), 8A C.R.S. (1986). The 1988 statute collapses the previous third and fourth steps into one phase by providing as follows:
In the event that the jury finds that at least one statutory aggravating factor has been proved beyond a reasonable doubt, and that there are insufficient statutory mitigating factors or other mitigating circumstances to outweigh any statutory aggravating factor or factors that were proved and any other aggravating circumstances that were proved, the jury shall return a sentence of death.
Section 16-ll-103(2)(b)(III), 8A C.R.S. (1990 Supp.).
In People v. Tenneson, 788 P.2d 786 (Colo.1990), we considered the pre-1988 version of the statutory scheme applicable to the weighing of aggravating and mitigating factors. As expressed in section 16-11-103(2)(a)(II), 8A C.R.S. (1986), the weighing process required the jury to determine “[wjhether sufficient mitigating factors exist which outweigh any aggravating factor or factors found to exist.” The present statute under consideration substantially tracks this pre-1988 version by requiring the jury to consider whether “sufficient statutory mitigating factors or other mitigating circumstances exist which outweigh any statutory aggravating factor or factors and other aggravating circumstances.” Section 16-ll-103(2)(a)(II), 8A C.R.S. (1990 Supp.). In Tenneson, we construed the statutory standard applicable to *848the weighing process in the third step in the deliberative process to mean that each juror must be convinced beyond a reasonable doubt that “the mitigating factors, if any, do not weigh more heavily in the balance than the proven statutory aggravating factors.” 788 P.2d at 792. We also held that the then existing statutory scheme required the jurors to separately determine in the fourth step of the deliberative process whether “they unanimously agreed that death was the appropriate punishment beyond a reasonable doubt.” Tenneson, 788 P.2d at 796.
I dissented in part in Tenneson because I believed, as I continue to believe, that the Tenneson formulation of the “proof beyond a reasonable doubt” standard in terms of mitigation not outweighing aggravation does not go far enough in ensuring the certainty and reliability constitutionally essential for a valid sentence of death. 788 P.2d at 805-08 (Quinn, J., dissenting in part). I am satisfied that the constitutional prerequisites of certainty and reliability implicit in the Cruel and Unusual Punishment and Due Process Clauses of the Colorado Constitution mandate that the “proof beyond a reasonable doubt standard” applicable to the third step in the deliberative process be formulated in terms of the jury being convinced beyond a reasonable doubt that any proven statutory aggravating factors or circumstances actually outweigh the mitigating factors or circumstances before a valid sentence of death can be imposed. The necessity for such a procedure finds its source in the fact that the interest in life itself is of such transcendent importance that it requires a procedural regularity far beyond that applicable to the ordinary criminal proceeding. See State v. Biegenwald, 106 N.J. 13, 524 A.2d 130, 155-56 (1987).
The “mitigation not outweighing aggravation” standard sanctioned by section 16-ll-103(2)(b)(III) results in requiring the imposition of a death sentence under circumstances where the evidence of aggravation is no more than evenly balanced with any mitigating evidence and also where the jury harbors a serious doubt about the appropriateness of a death sentence due to the existence of substantial mitigating evidence calling for leniency but not such as to outweigh the evidence of aggravation. The present statutory scheme thus countenances, indeed requires, a verdict of death notwithstanding the existence of a level of jury uncertainty in the deliberative process that would prevent the same jury from conscientiously returning a guilty verdict in a trial involving a minor criminal offense. In my view, any death sentence imposed under the present statutory scheme would be substantially devoid of the certainty and reliability indispensable to a rational system of justice concerned with preventing the arbitrary and capricious imposition of capital punishment. I would hold, for reasons set forth in my partial dissent in Ten-neson, 788 P.2d at 805-08, that the Cruel and Unusual Punishment and the Due Process Clauses of the Colorado Constitution require the prosecution to bear the burden of persuading the jury beyond a reasonable doubt that any proven statutory aggravating factor or circumstance outweighs any mitigating evidence before the jury can impose a sentence of death.
II.
In the absence of requiring that the jury be convinced beyond a reasonable doubt that the aggravation outweighs mitigation, I agree with the plurality that the certainty and reliability essential to a constitutionally valid death sentence militate in favor of a fourth step in the deliberative process whereby the jury is required to separately and independently consider the appropriateness of the death sentence in the particular case under consideration. It has been observed, and quite cogently so, that nowhere in the law is the interplay of substantive statutory standards and procedural rules more critical than in the penalty phase of a capital case:
The substantive standards must be “objective standards to guide, regularize, and make rationally reviewable the process for imposing a sentence of death.” [Woodson v. North Carolina, 428 U.S. 280, 303, 96 S.Ct. 2978, 2990, 49 L.Ed.2d 944 (1976)]. It makes no difference, *849however, how rational and discriminating the substantive standards are, if the procedural rules which implement those standards do not provide an effective mechanism for their faithful implementation. Even if Solomon-like wisdom were available in framing objective standards, their whole purpose could be thwarted if the governing procedural rules allowed the sentencing body to impose the death penalty in the face of evidence which creates a reasonable or substantial doubt as to the appropriateness of that penalty.
State v. Wood, 648 P.2d 71, 81 (Utah), cert. denied, Wood v. Utah, 459 U.S. 988, 103 S.Ct. 341, 74 L.Ed.2d 383 (1982).
The fourth step, while perhaps not adequate by itself to offset the uncertainty and unreliability fostered by the constitutionally infirm standard of proof applicable to the third step of the deliberative process, nonetheless offers some protection against the imposition of a death sentence when the jury is not convinced to a moral certainty that the evidence of aggravation actually outweighs the evidence of mitigation. The Cruel and Unusual Punishment and Due Process Clauses of the Colorado Constitution require the fourth step if for no other reason than to safeguard against the arbitrary and capricious imposition of a death sentence under a statutory scheme that countenances such a penalty even though the evidence of aggravation and mitigation is in a state of equipoise.
For the above reasons, I specially concur in the judgment invalidating section 16-11-103, 8A C.R.S. (1986 & 1990 Supp.).