JUSTICE O'CONNOR, concurring in part and concurring in the judgment.
Last Term, in Thompson v. Oklahoma, 487 U.S. 815, 857-858 (1988) (opinion concurring in judgment), I expressed the view that a criminal defendant who would have been tried as a juvenile under state law, but for the granting of a petition waiving juvenile court jurisdiction, may only be executed for a capital offense if the State's capital punishment statute specifies a minimum age at which the commission of a capital crime can lead to an offender's execution and the defendant had reached that minimum age at the time the crime was committed. As a threshold matter, I indicated that such specificity is not necessary to avoid constitutional problems if it is clear that no national consensus forbids the imposition of capital punishment for crimes committed at such an age. Id. at 857. Applying this two-part standard in Thompson, I concluded that Oklahoma's imposition of a death sentence on an individual who was 15 years old at the time he committed a capital offense should be set aside. Applying the same [p381] standard today, I conclude that the death sentences for capital murder imposed by Missouri and Kentucky on petitioners Wilkins and Stanford respectively should not be set aside, because it is sufficiently clear that no national consensus forbids the imposition of capital punishment on 16- or 17-year-old capital murderers.
In Thompson, I noted that
- [t]he most salient statistic that bears on this case is that every single American legislature that has expressly set a minimum age for capital punishment has set that age at 16 or above.
Id. at 849. It is this difference between Thompson and these cases, more than any other, that convinces me there is no national consensus forbidding the imposition of capital punishment for crimes committed at the age of 16 and older. See ante at 370-372. As the Court indicates, "a majority of the States that permit capital punishment authorize it for crimes committed at age 16 or above. . . ." Ante at 371. Three States, including Kentucky, have specifically set the minimum age for capital punishment at 16, see Ind.Code §35-50-2-3(b) (1988); Ky.Rev.Stat.Ann. §640.040(1) (Baldwin 1987); Nev.Rev.Stat. §176.025 (1987), and a fourth, Florida, clearly contemplates the imposition of capital punishment on 16-year-olds in its juvenile transfer statute, see Fla.Stat. §39.02(5)(c) (1987). Under these circumstances, unlike the "peculiar circumstances" at work in Thompson, I do not think it necessary to require a state legislature to specify that the commission of a capital crime can lead to the execution of a 16- or 17-year-old offender. Because it is sufficiently clear that today no national consensus forbids the imposition of capital punishment in these circumstances, "the implicit nature of the [Missouri] Legislature's decision [is] not . . . constitutionally problematic." 487 U.S. at 857. This is true, a fortiori, in the case of Kentucky, which has specified 16 as the minimum age for the imposition of the death penalty. The day may come when there is such general legislative rejection of the execution of 16- or 17-year-old capital murderers that a clear national [p382] consensus can be said to have developed. Because I do not believe that day has yet arrived, I concur in Parts I, II, III, and IV-A of the Court's opinion, and I concur in its judgment.
I am unable, however, to join the remainder of the plurality's opinion for reasons I stated in Thompson. Part V of the plurality's opinion "emphatically reject[s]," ante at 378, the suggestion that, beyond an assessment of the specific enactments of American legislatures, there remains a constitutional obligation imposed upon this Court to judge whether the "‘nexus between the punishment imposed and the defendant's blameworthiness'" is proportional. Thompson, supra at 853, quoting Enmund v. Florida, 458 U.S. 782, 825 (1982) (O'CONNOR, J., dissenting). Part IV-B of the plurality's opinion specifically rejects as irrelevant to Eighth Amendment considerations state statutes that distinguish juveniles from adults for a variety of other purposes. In my view, this Court does have a constitutional obligation to conduct proportionality analysis. See Penry v. Lynaugh, ante at 335-340; Tison v. Arizona, 481 U.S. 137, 155-158 (1987); Enmund, 458 U.S. at 797-801; id. at 825-826 (O'CONNOR, J., dissenting). In Thompson, I specifically identified age-based statutory classifications as "relevant to Eighth Amendment proportionality analysis." 487 U.S. at 854 (opinion concurring in judgment). Thus, although I do not believe that these particular cases can be resolved through proportionality analysis, see Thompson, supra, at 853-854, I reject the suggestion that the use of such analysis is improper as a matter of Eighth Amendment jurisprudence. Accordingly, I join all but Parts IV-B and V of the Court's opinion.