
597 S.E.2d 195 (2004)
268 Va. 1
William Joseph BURNS, Petitioner,
v.
WARDEN OF THE SUSSEX I STATE PRISON, Respondent.
Record No. 020971.
Supreme Court of Virginia.
June 10, 2004.

Upon a Petition for a Writ of Habeas Corpus Upon a Rehearing.
In our initial consideration of Burns' petition for a writ of habeas corpus, we held that his claim of mental retardation was not frivolous. On October 28, 2003, we entered an order granting a portion of Burns' petition for a writ of habeas corpus and remanding the matter to the Circuit Court of Shenandoah County for a jury determination of Burns' mental retardation claim. We dismissed the remainder of the petition.
The Warden filed a motion for rehearing asserting that Burns was not entitled to a jury determination of his claim of mental retardation and requesting that we modify our prior order to direct the circuit court to resolve Burns' mental retardation claim without a jury. On February 6, 2004, we granted the Warden's motion for rehearing on that issue and vacated the portion of our October 28, 2003 order remanding Burns' mental retardation claim to the circuit court.
The procedures for determining mental retardation in capital murder trials held after April 29, 2003 are set out in Code §§ 19.2-264.3:1.1 and 19.2-264.3:1.2. These provisions allow a jury to decide the issue of a capital murder defendant's mental retardation. Code § 19.2-264.3:1.1(C).
Defendants whose capital murder trials had concluded as of April 29, 2003 may raise the issue of mental retardation through procedures established in Code § 8.01-654.2. This transitional statute created exceptions to the normal rules of appellate procedure and habeas corpus review. A capital murder defendant whose case was on direct appeal on April 29, 2003 could raise the issue of his mental retardation by a supplemental assignment of error. A capital murder defendant *196 who had concluded his direct appeal but whose state habeas corpus case was not final on April 29, 2003 could raise the issue of his mental retardation in his habeas corpus proceeding, if necessary by amending his petition.
Once the mental retardation issue is raised, Code § 8.01-654.2 directs that this Court
consider a claim raised under this section and if it determines that the claim is not frivolous, it shall remand the claim to the circuit court for a determination of mental retardation; otherwise the Supreme Court shall dismiss the petition. The provisions of §§ 19.2-264.3:1.1 and 19.2-264.3:1.2 shall govern a determination of mental retardation made pursuant 1to this section. If the claim is before the Supreme Court on direct appeal and is remanded to the circuit court and the case wherein the sentence of death was imposed was tried by a jury, the circuit court shall empanel a new jury for the sole purpose of making a determination of mental retardation.
The Warden interprets this statute as authorizing a jury determination of mental retardation only when a capital murder defendant raises the issue in this Court on direct appeal. This interpretation, he argues, is consistent with the fact that juries are not available in habeas corpus proceedings.
In reply, Burns posits that the plain language of the statute does not preclude a jury determination of mental retardation when a petitioner raises the issue in a habeas corpus proceeding. More importantly, Burns suggests, allowing some capital murder defendants a jury determination of mental retardation while denying that procedure to others amounts to disparate treatment that "would run afoul of state and federal guarantees of equal protection." Finally, Burns asserts that the rule in Ring v. Arizona, 536 U.S. 584, 122 S.Ct. 2428, 153 L.Ed.2d 556 (2002), and Apprendi v. New Jersey, 530 U.S. 466, 120 S.Ct. 2348, 147 L.Ed.2d 435 (2000), requires a jury determination of mental retardation because a factual finding that Burns is not mentally retarded is necessary to increase Burns' authorized punishment to death.
In construing this statute, we are guided by the principles that statutes are presumed to be constitutional, and, if possible, construed in a manner that avoids any constitutional infirmity. Yamaha Motor Corp. v. Quillian, 264 Va. 656, 665, 571 S.E.2d 122, 126-27 (2002).
Code § 8.01-654.2 permits all qualifying capital murder defendants to assert the constitutional ban on sentencing a retarded person to death. See Atkins v. Virginia, 536 U.S. 304, 321, 122 S.Ct. 2242, 153 L.Ed.2d 335 (2002). The threshold issue  whether the defendant is mentally retarded  is a factual one. The different procedures for resolving this factual issue that the Warden urges are based solely on whether a capital defendant happened to have his case on direct appeal or collateral attack on April 29, 2003. To assign the finding of this fact to the trial court for one group of qualifying defendants and to either a court or jury for another, as the Warden suggests, would treat similarly situated persons differently in violation of the Equal Protection Clause of the Fourteenth Amendment to the United States Constitution. City of Cleburne v. Cleburne Living Ctr., 473 U.S. 432, 439, 105 S.Ct. 3249, 87 L.Ed.2d 313 (1985).
This conclusion does not, however, mean that Code § 8.01-654.2 is unconstitutional. The statute directs that, if this Court concludes that a capital murder defendant's claim of mental retardation is not frivolous, whether on direct appeal or in a habeas corpus proceeding, we must remand the matter "to the circuit court" for a determination regarding mental retardation consistent with Code §§ 19.2-264.3:1.1 and 19.2-264.3:1.2. Nothing in that directive precludes the use of a jury to determine the issue of mental retardation if the issue arose in the context of a habeas corpus proceeding.
Finally, we reject the Warden's concerns that allowing a jury to determine the issue of mental retardation in a habeas corpus proceeding would cause "confusion and unnecessary litigation" over the appropriate procedures and would imply that this Court has "embrac[ed] a new right to jury determinations *197 of issues of fact in collateral actions that would unsettle centuries of Anglo-American jurisprudence." As we note above, Code § 8.01-654.2 is a transitional statute that the General Assembly enacted to address the rights of a limited number of capital murder defendants, and our holding is strictly a determination of the scope of Code § 8.01-654.2. That statute alters the normal proceedings applicable both to direct appeals and to habeas corpus proceedings in a very limited number of cases. Neither the statute nor this decision in any way alters our traditional habeas corpus rules.
For the stated reasons, we reinstate that portion of our October 28, 2003 order providing a limited grant of the petition for a writ of habeas corpus and remanding the case to the Circuit Court of Shenandoah County for a jury determination of Burns' claim of mental retardation in accord with Code §§ 8.01-654.2, 18.2-10, 19.2-175, 19.2-264.3:1, 19.2-264.3:1.1, 19.2-264.3:1.2, 19.2-264.3:3, and 19.2-264.4.
This order shall be published in the Virginia Reports.
Justice KINSER, dissenting.
I conclude that the petitioner failed to present a non-frivolous claim of mental retardation and is therefore not entitled to any further proceeding on that issue. See Code § 8.01-654.2. For that reason, I respectfully dissent.
