In 2009, petitioner Charlton Green was convicted in the Superior Court of Cherokee County, Georgia, of failing to register as a sex offender as required by Georgia law. Green moved the Court for a new trial, claiming that his trial attorney had rendered ineffective assistance under Strickland v. Washington , 466 U.S. 668, 104 S.Ct. 2052, 80 L.Ed.2d 674 (1984), by failing to argue that the conviction giving rise to the obligation to register, a 1999 sodomy conviction, had been nullified by the United States Supreme Court's intervening decision in Lawrence v. Texas , 539 U.S. 558, 123 S.Ct. 2472, 156 L.Ed.2d 508 (2003). The Superior Court denied the motion for a new trial, and Green appealed. The Georgia Court of Appeals concluded that his attorney's failure to present the argument to the Superior Court caused Green no prejudice under Strickland , and affirmed his conviction.
In the proceedings below, the United States District Court for the Northern District of Georgia disagreed and, pursuant to 28 U.S.C. § 2254, issued a writ of habeas corpus setting aside Green's failure-to-register conviction on the ground that his sodomy conviction was invalid under Lawrence and that his attorney's failure *980to raise that point in the Superior Court resulted in Strickland prejudice.
We reverse. Green's claim that Lawrence voided his sodomy conviction was unexhausted and the District Court therefore erred by entertaining it. Further, the Court of Appeals, in light of Georgia state law, correctly found that Green suffered no Strickland prejudice.
I.
On June 1, 1997, Charlton Green allegedly performed a sexual act on a sixteen-year-old male in a hotel room while two others were present.1 Days later a Pickens County, Georgia, grand jury indicted Green in two counts, I and II, for committing sodomy, in violation of O.C.G.A. § 16-6-2 ; in three counts, III through V, for furnishing alcohol to a person under twenty-one years of age, in violation of O.C.G.A. § 3-3-23 ; and in five counts, VI through X, for contributing to the delinquency of a minor, in violation of O.C.G.A. § 16-12-1. On arraignment in the Pickens County Superior Court, Green pleaded not guilty to the charges.
At the time he allegedly committed the offenses charged in the ten-count indictment, Green was on a three-year term of probation for offenses committed in Georgia in 1995. On October 10, 1997, Green pleaded guilty to Counts I and VI through X of the indictment pursuant to a plea agreement.2 The Court accepted his guilty pleas and sentenced him as a "First Offender"-meaning that adjudication of guilt was withheld-to a three-year term of probation.3 As a condition of probation, the Court "banished" him from the Appalachian Judicial Circuit,4 transferred the supervision of his probation to the county of his subsequent residence, and warned him that if he violated the conditions of his probation, he "could suddenly be looking at 20 years" of confinement.
Within a year, Green violated those conditions. On January 6, 1999,5 the Superior Court revoked his probation, adjudged him guilty on Counts I and VI through X of his indictment, and sentenced him as follows: Count I, five years' probation with the first ten months to be served in custody; and Counts VI through X, twelve months' probation to be served concurrently with the Count I sentence.6 Once again, the Court banished Green from the Appalachian Judicial Circuit. As both a consequence of his Count I sodomy conviction and a condition of his probation, Green had to register as a sex offender under Georgia law, O.C.G.A. § 42-1-12.
In September 1999, Green moved the Pickens County Superior Court to terminate or modify his sentence on Count I in light of Powell v. State , in which the Georgia Supreme Court held that O.C.G.A. § 16-6-2 violated Georgia's Constitution "insofar as it criminalize[d] the performance *981of private, unforced, non-commercial acts of sexual intimacy between persons legally able to consent." 270 Ga. 327, 510 S.E.2d 18, 26 (1998). The Superior Court, with no explanation, found Powell inapplicable and denied the motion. Green did not appeal its decision.
On May 14, 2003, while serving the five-year term of probation imposed by the Pickens County Superior Court on January 6, 1999, Green was charged in Cherokee County with one count of criminal damage to property, in violation of O.C.G.A. § 16-7-23, and three counts of criminal trespass, in violation of O.C.G.A. § 16-7-21. He pleaded guilty to the charges and was placed on probation for a period of five years.7
In October 2004, while on probation, Green was indicted in Cherokee County on two counts of attempting to traffic methamphetamine, in violation of the Georgia Controlled Substances Act, O.C.G.A. § 16-13-30. After Green was taken into custody, he was indicted for failure to register as a sex offender, in violation of O.C.G.A. § 42-1-12. On January 25, 2005, Green appeared before the Cherokee County Superior Court and pleaded guilty to one of the drug-trafficking counts and to the failure-to-register charge. The Court sentenced him to prison for two years for the drug offense and to a concurrent one-year prison term for the failure-to-register offense.
In December 2008, Green was again indicted in Cherokee County for failure to register as a sex offender. He was charged this time as a recidivist. In May 2009, the Superior Court, following a bench trial in which Green was represented by retained counsel, found him guilty as charged and sentenced him to a thirty-year split sentence, with two years to be served in prison and the balance on probation.
Green retained new counsel and moved the Court for a new trial. He first contended that the State's evidence was insufficient because the 1999 sodomy conviction was invalid under Lawrence , 539 U.S. 558, 123 S.Ct. 2472, 156 L.Ed.2d 508, and Powell , 270 Ga. 327, 510 S.E.2d 18. That is, the State could not prove an element of the failure-to-register violation-a valid underlying conviction for a sexual offense. He then argued that his trial counsel rendered ineffective assistance under Strickland , 466 U.S. 668, 104 S.Ct. 2052, 80 L.Ed.2d 674, by not objecting to the failure-to-register charge because the duty to register was based on a constitutionally invalid sodomy conviction. Trial counsel should have challenged the validity of the conviction because, under Lawrence and Powell , it was based on constitutionally protected conduct.8
The State resisted the motion on the ground that the Cherokee County Superior Court lacked jurisdiction to entertain an attack on the validity of Green's sodomy conviction. It argued that the Pickens County Superior Court was the only court with jurisdiction to vacate the conviction. If that court set it aside, the State would dismiss the failure-to-register charge.
*982The Cherokee County Superior Court agreed with the State that the Pickens County Superior Court was the proper forum for mounting a collateral challenge to the validity of Green's sodomy conviction.9 Since Green had not petitioned that court for relief, the sodomy conviction was valid for purposes of the failure-to-register prosecution. But, despite its being the improper forum, the Court granted Green's attorney's request to present testimony depicting the sexual activity that, according to counsel, formed the basis of the conviction. The attorney called one witness, the man Green allegedly sodomized. He testified that two girls, one a friend, were present in the hotel room when the act took place.
At the close of the hearing, the Court reiterated that the Pickens County Superior Court was the appropriate forum for litigating Green's claim that his sodomy conviction was invalid. The Court accordingly denied Green's motion for a new trial and his claim that his trial attorney's performance was constitutionally deficient under Strickland. As for the testimony of the witness counsel had presented, the Court concluded that the sexual encounter was not private and thus not protected by the Powell and Lawrence holdings.
Green appealed his failure-to-register conviction and the denial of his motion for a new trial to the Georgia Court of Appeals. At the same time, he collaterally attacked his sodomy conviction by filing a "Motion to Pronounce a Valid Judgment" in the Pickens County Superior Court. The Court, citing Powell and Lawrence , granted the motion. The State appealed, and the Court of Appeals reversed on procedural grounds, holding that "because a motion to vacate a judgment of conviction is not an established procedure for challenging the validity of a judgment in a criminal case, Green was not authorized to seek relief from his criminal conviction pursuant to such a motion." State v. Green , 308 Ga.App. 33, 706 S.E.2d 720, 721 (2011) (footnote omitted). A petition for a writ of habeas corpus filed in the Pickens County Superior Court would provide Green with the means for attacking his conviction under Powell and Lawrence.
In the meantime, while the State's appeal of the Pickens County Superior Court's decision was still pending, the Court of Appeals affirmed Green's failure-to-register conviction and the denial of his motion for a new trial. Green v. State , 303 Ga.App. 210, 692 S.E.2d 784 (2010). The Court acknowledged that since Powell and Lawrence announced new rules of substantive criminal law, Green's sodomy conviction was subject to collateral attack in the Pickens County Superior Court, the court in which he had been convicted. Id. at 786. However, the Court said that it "cannot apply [ Powell and Lawrence ] in the instant case as it is not here on collateral review. This appeal is from a conviction for failure to register as a sexual offender, which is a proceeding separate from the defendant's [sodomy] offense." Id. Turning to the trial court's denial of Green's ineffective-assistance claim, which was before the Court *983for review, the Court pretermitted Strickland 's performance inquiry and found that trial counsel's failure to object to the prosecution of the failure-to-register offense on the basis of the Powell and Lawrence holdings caused Green no prejudice. Id. at 786-87. The Court based its finding on two grounds. First, trial counsel's objection would have been overruled on the ground that the Cherokee County Superior Court was an inappropriate forum for challenging the sodomy conviction. Second, and alternatively, because the conduct underlying the sodomy conviction was not private, it was not protected by Powell and Lawrence. As the trial court had found based on the victim's testimony, those decisions were inapplicable "because the [sexual] conduct was not 'private,' given the presence of other people in the room." Id. at 787.
II.
After the Court of Appeals affirmed his failure-to-register conviction, Green filed the habeas petition now before us. It presented the same ineffective-assistance claim the Court of Appeals had rejected.10 To obtain the writ, 28 U.S.C. § 2254, as amended by the Antiterrorism and Effective Death Penalty Act of 1996, Pub. L. No. 104-132, 110 Stat. 1214, required that Green demonstrate that the Court of Appeals' adjudication of his Strickland claim
(1) resulted in a decision that was contrary to, or involved an unreasonable application of, clearly established Federal law, as determined by the Supreme Court of the United States; or
(2) resulted in a decision that was based on an unreasonable determination of the facts in light of the evidence presented in the State court proceeding.
28 U.S.C. § 2254(d). Green did not contend that the Court of Appeals' adjudication rested on an unreasonable determination of facts. His burden was thus to prove that its decision "was contrary to, or involved an unreasonable application of," the Supreme Court's holdings in Strickland. This burden is "difficult to meet," as § 2254(d)"demands that state-court decisions be given the benefit of the doubt." Cullen v. Pinholster , 563 U.S. 170, 181, 131 S.Ct. 1388, 1398, 179 L.Ed.2d 557 (2011) (internal quotation marks omitted).
A.
The District Court referred Green's petition to a Magistrate Judge for a report and recommendation. At this point, the petition effectively morphed into two discrete § 2254 petitions. The first collaterally attacked Green's 1999 sodomy conviction as invalid under Lawrence. The second attacked his failure-to-register conviction on the ground that trial counsel was ineffective in not objecting to the failure-to-register prosecution on the basis of the allegedly invalid sodomy conviction.
The Magistrate Judge, in his Report and Recommendation, concluded that Green's petitions should be denied. He recommended the first petition be rejected on *984three grounds. First, Rule 2(e) of the Rules Governing Section 2254 Cases in the United States District Courts requires petitioners to file separate petitions when seeking relief from the judgments of more than one state court. Because Green was challenging his failure-to-register conviction, obtained in Cherokee County, he could not use the same petition to challenge his sodomy conviction, obtained in Pickens County.11 Second, § 2254 requires the petitioner to be in custody for the challenged offense, which Green no longer was for his sodomy conviction. Third, even assuming that Green was in custody since he was being detained pursuant to his failure-to-register conviction, he had not exhausted his claim that the sodomy conviction was invalid under Lawrence.12
Turning to Green's second petition, the Magistrate Judge concluded that Green had not shown that the Court of Appeals' adjudication of his ineffective-assistance claim was contrary to, or involved unreasonable application of, Strickland. As the Court of Appeals had held, Green failed to satisfy Strickland 's prejudice prong. Under Georgia law, the Cherokee County Superior Court lacked authority to entertain a collateral attack on his Pickens County sodomy conviction and thus was required to treat the conviction as constitutionally valid. Green effectively conceded as much.13
Green objected to the Report and Recommendation. Regarding the Magistrate Judge's disposition of his collateral attack on his sodomy conviction, Green contended that the Magistrate Judge erred in concluding that § 2254 relief was unavailable because he was no longer "in custody" pursuant to that conviction. The Magistrate Judge, he insisted, misinterpreted his habeas petition. He argued that his petition did not seek relief from his sodomy conviction. Rather, he was challenging his failure-to-register conviction on the ground that it was based on an invalid sodomy conviction. Had his trial attorney timely alerted the Cherokee County Superior Court to the invalidity of the conviction, the Court, bound by Powell and Lawrence , would have declared it a nullity and dismissed the failure-to-register charge.14
B.
The District Court sustained Green's objection to the Report and Recommendation and issued a writ of habeas corpus setting aside his failure-to-register conviction. It disagreed with the Magistrate Judge's reading of Green's petition as consisting of two independent § 2254 petitions, one collaterally attacking Green's sodomy conviction and the other his failure-to-register conviction. The Court concluded that Green's single petition challenged only the *985latter conviction-on the sole ground that his trial attorney was ineffective for failing to object to the sodomy conviction's use "to prove an element of the crime of failure to register as a sex offender."
From there, the District Court did not expressly address the Georgia Court of Appeals' holding that Georgia law prevented it from entertaining a collateral attack on Green's sodomy conviction in the context of the appeal of his failure-to-register conviction.15 Nor did the Court expressly consider whether Green had exhausted his claim that his sodomy conviction was invalid.16 Rather, invoking Lackawanna County District Attorney v. Coss , 532 U.S. 394, 121 S.Ct. 1567, 149 L.Ed.2d 608 (2001), the Court concluded that it could entertain Green's unexhausted challenge to his sodomy conviction in considering whether the Court of Appeals' rejection of his Strickland claim constituted a decision that was contrary to, or involved an unreasonable application of, Strickland. The Court acknowledged that, generally, Lackawanna barred the Court from doing so. See id. at 403-04, 121 S.Ct. at 1574. But it held that the general bar did not apply here due to a narrow exception in Lackawanna which allows § 2254 petitioners to "challenge an enhanced sentence on the basis that the prior conviction used to enhance the sentence was obtained where there was a failure to appoint counsel in violation of ... Gideon v. Wainwright. " Lackawanna , 532 U.S. at 404, 121 S.Ct. at 1574. The District Court reasoned that the alleged constitutional defect in Green's failure-to-register conviction-that it was premised on a prior sodomy conviction potentially invalid under Lawrence -was akin to the failure to appoint counsel for an indigent; both defects, it held, "ris[e] to the level of a jurisdictional defect." Cf. id. In sum, it was free under Lackawanna 's exception for Gideon violations to entertain the collateral attack on Green's sodomy conviction.
Having concluded that it could rule on the validity of the sodomy conviction, the District Court proceeded to determine the facts underpinning the conviction. In doing so, it effectively created the Pickens County Superior Court record of Green's sodomy conviction. It relied on the facts set forth in Green's 1997 indictment and those disclosed by the testimony the victim presented at the hearing on the motion for a new trial Green filed following his failure-to-register conviction, assuming that those were all of the facts presented to the Pickens County Superior Court when he pleaded guilty back in 1997. On these facts, the District Court held that Green's sexual conduct was consensual and private, and thus protected under Lawrence. Green should not have been required to register as a sex offender and therefore could not be held guilty of the instant offense. Thus, the Court concluded, had Green's counsel objected to the sodomy conviction's use to *986prove that offense, the trial court would have-or at least should have-reached the same conclusion. The District Court accordingly held that counsel was ineffective and that the Georgia Court of Appeals' decision to the contrary was based on "an unreasonable determination of the facts in light of the evidence presented" at the hearing on Green's motion for a new trial.17 See 28 U.S.C. § 2254(d)(2).
III.
The State appealed the District Court's decision, arguing that the Court lacked authority to entertain Green's challenge to the validity of his sodomy conviction, and that it mistakenly concluded that the Georgia Court of Appeals' Strickland decision was unreasonable. We agree.
A.
To start, Green had not exhausted his claim that his sodomy conviction was invalid under Lawrence.18 The Court of Appeals held, in State v. Green , 706 S.E.2d at 721, that the "Motion to Pronounce a Valid Judgment" Green filed in the Pickens County Superior Court was legally ineffective to challenge the conviction, and, in Green v. State , 692 S.E.2d at 786, that it lacked jurisdiction to consider the validity of the sodomy conviction in reviewing Green's failure-to-register conviction in the Cherokee County Superior Court. For purposes of habeas review, we must accept these pronouncements of Georgia law. See Estelle v. McGuire , 502 U.S. 62, 67-68, 112 S.Ct. 475, 479-80, 116 L.Ed.2d 385 (1991). Any challenge to Green's sodomy conviction was therefore unexhausted. The District Court consequently erred by addressing the validity of the sodomy conviction, albeit in the context of deciding whether the Court of Appeals' Strickland decision was based on an unreasonable determination of the facts.
Green contends, though obliquely, that the District Court nonetheless had the authority under Lackawanna to entertain his Lawrence challenge to his sodomy conviction. Lackawanna generally bars habeas petitioners from using their challenge of a current conviction to also attack the validity of an earlier conviction for which they are no longer in custody.19 This bar is lifted only in cases where the earlier conviction was obtained in violation of Gideon.20 Here, there was no alleged Gideon *987violation. And Lackawanna 's exception for Gideon violations does not, as the District Court believed, apply to Green's Lawrence claim.21
B.
In addition to entertaining an unexhausted claim, the District Court improperly found that the Court of Appeals' Strickland decision was based on an unreasonable determination of the facts.22 The Court granted Green's petition and set aside his failure-to-register conviction after concluding that the Court of Appeals should have found prejudice under Strickland. See 28 U.S.C. § 2254(d). The Court of Appeals, however, properly determined that Lawrence applies retroactively only to cases on collateral review. Under Georgia law, Green's sodomy conviction was not before it on collateral review. Rather, Green was directly appealing his failure-to-register conviction, a separate offense. Therefore, neither the Court of Appeals nor the trial court could have entertained a challenge to Green's sodomy conviction in light of Lawrence ; no evidence of the conviction's invalidity could come in. For Green to make that challenge, he would have had to properly file a separate habeas petition in Pickens County, which he did not do. Green thus could not possibly have suffered Strickland prejudice-objecting to the sodomy conviction's use as the basis for the failure-to-register prosecution would have been futile.
*988To reach the holding it did, the District Court implicitly held that the Court of Appeals erred by not treating Green's direct appeal also as a collateral attack on his sodomy conviction. That would have been the only way for the Court of Appeals to allow in evidence of the invalidity of Green's sodomy conviction under Lawrence , and for it to find prejudicial Green's trial counsel's failure to challenge the sodomy conviction under Lawrence. But under Georgia law, Green's failure-to-register appeal could not also have served as a forum for a collateral attack on the sodomy conviction. Indeed, the Court of Appeals later confirmed this when ruling on the Motion to Pronounce a Valid Judgment that Green filed in Pickens County Superior Court. There, the Court of Appeals made clear that filing a separate writ of habeas corpus in Pickens County was the only way Green could attack his sodomy conviction.
The District Court therefore rendered a decision based on what it considered to be the Court of Appeals' erroneous interpretation of Georgia law-that Georgia law precluded it from entertaining Green's collateral attack on his sodomy conviction. The District Court erred. On habeas review, federal courts may not second guess state courts on questions of state law. Green does not challenge that proposition here. Accepting the Court of Appeals' interpretation of Georgia law, it was thus correct in holding that Green did not suffer Strickland prejudice. The Superior Court, applying Georgia law, would have overruled Green's attorney's timely objection to the failure-to-register prosecution on the theory that it was based on a sodomy conviction invalid under Lawrence.
IV.
We reverse the District Court's judgment for the foregoing reasons and deny Green's petition for a writ of habeas corpus.
REVERSED.