We review Mr. Carter's ex post facto claim de novo. See United States v. Mashek, 406 F.3d 1012, 1016 (8th Cir. 2005). The ex post facto clause is violated when a law defining a crime or increasing punishment for a crime, see Collins v. Youngblood, 497 U.S. 37, 43, 110 S. Ct. 2715, 111 L. Ed. 2d 30 (1990), is applied to events that occurred before its enactment, to the "disadvantage" of the offender, Weaver v. Graham, 450 U.S. 24, 29, 101 S. Ct. 960, 67 L. Ed. 2d 17 (1981). In Miller v. Florida, 482 U.S. 423, 435-36, 107 S. Ct. 2446, 96 L. Ed. 2d 351 (1987), the Supreme Court held that retroactive application of state sentencing guidelines that subjected offenders to longer sentences than they would have received at the time the crime was committed, violated the ex post facto clause applicable to the states, see U.S. Const., art. I, § 10, c1. 1. And we have held that the ex post facto clause applicable to Congress is similarly violated by retroactive application of a more onerous federal sentencing guideline. United States v. Bell, 991 F.2d 1445, 1448 (8th Cir.1993); see U.S. Const. art. I, § 9, cl. 3.

Initially, we note that since the Supreme Court decided United States v. Booker, 543 U.S. 220, 125 S. Ct. 738, 160 L.Ed.2d 621(2005), at least one of our sister circuits has held that the ex post facto clause does not apply to the now-advisory guidelines. See United States v. Demaree, 459 F.3d 791, 794 (7th Cir.2006), petition for cert. filed, No. 06-8377 (U.S. Dec. 11, 2006); see also United States v. Barton, 455 F.3d 649, 655 n. 4 (6th Cir.2006). But in a case decided after Booker, we "recognize[d] that `retrospective application of the Guidelines implicates the ex post facto clause,'" though we took into account post-offense amendments to the guidelines when determining the overall reasonableness of the defendant's sentence. United States v. Larrabee, 436 F.3d 890, 894 (8th Cir.2006) (quoting Bell, 991 F.2d at 1448). Given our decision in Larrabee, we will proceed to address Mr. Carter's ex post facto claim.

The guidelines themselves refer to the ex post facto clause: under U.S.S.G. § 1B1.11(a) and (b)(1), courts are directed to apply the version of the guidelines in effect on the date of sentencing unless to do so would violate the ex post facto clause, in which case the guidelines in effect on the date of the crime should be used. The so called one-book rule requires that the "Guidelines Manual in effect on a particular date be applied in its entirety." U.S.S.G. § 1B1.11(b)(2). And the guidelines specify that "[i]f the defendant is convicted of two offenses, the first committed before, and the second after, a revised edition of the Guidelines Manual became effective, the revised edition of the Guidelines Manual is to be applied to both offenses." U.S.S.G. § 1B1.11(b)(3).

In this appeal, Mr. Carter argues that in his case, by applying the one-book rule, see U.S.S.G. § 1B1.11(b)(2), and using the date when the last crime was committed to determine which edition of the guidelines to apply, cf. U.S.S.G. § 1B1.11(b)(3), the district court violated the ex post facto clause. According to the defendant, the court violated the clause by sentencing him under a version of the guidelines that included U.S.S.G. § 4B1.5(b)(1), an enhancement for repeat sex-offenders that went into effect on November 1, 2001, see U.S.S.G. app. C, amend. 615, thereby increasing his offense level and guideline sentencing range "for the three most serious pre-November, 2001 grouped Counts." Mr. Carter argues that even if, as we held in Carter I, the evidence supported a finding that one of his crimes (Count II) occurred after November 1, 2001, he was unconstitutionally disadvantaged by the application of § 4B1.5(b)(1) to the three more serious crimes that occurred before that date and could not be grouped with Count II. Cf. United States v. Ortland, 109 F.3d 539, 547 (9th Cir.1997).

The government maintains that Mr. Carter's claim is precluded by the law-of the-case doctrine because of our ruling against him on an ex post facto claim in Carter I, 410 F.3d at 1026-27. In general, "the law-of-the-case doctrine posits that when a court decides upon a rule of law, that decision should continue to govern the same issues in subsequent stages in the same case." Arizona v. California, 460 U.S. 605, 618, 103 S. Ct. 1382, 75 L. Ed. 2d 318 (1983); see also United States v. Bartsh, 69 F.3d 864, 866 (8th Cir.1995).

At the first sentencing hearing, the district court carefully followed the provisions of § 1B1.11. The court first rejected the 2003 guidelines manual in effect at that time based on ex post facto concerns, see § 1B1.1(a), (b)(1), explaining that the then-current manual might produce a higher sentence because it included a new prohibition on downward departures for sexual crimes and eliminated a multiple-victim requirement for an enhancement under § 4B1.5(b). Then the court referred to the one-book rule, see § 1B1.11(b)(2), and the need to use the guidelines manual in effect when the last crime was committed, see § 1B1.11(b)(3). Following these provisions, the district court applied the manual that "went into effect on November 1, 2001, in between the defendant's offenses of conviction" (though it mistakenly referred to it as the 2002, rather than the 2001, manual). The court found generally that "at least one" of Mr. Carter's crimes occurred after § 4B1.5(b)(1) went into effect (November 1, 2001), and it also relied on the indictment to determine that Count VII occurred after that date.

In his first appeal, Mr. Carter maintained in his brief that the district court erred by enhancing his sentence under § 4B1.5(b)(1) "where the prosecution's evidence failed to prove that any of the charged offenses" occurred after that enhancement went into effect. He asserted that the "trial testimony did not prove an offense" after that date and also contended that the district court should have relied on the evidence, rather than the indictment, to determine when Count VII occurred. Significantly, Mr. Carter did not challenge the constitutionality of § 1B1.11 (b)(2) or § 1B1.11 (b)(3) or the district court's decision to calculate his sentence by applying only "one book" of sentencing guidelines, i.e., the one in effect when his last crime was committed. And though he now contends that the court should not have relied on the date of a lesser crime to increase his sentence for earlier more serious crimes that could not be grouped with the later crime, in his first appeal he mentioned neither the relative seriousness of the crimes nor their groupability. We rejected Mr. Carter's previous ex post facto claim in Carter I, 410 F.3d at 1027, because evidence regarding Count II supported the district court's finding that at least one of the crimes occurred after November 1, 2001. We noted that the victim in Count II, who was a minor at the time of the crime, testified that Mr. Carter had sexual contact with her in December, 2001, and, when pressed on cross-examination, estimated the date as "around November 2, 2001." After remand, the district judge reiterated that at least one of Mr. Carter's crimes occurred after § 4B1.5 went into effect, basing his finding on the "trial testimony ... that the contact happened around November 2, 2001."

We agree with Mr. Carter's contention in his reply brief that the law-of-the case doctrine does not apply because we "did not issue a legal ruling" in Carter I addressing whether the ex post facto clause "prohibits using a single less serious, later offense to justify the retroactive application" of a guideline to increase the sentencing range "for earlier ungrouped more serious offenses." But we did not address the issue because Mr. Carter did not raise it, and we conclude that the issue has been forfeited.

Mr. Carter asserts that he did not raise the argument earlier because at the first sentencing the district court specifically referred only to Count VII and did not mention Count II when deciding to apply the 2001 guidelines. We believe, however, that the argument is not dependent on the court mentioning Count II, but is a challenge to the district court's determination that the 2001 guidelines applied because at least one crime occurred after November 1, 2001. And Mr. Carter's rationale for not making his current ex post facto argument is particularly unpersuasive because Counts II and VII are virtually identical: they both charge Mr. Carter with abusive sexual contact with a minor in violation of 18 U.S.C. § 1153, on dates after November 1, 2001, and neither crime was groupable with the earlier more serious offenses, see U.S.S.G. § 3D1.2 cmt. (n. 3, 4). Therefore we believe that Mr. Carter's argument would be equally available regardless of whether the district court referred to Count II or Count VII when determining which version of the guidelines to apply.

Not until this appeal did Mr. Carter argue that the ex post facto clause precluded the application of the 2001 guidelines even if one of his crimes took place after November 1, 2001. This is not simply a case where the defendant appeals an issue that he or she did not present to the district court. Cf. United States v. Rees, 447 F.3d 1128, 1130 (8th Cir.2006). Here Mr. Carter did not raise this issue at his first sentencing, in his appeal from that sentence, or at resentencing. We do not permit piecemeal appeals, and we choose not to afford Mr. Carter an opportunity (unavailable to other defendants) to raise a new issue at this late date merely because his case was remanded on other grounds. See United States v. Palmer, 297 F.3d 760, 767 (8th Cir.2002); United States v. Montoya, 979 F.2d 136, 138 (8th Cir.1992); United States v. Fiallo-Jacome, 874 F.2d 1479, 1481-83 (11th Cir.1989). We conclude that Mr. Carter has forfeited his current ex post facto claim, and thus we decline to address it on the merits.

Mr. Carter next argues that the district court failed to make adequate findings to support an obstruction-of-justice enhancement based on perjury, see U.S.S.G. § 3C1.1. Since Mr. Carter objected to the enhancement, the court was required to "review the evidence and make independent findings necessary to establish ... obstruction of justice." United States v. Dunnigan, 507 U.S. 87, 95, 113 S. Ct. 1111, 122 L. Ed. 2d 445 (1993). Although it is preferable for the court "to address each element of the alleged perjury in a separate and clear finding," a finding "that encompasses all of the factual predicates for a finding of perjury" is sufficient. Id.

We conclude that there is no merit to Mr. Carter's contention that the district court did not make adequate findings here. The court stated during the sentencing hearing that it found "that Mr. Carter ... testified falsely as to all these different sexual assaults, all of which was testimony on material matters." The judge added that he was "making that finding based upon what I saw and heard at trial." At another point, the judge stated that the evidence in Mr. Carter's case was "as strong as [he'd] seen in any case" during nine years on the bench and that he would have found Mr. Carter guilty in a bench trial.

In Dunnigan, the Court concluded that the district court's findings that "the defendant was untruthful at trial with respect to material matters" and that the defendant's "failure to give truthful testimony on material matters ... were [sic] designed to substantially affect the outcome of the case" were sufficient to support the enhancement. Id. (emphasis in Dunnigan). The district court undoubtedly made independent findings in Mr. Carter's case, and we believe that the court's statements are substantially similar to those that we have previously concluded are sufficient. See, e.g., United States v. Kessler, 321 F.3d 699, 703 (8th Cir.2003).

Finally, we note that Mr. Carter mistakenly relied in his brief on United States v. Cabbell, 35 F.3d 1255, 1261 (8th Cir.1994) (quoting United States v. Willis, 940 F.2d 1136, 1140 (8th Cir.1991), cert. denied, 507 U.S. 971, 113 S. Ct. 1411, 122 L. Ed. 2d 782 (1993)), for the proposition that an obstruction-of-justice enhancement should not be imposed based upon a defendant's testimony "`if a reasonable trier of fact could find the testimony true.'" This statement, first made in Willis, 940 F.2d at 1140, was based directly on an application note to U.S.S.G. § 3C1.1 (n.1) (1990) that required a sentencing court to evaluate any suspect testimony or statements in the light most favorable to the defendant when determining whether he or she had committed penury. But the Sentencing Commission amended that application note in 1997 "so that it no longer suggests the use of a heightened standard of proof," U.S.S.G. app. C, amend. 566, and thus there was no longer a basis for our statement in Willis. Rather than viewing the evidence favorably to the defendant or to the verdict, the district court now makes independent findings based on a preponderance of the evidence, and we review those findings for clear error only. See United States v. Guel-Contreras, 468 F.3d 517, 522 (8th Cir.2006). Understandably, Mr. Carter does not contend here that the findings of the district court are clearly erroneous.

For all of the above reasons, we affirm the judgment of the district court.