Appellant James Rogers challenges the trial court’s order finding that he waived his request for a jury trial on the issue of mental retardation pursuant to Fleming v. Zant, 259 Ga. 687 (386 SE2d 339) (1989). Because we hold that a defendant who was tried for a capital crime prior to July 1, 1988 cannot waive his request for a hearing to determine whether he is mentally retarded once a court finds sufficient credible evidence of mental retardation to create an issue for a jury, we reverse and remand to the trial court.
1. Rogers was convicted and sentenced to death for the murder of Grace Perry.1 His convictions and sentence were affirmed by this Court on direct appeal. See Rogers v. State, 256 Ga. 139 (344 SE2d 644) (1986). Following the procedure outlined by this Court in Fleming, in 1994 Rogers initiated state habeas corpus proceedings by filing a petition seeking a jury trial on the issue of mental retardation. At a hearing on his petition, Rogers presented evidence of mental retardation, including affidavits of mental health experts who diagnosed him as mentally retarded and suffering from significant neuro*68logical impairment.2 In a May 1995 order the habeas corpus court concluded that a genuine issue of fact existed regarding Rogers’ mental retardation and granted the writ for the purpose of conducting a Fleming trial.
On return to the trial court, counsel was appointed to represent Rogers in the jury trial on the issue of mental retardation. In February 2001, just before the scheduled hearing, Rogers wrote a letter to the judge asking for the dismissal of the mental retardation trial. The court held a hearing on Rogers’ request during which Rogers stated to the court that he was not mentally retarded. The following day the trial court entered its order finding Rogers “knowingly and voluntarily waive [d] his right to a jury trial on this issue of mental retardation.”
In March 2001, with new counsel, Rogers filed a “Consolidated Motion to Vacate Dismissal of Mental Retardation Trial, To Withdraw Waiver, To Reinstate Mental Retardation Trial And/Or Notice of Appeal to Dismissal Order.” An attachment to the motion contained a handwritten note from Rogers stating, “I want to have my case back in court. I want to have the court rule on my innocence. I want the court to rule on my IQ.” The trial court conducted a hearing on this motion in June 2001. Before the court ruled on the motion, however, Rogers mailed another letter to the court stating, “I do not want the mental retardation trial and I would like it dismissed.” On July 24, 2001, the trial court entered an order denying the motion and holding that Rogers waived a jury trial on the issue of mental retardation. Rogers’ direct appeal of that order was dismissed as untimely. He thereafter filed a motion for and was granted an out-of-time appeal. On appeal, Rogers challenges the trial court’s order finding that he waived his right to a trial on the issue of mental retardation.
2. Under both the Georgia and United States Constitutions, a criminal defendant may not be put to death if he is found to be mentally retarded. See Atkins v. Virginia, 536 U. S. 304 (IV) (122 SC 2242, 153 LE2d 335) (2002); Fleming, supra, 259 Ga. at 690. Accordingly, where a defendant’s mental capacity is challenged or otherwise appears to be in question, the Georgia and United States Constitutions require adjudication of the defendant’s mental capacity in order to determine his or her eligibility for a death sentence. In Georgia, the procedure to be followed in making such a determination depends upon the date of trial. For those defendants tried after July 1, 1988, OCGA § 17-7-131 permits them to contend that they were mentally *69retarded at the time of the crime and to present evidence of such mental retardation to the fact finder. In capital cases, the fact finder is then required to determine during the guilt-innocence phase of trial whether the defendant is guilty but mentally retarded. OCGA § 17-7-131 (j). Under this statutory scheme, where the trier of fact makes a specific finding that the defendant is mentally retarded, the defendant cannot be executed but must instead be sentenced to life imprisonment.3 Id.
A defendant tried prior to July 1, 1988, for whom no judicial determination on mental retardation will have been made, may choose to raise the issue of his or her mental retardation by filing a petition for habeas corpus and presenting sufficient credible evidence, including at least one expert diagnosis of mental retardation, to create a genuine issue regarding retardation. Fleming, supra at 691 (4).
If, after examining the evidence, the habeas corpus court finds that there is a genuine issue, a writ shall be granted for the limited purpose of conducting a trial on the issue of retardation only. This trial shall be held in the court in which the original trial was conducted. Petitioner shall be entitled to a full evidentiary hearing on the issue of retardation. The determination shall be made by a jury using the definition of retardation enunciated in the statute. See OCGA § 17-7-131 (a) (3).
Id. The Fleming trial allows petitioners to establish judicially whether mental retardation is a genuine issue and obtain resolution of that issue through a jury trial. Once a petitioner carries his burden of proof in the habeas corpus court of creating a genuine issue regarding his mental retardation, the issue must be thoroughly reviewed and passed upon. Id. At such point in the proceedings, the issue is no longer subject to waiver by a petitioner. This holding is consistent with our opinion in Fleming and the national and statewide consensus against the execution of mentally retarded persons.
3. In this case, pursuant to our decision in Fleming, Rogers chose to initiate habeas corpus proceedings by filing a petition alleging he is mentally retarded. He thereafter adduced sufficient credible evidence of such retardation to authorize the habeas corpus court to grant the writ and remand to the superior court for a full evidentiary *70hearing on the issue of his retardation. Despite the habeas corpus court’s findings and this Court’s mandate in Fleming that a jury trial be held on the petitioner’s retardation when his mental capacity is properly placed in issue, the trial court nevertheless concluded that Rogers could voluntarily waive his right to a trial on retardation. We reject this holding. Once a habeas corpus court finds a petitioner has adduced sufficient credible evidence of mental retardation to create an issue for a jury, it is the duty of the trial court to conduct a jury trial on the issue of mental retardation pursuant to the procedures established in Fleming.4 Because the trial court in this case failed to conduct a jury trial on the issue of Rogers’ mental retardation, we reverse and remand to the trial court for proceedings consistent with this opinion.
Judgment reversed and remanded.
All the Justices concur, except Carley, J., who dissents.Rogers was convicted in 1982 for the murder of Perry and aggravated assault of Edith Polston and sentenced to death. On direct appeal, .this Court reversed his convictions and sentences based on the unconstitutional composition of the Floyd County grand jury. See Devier v. State, 250 Ga. 652 (1) (300 SE2d 490) (1983). After a second trial, Rogers was again found guilty of murder and aggravated assault and sentenced to death for the murder conviction and a consecutive ten-year sentence for aggravated assault.
Rogers also provided affidavits of teachers, former attorneys, and family members supporting the diagnosis of mental retardation.
Because Rogers was tried prior to the effective date of OCGA § 17-7-131, we do not here reach the issue of whether a defendant who has contended pursuant to OCGA § 17-7-131 that he is mentally retarded may thereafter waive a determination of that issue by the fact finder.
We reject the State’s contention that the trial court properly resolved the mental retardation issue by finding in its dismissal order that Rogers is not mentally retarded. The State’s argument ignores the plain language in Fleming requiring that the determination of whether a defendant is mentally retarded be decided by a jury.