The issue in this case is whether the ex post facto clause is violated when a statutory amendment that increases a penalty to be imposed upon the revocation of supervised release is applied in a case in which the underlying offense was committed before the amendment was adopted but the conduct that led to revocation of supervised release occurred afterwards. We conclude that applying the amendment under such circumstances violates the ex post facto clause.
I.
Stuart Jeffrey Paskow conspired to receive the proceeds of a bank robbery and received of the proceeds of a bank robbery, in violation of 18 U.S.C. §§ 371, 2113(c), in April and May of 1988. He pled guilty and was sen *876 tenced in August, 1990, to eight months’ imprisonment and three years of supervised release.
On December 31, 1988, several months after Paskow committed that underlying offense, an amendment to the supervised release statute, 18 U.S.C. § 3583, became effective. Anti-Drug Abuse Act of 1988,102 Stat. 4181, 4464, Pub.L. 100-690 § 7303(b). The amendment provides:
If the defendant is found by the court to be in the possession of a controlled substance, the court shall terminate the term of supervised release and require the defendant to serve in prison not less than one-third of the term of supervised release.
18 U.S.C. § 3583(g). Before the amendment was enacted, violation of supervised release for possession of a controlled substance carried no mandatory minimum penalty. Indeed, before the amendment, the only restriction on the court’s discretion was a requirement that no sentence could exceed two years (if the underlying offense was a Class C or D felony) or three years (if the underlying offense was a Class B felony). 18 U.S.C. § 3583(e). Thus, before the addition of the amendment, the statute imposed a ceiling on a court’s discretion, but set no floor. The effect of the amendment was to set a floor: one-third of the term of supervised release. Practically speaking, following the amendment, Paskow was subject to a mandatory minimum one-year sentence for violating supervised release. Prior to the amendment, he could have received no sentence at all.
Paskow began the supervised release portion of his sentence in December, 1990. The terms of his release required that he submit to random drug tests. In August, 1992, after random testing revealed that he had used marijuana and cocaine, his supervised release was revoked and he was sentenced to twelve months in prison, one-third of his term of supervised release, the mandatory minimum under the amendment. 18 U.S.C. § 3583(g). 1
At his revocation hearing, Paskow objected to his sentence on the ground that the amendment to the supervised release statute, as applied, violated the ex post facto clause. The district court held that, because the behavior for which his supervised release was revoked took place after the amendment became effective, the ex post facto prohibition was not violated. [RT 14-15]. Paskow now appeals. While the district court’s ruling has great appeal intuitively, a close analysis of Supreme Court and other precedent persuades us that we are required to reverse.
II.
Article I of the Constitution provides that neither Congress nor any state shall pass any ex post facto law. U.S. Const, art. I, § 9, cl. 3, art. I, § 10, cl. I. 2 An ex post facto law is not simply one that makes criminal an act that was lawful at the time it was committed, or a law that increases a sentence following the commission of the act for which punishment is imposed. The ex post facto provision applies to a wide range of changes affecting trial procedures and the mechanics of punishment.
The Supreme Court first analyzed the Constitution’s ex post facto clause in
Calder v. Bull,
I will state what laws I consider ex post facto laws, within the words and the intent of the prohibition. 1st. Every law that makes an action done before the passing of the law, and which was innocent when done, criminal; and punishes such action. 2d. Every law that aggravates a crime, or makes it greater than it was, when committed. 3d. Every law that changes the punishment, and inflicts a greater punishment, than the law annexed to the crime, *877 when committed. 4th. Every law that alters the legal rules of evidence, and receives less, or different testimony, than the law required at the time of the commission of the offence, in order to convict the offender.
Id.
at 390. Justice Chase’s formulation remains the core of the ex post facto prohibition.
Miller v. Florida,
Since
Colder,
a two-pronged test has been developed to determine whether the application of a penal law violates the ex post facto clause. “[Fjirst, the law ‘must be retrospective, that is, it must apply to events occurring before its enactment’; and second, ‘it must disadvantage the offender affected by it.’ ”
Miller v. Florida,
We now consider, first, whether Paskow was disadvantaged by the application of the amended statute, and, next, whether the statute is retrospective.
A.
The government concedes that the amended statute disadvantages Paskow. Indeed, any argument to the contrary would be foreclosed by
Lindsey v. Washington,
Here, before the supervised release statute was amended, Paskow was eligible to receive a sentence of less than one-third the term of his supervised release. 18 U.S.C. § 3583(e). After the amendment, the district court was no longer free to impose such a sentence. It is the difference between a court’s discretion to sentence a defendant to a particular term — or to one substantially shorter — and the absolute requirement that the defendant be sentenced to at least that term, that implicates the first prong of the ex post facto prohibition. We conclude that the application of the amended statute to Paskow disadvantaged him.
B.
We now consider the more difficult question whether the amended statute is retrospective as applied to Paskow. Following several decades of consistent case law, we conclude that it is.
1.
We find virtually dispositive the strong line of cases that decides this precise issue in connection with revocation of parole (as opposed to the revocation of supervised release at issue here). These cases hold that the ex post facto clause is violated when a parole violator is punished in a way that adversely affects his ultimate release date *878 under a statute that was adopted after the violator committed the underlying offense but before he violated the terms of his parole. For the purposes of an ex post facto analysis, there is absolutely no difference between parole and supervised release. The considerations that underlie each are identical.
The line of cases on which we rely involve parole because, until 1987, federal prisoners were subject to parole rather than to supervised release, see 18 U.S.C. § 3551 et seq. (setting forth the provisions of the Sentencing Reform Act of 1984), and because the states, by and large, still employ the parole system. 4 In these cases, the date of eligibility for parole is tantamount to a presumptive release date. The same is true of a date of eligibility for supervised release. To substitute “supervised release” for “parole” in no way changes the ex post facto analysis. In both cases, the question is at what time the prisoner is to be released from prison. A delay in that date constitutes the same punishment whether it is imposed following a parole violation or a violation of supervised release. Thus, whether the punishment is imposed in connection with the former violation or the latter is irrelevant for ex post facto purposes. If, as is the case, it is an ex post facto violation to impose more severe punishment for a parole violation when the punishment is based on conduct that occurs after the statutory amendment that authorizes the more severe punishment (because the amendment was not in effect at the time the underlying offense was committed), the same is necessarily true in the case of'the imposition of a more severe punishment for a violation of supervised release in like circumstances.
2.
It is clear that, in the case of parole revocation, it is unconstitutional to apply a statute that alters, to the defendant’s disadvantage, the terms under which eligibility for re-parole is calculated, if that statute was enacted after the date of the underlying offense — even though the act upon which revocation is based occurred after the enactment of the statute. The Supreme Court’s affir-mance of the three-judge panel decision in
Greenfield v. Scafati
Although the Supreme Court affirmed
Greenfield
in a memorandum opinion,
In
Greenfield,
a defendant who was incarcerated following revocation of his parole challenged a statute that prohibited any state parole violator from receiving good-conduct credits during his first six months in custody following revocation.
Circuit courts that have considered the ex post facto issue have, without exception, followed
Greenfield,
holding that the ex post facto clause is violated when a defendant’s eligibility for release is adversely affected under a statute that was not in effect at the time of the defendant’s underlying crime but was adopted before the defendant committed the act for which his parole was revoked.
5
Without exception, the circuit courts that have considered the ex post facto issue have looked to the date of the defendant’s original offense, not to the date of the conduct that led to the punishment for the parole violation. Without exception, they have based their holdings on the axiom that, as the Second Circuit phrased it, “parole eligibility is considered an integral part of any sentence.”
Shephard v. Taylor,
In
Beebe v. Phelps, supra,
a case factually identical to
Greenfield,
the Fifth Circuit concluded that the statute at issue, which forfeited good-time credits upon revocation of parole, violated the prohibition on ex post facto laws because it constituted “a sanction that extends the time remaining on petitioner’s
original
sentence” rather than a punishment for “the second offense” (the parole violation).
Similarly, the Fourth Circuit, considering a statute that made ineligible for parole any prisoner serving a life sentence who escaped from custody, held that the critical date for ex post facto purposes is not the date of the escape but rather the date of the offense for which the prisoner was originally sentenced. The court stated, “[S]tatutes enacted or amended after a prisoner was sentenced cannot be applied to alter the conditions of or revoke his or her preexisting parole eligibility-notwithstanding that the conduct purportedly triggering application of the statute occurred after its enactment.”
Fender v. Thompson,
The case law is absolutely clear. Greenfield and its progeny stand for the principle that the date of a prisoner’s eligibility for release on parole 7 is a component of a defendant’s original sentence. Greenfield also compels the conclusion that no adverse action can be taken at a parole revocation hearing that could not have been taken at such a hearing on the day the defendant committed the underlying crime. Finally, it requires us to conclude that the parole revocation must apply no more disadvantageous rules and standards than were in effect at that time. Here, as discussed above, there is no dispute that the amendment to the statute was disadvantageous to Paskow and subjected him to harsher treatment with respect to his release date than did the statute as it existed at the time he committed the underlying offense.
The government makes two arguments in opposition to the application of the Greenfield principle here. It contends that, because Paskow violated the terms of his supervised release after the effective date of the amended statute, he was on notice of the changed penalty for his conduct, and that the amended statute does not increase the penalty for a prior crime, but rather enhances the penalty for the revocation behavior.
These are the identical arguments that were made and rejected in the
Greenfield
line of cases.
See Fender v. Thompson,
3.
We have previously explained generally why supervised release is no different from parole for purposes of the Greenfield line of cases. Nevertheless, some further discussion may be helpful. The government, unfortunately, offers no rational basis for distinguishing the two. Nor can we conceive of *881 any reason at all why one rule should apply in supervised release cases while the opposite rule applies in parole revocation cases.
Supervised release and parole are virtually identical systems. Under each, a defendant serves a portion of a sentence in prison and a portion under supervision outside prison walls. If a defendant violates the terms of his release, he may be incarcerated once more under the terms of his original sentence. More specifically, a defendant’s original sentence determines the length of the term of parole (indirectly) or supervised release (directly). It is also the original sentence that establishes how long the defendant may be required to serve following revocation in the case of both parole and supervised release violations. 9 Finally, it is the original sentence that is executed when the defendant is returned to prison after a violation of the terms of both parole and supervised release.
Revocation of parole is not a punishment for a new offense, although the conduct on which revocation is based may be punished separately. For revocation purposes, the conduct simply triggers the execution of the conditions of the original sentence. Those conditions may not be made more severe, nor may the defendant’s term of rein-carceration after his violation be made more onerous, by any act adopted after he was sentenced. In this respect, there is no conceivable basis for distinguishing between parole and supervised release.
Two courts have specifically considered whether the parole cases apply in the context of supervised release. Both have held that they do, and that the ex post facto clause is violated when the amendment is applied to a defendant who committed his underlying offense before the statute was amended.
United States v. Parriett,
Flora was decided after the government submitted its brief in this case. The government’s only comment on Parriett is to note that the court seemed reluctant to reach its conclusion. The Parriett court stated that the law is absolutely clear in parole cases and that there is simply no way to distinguish supervised release from parole for ex post facto purposes. It found the weight of precedent inescapable. So do we. 10
*882 It is not only the cases that have considered supervised release and have found no distinction between it and parole, for ex post facto purposes, that compel our conclusion. Our result is also dictated by the text of the supervised release statute and the sentencing guidelines concerning supervised release.
As noted above, the case law makes clear that a defendant’s eligibility for release is “an integral part of any sentence.”
Shephard v. Taylor,
In sum, the case law and the language of the statute and guidelines cause us to conclude that there is no difference for ex post facto purposes between parole and supervised release. Each is a component of the defendant’s sentence. No conditions affecting either may be changed to his detriment after he commits the underlying crime. 12
*883 Summary
To summarize our analysis, it is beyond dispute that the ex post facto clause is violated when a parole violator is punished in a way that adversely affects his ultimate release date and the law that authorizes the punishment was adopted after the violator committed the underlying offensé, but before he violated the terms of his parole. The courts have spoken uniformly, and the government’s arguments to the contrary simply repeat contentions that have been rejected over the past twenty-five years.
The issue here is whether the same rule applies to supervised release. Our answer to that question is yes. As the Fourth Circuit stated, there is “no persuasive reason to distinguish between the standards of parole eligibility ... and the conditions for revocation of supervised release.”
United States v. Parriett,
One of the primary reasons for the application of the ex post facto clause is that conditions that affect a defendant’s eligibility for parole are part of his original sentence. So, too, are the conditions that affect the revocation of his supervised release. The language of both the supervised release statute and the sentencing guidelines make this clear. In fact, in formulating the guidelines, the Sentencing Commission expressly rejected the suggestion that a defendant’s behavior in violating the terms of his supervised release should be treated as a new substantive offense.
We believe that the guidelines, the statute, and, especially, the case law, compel our holding. We are bound by an unbroken and consistent line of cases that stretches back over a quarter of a century, including a case affirmed by the Supreme Court, one that the Court itself has declared to be controlling precedent.
In sum, a term of supervised re- ' lease, 18 U.S.C. § 3588, is “simply part of the whole matrix of punishment which arises out of a defendant’s original crimes.”
United States v. Flora,
VACATED AND REMANDED.
Notes
. Paskow was actually sentenced to a term of fifteen months and 27 days. The additional three months and 27 days were improperly imposed. We resolved the discrepancy between the twelvemonth sentence the judge intended to impose and the sentence actually imposed in an unpublished order. United States v. Paskow, No. 92-50616 (9th Cir. filed Sept. 9, 1993).
. “ 'So much importance did the [cjonvention attach to [the
ex post facto
prohibition], that it is found twice in the Constitution.' "
Weaver v. Graham,
. In addition, the provision in question must be a "law.”
See Miller v. Florida,
. Even before the effective date of the Sentencing Reform Act, some offenses required the imposition of a term of supervised release rather than special parole.
See, e.g.,
21 U.S.C. § 841(b)(1)(C) (requiring supervised release in addition to imprisonment for specified narcotics offenses). It was pursuant to this statute that the defendant in
United States v. Bermudez
was sentenced.
United States v. Bermudez,
. At first glance,
Warren v. United States Parole Comm’n,
We also note that in many instances courts have not reached the retrospectivity prong of the ex post facto analysis, finding instead that the new restrictions are not more onerous than the old,
see, e.g., Conner v. Estelle,
. The Fender court noted that the conduct that serves as the basis for parole revocation — the second offense — may be tried and punished separately as an independent crime and that, for that purpose, any statute adopted prior to the second offense may be applied. It distinguished punishment for the second offense itself from an increase in punishment for the original offense. Id. at 306-07. See also infra note 10.
. As noted above, the date of eligibility for parole is, in these cases, tantamount to a presumptive release date.
. We agree that an enhancement statute may escape the strictures of the ex post facto clause if it imposes a “stiffened penalty for the
latest
crime, considered to be an aggravated offense” because the defendant has committed prior crimes.
Gryger v. Burke,
We note that, in
Chatman v. Marquez,
. The sentence imposed at the time of revocation may not, of course, be more disadvantageous to the defendant than it could have been had it been imposed on the date of the crime.
. We note that one case, at first glance, may appear to contain contrary language.
United States v. Bermudez,
Bermudez did not involve an ex post facto issue. To the contrary-the appellant argued, and the court agreed, that she was entitled to the lighter sentence applicable under the guidelines rather than being punished by the more severe sentence applicable under the pre-guidelines law according to which she had originally been sentenced. See supra note 4 (explaining that some offenses were punishable by a term of supervised release rather than parole even before the effective date of the Sentencing Reform Act of 1984). The ex post facto clause is in no way implicated when a defendant's sentence is less severe under the new law than under the old. See supra Part II. A. Bermudez is not an ex post facto case. Nothing in Bermudez suggests any view of whether revocation of supervised release is an offense separate from the underlying offense for ex post facto purposes. Nor could the court have suggested any view, given the context in which the issue arose. In short, Bennudez does not purport to speak with respect to any ex post facto issue. Nor do any of the cases it cites. We consider our decision perfectly consistent with Bermudez and those cases.
. Instead, the Commission decided that "at revocation the court should sanction primarily the defendant’s breach of trust.” Id.
. United States v. Schram, 9 F.3d 741 (9th Cir.1993), is not to the contrary. There, we considered a policy statement, United States Sentencing Commission, Guidelines Manual, § 7B1.3(f), p.s. ("§ 7B1.3(f)”), that states that "any term of imprisonment imposed upon the revocation of ... supervised release shall be ordered to be served consecutively to any sentence that the defendant is serving, whether or not the sentence of imprisonment being served resulted from the conduct that is the basis of ... supervised release.” Id. We concluded that § 7B1.3(f) may be applied to a defendant who committed his underlying crime before the policy statement was adopted and who committed the substantive offense that led to the revocation of his supervised release after the policy statement's effective date. Our holding rested on the acknowledgment that the policy statement implicates the relationship between the penalty for violation of supervised release and the penalty for a new or different offense committed while the defendant is on supervised release. We upheld a rule that a prison term for the violation of supervised release must be served after the completion of any term being served for the new offense. By contrast, 18 *883 U.S.C. § 3583(g), the amendment to the supervised release statute at issue here, implicates the relationship between the penalty for violation of supervised release and the penalty for the underlying crime. Our holding-that, under 18 U.S.C. § 3583(g), the punishment for a violation of supervised release is a component of the punishment for the underlying crime and cannot be increased retroactively-is perfectly consistent with Schram.
