
511 S.E.2d 923 (1999)
236 Ga. App. 359
KENNEY
v.
The STATE.
No. A98A2340.
Court of Appeals of Georgia.
February 9, 1999.
*924 Paul J. McCord, Atlanta, for appellant.
J. Tom Morgan, District Attorney, Jeanne M. Canavan, Barbara B. Conroy, Assistant District Attorneys, for appellee.
BARNES, Judge.
A jury convicted Joshua Kenney of two counts of armed robbery. On appeal, Kenney challenges the sufficiency of the evidence against him, the constitutionality of his mandatory 15-year sentence, and several evidentiary rulings. We affirm the convictions.
Construed in favor of the jury's verdict, the evidence shows that two tourists were riding a MARTA train headed east from the Five Points station. The robber held a gun to one victim's face, screamed at him and took his wallet, then took his companion's wallet. The robber left the car with another young man who had been standing nearby.
A few minutes later, a MARTA bus driver flagged down a city police officer, who had noticed two young men running, and reported to the city officer that MARTA officers were pursuing two men. The police officer quickly located and held the two men while a MARTA officer retraced their tracks and recovered a gun at the base of a nearby bush. A witness from the train identified Joshua Kenney as the gunman. One of the victims positively identified Sirajuddin Qadir as the "lookout,"[1] and Qadir gave police a written statement that also identified Kenney as the gunman.
1. Kenney argues that the evidence was insufficient to convict him, asserting that the only evidence implicating him in the robberies was the uncorroborated testimony of Qadir. Thus, he argues, his convictions should be overturned pursuant to OCGA § 24-4-8. However, a former MARTA detective testified without objection that a witness to the robbery gave a statement positively identifying Kenney as the gunman. This testimony corroborates Qadir's testimony, and whether it was sufficient for a conviction was for the jury to determine. See Slaughter v. State, 227 Ga.App. 739, 490 S.E.2d 399 (1997); Moore v. State, 224 Ga. *925 App. 797, 481 S.E.2d 892 (1997). With that corroboration, the evidence was sufficient for a rational trier of fact to find Kenney guilty of two counts of armed robbery beyond a reasonable doubt. Jackson v. Virginia, 443 U.S. 307, 99 S.Ct. 2781, 61 L.Ed.2d 560 (1979).
2. Kenney contends that the admission of a res gestae statement violated his right under the Sixth Amendment of the United States Constitution to confront his accuser. However, we find no merit in this contention, as both this Court and the United States Supreme Court have specifically rejected this argument. See White v. Illinois, 502 U.S. 346, 112 S.Ct. 736, 116 L.Ed.2d 848 (1992); Barnett v. State, 211 Ga.App. 651, 440 S.E.2d 247 (1994). Further, despite Kenney's contention to the contrary, Georgia law has never required proof of the declarant's unavailability to admit res gestae. See Stovall v. State, 216 Ga.App. 138, 453 S.E.2d 110 (1995).
3. Kenney argues that his trial counsel should have been allowed to ask Qadir, who had been convicted but not sentenced, the minimum amount of time he could serve for armed robbery. The trial court initially told defense counsel he could not question Qadir at all about his possible penalty, but later advised counsel that he could ask Qadir only about his possible maximum, not minimum, sentence. We find no abuse of discretion in the trial court's limitation of defense counsel's cross-examination. See Wand v. State, 230 Ga.App. 460, 496 S.E.2d 771 (1998); Cantrell v. State, 225 Ga.App. 680, 681, 484 S.E.2d 751 (1997). The trial court allowed defense counsel to fully explore whether the witness had struck a deal with the prosecution in exchange for his testimony or whether he had any other bias that might affect his testimony.
4. Kenney asserts that the trial court erred in allowing Qadir's clothing to be entered into evidence because the State failed to prove chain of custody. We disagree, because "[u]nlike fungible items, distinct physical objects which are identified upon observation require no custodial proof for admission into evidence at trial." Pryor v. State, 231 Ga.App. 136, 137-138(5), 497 S.E.2d 805 (1998) (holding chain of custody not required for ski mask and hood).
5. Kenney argues that the trial court erred in sentencing him to serve 15 years. He asserts that OCGA § 17-10-6.1(c)(3), which provides that armed robbery convicts are not eligible for parole, is unconstitutional as applied to juveniles tried as adults. This challenge to the constitutionality of the statute is raised for the first time on appeal and, therefore, cannot be considered. Westmoreland v. State, 215 Ga.App. 21, 449 S.E.2d 640 (1994); Grice v. State, 199 Ga. App. 829, 406 S.E.2d 262 (1991).
Judgment affirmed.
JOHNSON, C.J., and SMITH, J., concur.
NOTES
[1]  Sirajuddin Qadir was convicted of four counts of armed robbery in a trial from which Joshua Kenney was severed. Those convictions were affirmed in Qadir v. State, 235 Ga.App. 884, 510 S.E.2d 362 (1998).
