Appellant Thomas Hinson was convicted of trafficking in marijuana and sentenced to twenty-five years in prison. We affirm appellant’s conviction, but remand to permit appellant to move before the circuit court for a new trial.
Prior to trial, appellant made a motion for disclosure of favorable evidence pursuant to Brady v. Maryland, 373 U. S. 83, 83 S. Ct. 1194, 10 L. Ed. (2d) 215 (1963). He renewed his motion at the commencement of the trial. The State disclosed nothing regarding a promise of immunity with prosecution witness Johnophine Stalls.
In response to questioning by the solicitor, Mrs. Stalls testified she had not been promised anything for her testimony against appellant. She confirmed this under cross examination by appellant’s counsel. In closing argument, the solicitor attempted to bolster the credibility of Mrs. Stalls by suggesting she had willingly testified despite pending charges against her.
Moments after the verdict was returned, the solicitor advised the trial judge Mrs. Stalls would not be prosecuted. Following this statement, appellant renewed his motion for a new trial on the basis of the solicitor’s failure to disclose a promise of immunity made to Mrs. Stalls in exchange for her testimony. The trial judge failed to rule on the motion observing that Mrs. Stalls’ testimony “will speak for itself.”
Due process requires disclosure by the prosecution upon motion of the defendant, of evidence which would be favorable to the accused and which is material to guilt or punishment. Brady v. Maryland, supra. Evidence which may be used to impeach a witness’s credibility is favorable to an accused under Brady. Giglio v. United States, 405 U. S. 150, 92 S. Ct. 763, 31 L. Ed. (2d) 104 (1972).
*408“When the reliability of a given witness may well be determinative of guilt or innocence,” nondisclosure of a promise of immunity made to that witness is a violation of due process. Giglio v. United States, 92 S. Ct. at 154, citing Napue v. Illinois, 360 U. S. 264, 79 S. Ct. 1173, 3 L. Ed. (2d) 1217 (1959). A new trial will be required when the non-disclosed evidence is material. Brady v. Maryland, supra. Evidence is material when there is a reasonable probability that the result of trial would have been different had the evidence been disclosed to the defense. United States v. Bagley, 473 U. S. 667, 105 S. Ct. 3375, 87 L. Ed. (2d) 481 (1985).
Appellant urges reversal of his conviction based on the nondisclosure of a promise of immunity made to Mrs. Stalls. While the record strongly suggests an undisclosed promise, it does not clearly show a promise existed. At most, the record reflects the solicitor’s unilateral decision not to prosecute. The time the decision was made, and Mrs. Stalls’ knowledge of the decision, if any, are left to speculation.
The procedural history of Giglio, supra, makes clear that a motion for a new trial is the proper vehicle for exploring these issues when the trial record does not fully reflect the circumstances surrounding the alleged promise.1 The trial court may determine, through testimony of Mrs. Stalls, the solicitor, and other parties with knowledge of the facts, the circumstances of the alleged promise. A decision can then be made on the basis of the facts as they are determined to be, not on the basis of speculation.
As noted, appellant made a motion for a new trial on the basis of a non-disclosure, but the trial judge failed to rule on the motion. We remand to allow appellant to renew this motion and to file supplemental documentation in support of his motion. Notwithstanding the provisions of Criminal Practice Rule 5, appellant shall have thirty (30) days from the date of this opinion to renew his motion in the trial court.
*409Appellant’s remaining exceptions are without merit, and his conviction is affirmed subject to the remand as set forth above.
Affirmed and remanded.
Gregory and Harwell, JJ., and Bruce Littlejohn, Acting Associate Justice, concur. Finney, J., dissents.While Giglio’s direct appeal from his conviction was pending, he moved in the district court for a new trial on the basis of the prosecution’s nondisclosure of a promise of immunity. The motion was denied. The United States Supreme Court reversed the denial of a new trial motion, not the conviction. 92 S. Ct. at 764.