In 1987, Timothy Tyrone Foster was convicted and sentenced to death by a jury in Floyd County. We affirmed. Foster v. State, 258 Ga. 736 (374 SE2d 188) (1988) (cert. denied 109 SC 2110). Foster filed a petition for writ of habeas corpus in the superior court of Butts County, claiming, inter alia, that he is mentally retarded. According to the briefs filed in this case, the habeas court conducted a hearing on the retardation issue, determined that there was a “genuine issue” of retardation, and “remanded” the case to Floyd County for a jury trial on the issue of Foster’s alleged mental retardation, following the procedure set out in Fleming v. Zant, 259 Ga. 687 (4) (386 SE2d 339) (1989).
The case is now in this court on interlocutory appeal from the Floyd County Superior Court to resolve questions concerning the procedure to be followed at the mental-retardation trial.
1. In 1982, the legislature enacted a law creating, for the first time in this state, a verdict of guilty but mentally ill. Ga. L. 1982, p. 1476, codified at OCGA § 17-7-131. As originally defined, the verdict included not only mental illness, but also mental retardation. See, e.g., Spraggins v. State, 258 Ga. 32 (1) (364 SE2d 861) (1988) (quoting the statutory definition of “mental illness” and holding that Spraggins’ mental-retardation evidence entitled him “to jury instructions on the possible verdict of guilty but mentally ill.”) After Spraggins was decided, the legislature revised OCGA § 17-7-131 to split the former definition of “mentally ill” in two, now defining “mentally retarded” separately from “mentally ill,” see OCGA § 17-7-131 (a), and also providing explicitly that a defendant found guilty but mentally retarded may not be sentenced to death. OCGA § 17-7-131 (j).
The petitioner in Fleming v. Zant, supra, had been tried when Georgia law made no provision for an explicit jury finding of mental illness or retardation. The issue of Fleming’s possible mental retardation was not presented to his sentencing jury, and the jury did not know, for example, that on the basis of his mental retardation Fleming had been awarded social security disability benefits. In Division 3 *451of our opinion, we held that, based on the “consensus” in this state evidenced by the enactment of OCGA § 17-7-131 (j)> “the execution of the mentally retarded constitutes cruel and unusual punishment” under our Georgia Constitution. Id. at 690.
In Division 4 of Fleming, we outlined the procedure to be followed to give effect to our constitutional ruling in Division 3.
2. The district attorney argues that the “remand” procedure provided for in Fleming is unconstitutional, citing Newsome v. Black, 258 Ga. 787 (374 SE2d 733) (1989). Fleming, however, does not provide for a “remand.” It provides that “a writ shall be granted.” Fleming v. Zant, supra at 691. The proceedings in the Floyd Superior Court are separate proceedings following the grant of the writ by the habeas corpus court.
3. We agree with the attorney general that Warden Zant is not properly a party to the proceedings in the Floyd Superior Court. These proceedings are not a “continuation” of the habeas proceedings, but are separate proceedings in another county. Cf. Wiggins v. Lemley, 256 Ga. 152 (345 SE2d 584) (1986).
4. The purpose of the Fleming trial on the issue of retardation is to give the defendant essentially the same opportunity to litigate the issue of his mental retardation as he would have had if the case were tried today, with the benefit of the OCGA § 17-7-131 (j) death-penalty exclusion. Thus, we agree with the trial court that Foster has a right to appointed counsel for the retardation trial, as well as other rights that generally “would . . . have accrued to defendant because of his status as an accused during his initial trial.” Trial Court’s August 10, 1990 order at p. 9. However, we conclude, contrary to the trial court, that the mental-retardation trial jury should be selected in the same manner as a death-penalty criminal trial jury, including sequestration, and that while the state may cross-examine Foster if he testifies, the state may not call Foster for cross-examination in the first instance.
In addition, while we agree that the issue to be decided is whether or not Foster is mentally retarded, we disagree with the court’s pretrial order excluding all evidence of the underlying crime or Foster’s subsequent escape attempt. Although a trial court may exclude relevant evidence
if its probative value is substantially outweighed by the danger of unfair prejudice, confusion of the issues, or misleading the jury, or by considerations of undue delay, waste of time, or needless presentation of cumulative evidence,
Hicks v. State, 256 Ga. 715, 720-721 (352 SE2d 762) (1987), the pretrial ruling at issue sweeps too broadly and excludes evidence which *452may be highly probative of Foster’s mental abilities and materially relevant to the question of whether or not he is mentally retarded.
The pretrial order at issue here does not demonstrate that the trial court exercised its discretion to determine which evidence may be excluded because its relevance is outweighed by the danger of unfair prejudice. On remand, we direct the trial court to exercise its discretion in this regard.
5. Foster bears the burden of proving his mental retardation by a preponderance of the evidence. Fleming, supra at 691 (4). Spivey v. State, 253 Ga. 187, 188-189 (319 SE2d 420) (1984), holds otherwise as to the question of guilty but mentally ill under OCGA § 17-7-131 (c) (3). This case deals with retarded persons, not persons guilty but mentally ill. The issue in this case arises in the sentencing phase in death penalty cases. Guilty but mentally ill is a guilt or innocence issue. This case arises under our holding in Fleming. Because of these differences, it is not necessary here to reconsider the holding in Spivey.
6. The court did not err by granting the state’s motion for psychological evaluation of Foster. See Ingram v. State, 253 Ga. 622 (14) (323 SE2d 801) (1984).
Judgment affirmed in part, reversed in part and remanded.
All the Justices concur, except Smith, P. J., who dissents.