Warren Lee Hill, Jr. was sentenced to death in 1991 for the 1990 murder of a fellow prison inmate. Although Hill was tried three years after the effective date of OCGA § 17-7-131 (c) (3) and (j), which authorizes a verdict of guilty but mentally retarded and bars the execution of those found to be mentally retarded, no issue was raised by Hill regarding any alleged mental retardation at trial or on appeal. His conviction was affirmed by this Court. Hill v. State, 263 Ga. 37 (427 SE2d 770) (1993). Hill then filed a petition for writ of habeas corpus contending, inter alia, that his death sentence should be set aside on the ground that he is mentally retarded and thus should not be subject to execution;1 Hill also contended that trial counsel was ineffective for failing to investigate properly and raise his alleged mental retardation at trial. The State raised the defense of procedural default. The habeas court ruled that because the execution of a mentally retarded person violates the cruel and unusual punishment provision in the Georgia Constitution, as held in Fleming v. Zant, 259 Ga. 687, 690 (386 SE2d 339) (1989), the issue of mental retardation was not subject to procedural default. The habeas court then applied the standards set forth in Fleming v. Zant, which were promulgated to review mental retardation claims that arose in cases before the effective date of OCGA § 17-7-131, and found that Hill had presented sufficient credible evidence of mental retardation. The habeas court granted Hill a limited writ of habeas corpus for the purpose of conducting a jury trial on the issue of his mental retardation. The State appeals. For the reason set forth below, we reverse.
1. The State properly filed a direct appeal from the habeas court’s order. OCGA § 9-14-52 (c); see Zant v. Pitts, 263 Ga. 529 (436 SE2d 4) (1993).
2. The record reveals that appellee submitted affidavits directly to the habeas court after noticing his intent to rely upon the affidavits, see OCGA § 9-14-48 (c); the affidavits were disputed as to their merits by the State; and the habeas court has specifically ruled that it considered the affidavits in rendering its order. Therefore, we find no merit in the State’s argument that there was no evidence to support the habeas court’s order due to appellee’s failure, before the order was rendered, to formally tender the affidavits into evidence. The habeas court correctly granted appellee’s motion to complete the *303record on appeal by the addition of these affidavits. Contrary to the State’s argument, the record reflects that appellee sufficiently satisfied the statutory requirements for the admissibility of the affidavits, OCGA § 9-14-48 (c), and that the habeas court considered the State’s evidence before rendering its order.
3. The State contends the habeas court erred by holding that appellee’s mental retardation claim was not subject to procedural default.
(a) Initially, we hold that the State is not precluded from raising this argument. Our review of the record reveals that the State’s actions after the challenged ruling did not constitute a waiver by the State of its objection to the habeas court’s consideration of the mental retardation claim.
(b) In light of this Court’s holding that the execution of the mentally retarded constitutes cruel and unusual punishment under the Georgia Constitution, Fleming v. Zant, supra, 259 Ga. at 690, we find no error in the habeas court’s consideration of appellee’s claim of mental retardation.2 “In all cases habeas corpus relief shall be granted to avoid a miscarriage of justice.” OCGA § 9-14-48 (d). See also Black v. Hardin, 255 Ga. 239 (4) (336 SE2d 754) (1985) and Valenzuela v. Newsome, 253 Ga. 793 (4) (325 SE2d 370) (1985) (even absent a showing of cause and prejudice, the relief of the writ will remain available to avoid a miscarriage of justice where there has been a substantial denial of constitutional rights).
4. We reverse the habeas court’s ruling, however, because we hold that the standards set forth in Fleming v. Zant, supra, are not applicable to mental retardation claims raised in cases tried after the effective date of OCGA § 17-7-131 (c) (3) and (j). Our opinion in Fleming v. Zant expressly states that it “will not apply to defendants tried after the effective date of the statute.” Id., 259 Ga. at 691, n. 4. As discussed in Burgess v. State, 264 Ga. 777, 789 (36) (450 SE2d 680) (1994), this Court intended in Fleming v. Zant to give defendants tried before the effective date of the statute essentially the same opportunity to litigate the issue of mental retardation as those defendants would have had if the cases were tried with the benefit of the statute. In Burgess, supra at 790-791 (36), we declined to apply the standards in Fleming v. Zant to a defendant tried after the effective date of OCGA § 17-7-131 (c) (3) and (j) and drew attention to the *304different standards between the statute and the Fleming v. Zant opinion, specifically, the requirement in the statute that defendants carry the burden of proving their mental retardation beyond a reasonable doubt, as opposed to the holding in Fleming v. Zant, supra, 259 Ga. at 691 (4), that requires defendants to bear the burden of proving retardation by a preponderance of the evidence.3 To apply the Fleming v. Zant standards to a defendant tried after the effective date of OCGA § 17-7-131 (c) (3) and (j) would result in disparate treatment of such defendant.4 Given the explicit language in Fleming v. Zant prohibiting its application to defendants tried after the effective date of the statute, we hereby hold that the standards in Fleming v. Zant are not applicable to defendants like appellee who were tried when the statutory procedure established by our legislature to effectuate the public policy against the execution of mentally retarded defendants was in force. Upon considered review of this issue, we conclude that our holding to the contrary in Zant v. Pitts, supra, 263 Ga. at 529 (ineffective assistance of counsel claim) was misguided and we hereby overrule language to the contrary in that case.
Accordingly, this appeal is reversed and the case is remanded to the habeas court to consider appellee’s claim of mental retardation and to determine without intervention of jury whether appellee can establish, under the applicable standard set forth in OCGA § 17-7-131 (c) (3), that he is mentally retarded so as to invoke the bar against execution in OCGA § 17-7-131 (j). See generally Turpin v. Todd, 268 Ga. 820 (4), n. 45 (493 SE2d 900) (1997).
Judgment reversed and case remanded.
All the Justices concur, except Fletcher, P. J., who concurs specially and Carley and Thompson, JJ, who dissent.In support of his application, Hill adduced, inter alia, the affidavit of the psychologist who testified at the sentencing phase of Hill’s trial. The psychologist averred that his testimony at trial was based on inadequate information and explained in-depth why the IQ testing he originally used on Hill led to an inaccurate and misleading result.
A habeas court’s consideration of this claim affects only the sentencing phase of death penalty cases. To the extent claims of mental retardation are directly raised in habeas corpus proceedings to challenge such guilt-innocence phase issues as intent to commit the charged crime, such claims are waived by failure to assert mental retardation at trial. However, it may be possible to raise such claims indirectly as part of a claim of ineffective assistance of counsel.
We further note that OCGA § 17-7-131 (c) (3) applies in “all criminal trials in any of the courts of this state,” unlike Fleming v. Zant, which limits the defense to those defendants who have “presented sufficient credible evidence [of retardation], which must include at least one expert diagnosis of mental retardation.” Id., 259 Ga. at 691 (4).
A different result is not required by Zant v. Foster, 261 Ga. 450 (406 SE2d 74) (1991), with its language distinguishing between mentally retarded persons and persons guilty but mentally retarded, id. at (5), in that Zant a Foster was a case involving a habeas petitioner sentenced to death who had been tried before the effective date of OCGA § 17-7-131 (c) (3) and (j). We decline to extend its holding beyond the facts in that case.