delivered the Opinion of the Court.
This is an appeal of a denial of a petition for a writ of habeas corpus. The petitioner, Bret A. Aue, brought this action in Chaffee County District Court, asking the court to order his release from the custody of the Colorado Department of Corrections (the Department). Aue argued that under the applicable parole provisions he was entitled to mandatory release on parole on April 9, 1989. The trial court dismissed his petition without a hearing, finding that he had stated no grounds entitling him to ha-beas corpus relief. We affirm.
I.
On July 21, 1986 Aue pled guilty to aggravated incest, section 18-6-302, 8B C.R.S. (1986), and sexual assault on a child, section 18-3-405, 8B C.R.S. (1986). The court sentenced Aue to seven years imprisonment on each count, to be served concurrently, and credited Aue with 187 days for *438 presentence confinement. 1 The Department projected Aue's parole release date as April 9, 1989. On January 18, 1989, however, the Colorado State Board of Parole (Parole Board) considered and denied his application for parole, deferring further consideration to January 1990. On March 15, 1989, Aue filed a petition for a writ of habeas corpus seeking release from the custody of the Department. The district court denied his petition and Aue took this appeal.
Aue argues that he was subject to “mandatory parole” on April 9, 1989, under section 18 — 1—105(l)(b)(I), 8B C.R.S. (1986), section 16-11-310, 8A C.R.S. (1986), section 17-22.5-301, 8A C.R.S. (1986), and section 17-22.5-302, 8A C.R.S. (1986). Aue argues that section 17-2-201(5)(a), 8A C.R.S. (1986), which provides for certain exceptions from the mandatory parole scheme, does not authorize discretionary parole for his convictions of aggravated incest and sexual assault on a child. However, we rejected this same argument in
Thiret v. Kautzky,
II.
Aue further argues that even if this court construes the parole provisions as authorizing discretionary parole of persons sentenced for a sex offense, applying this interpretation of the statutes to him would be the equivalent of ex post facto legislation forbidden by Article I, Section 10 of file United States Constitution, and Article II, Section 11 of the Colorado Constitution, and would violate his right to due process. He also asserts that such interpretation violates his right of equal protection because other similarly situated prisoners were released under the Parole Board’s prior interpretation of these statutes. He claims that, at the time of his guilty plea, the long-standing agency interpretation, contrary to the present position of the Parole Board, led him to believe that he would be eligible for mandatory parole. 2 Before considering whether our decision in Thiret can be applied to Aue, a brief review of the principles governing “judicial ex post fac-to” is in order.
An
ex post facto
law is one “that makes an action done before the passing of the law, and which was innocent when done, criminal; and punishes such action,” or “that aggravates a crime, or makes it greater than it was, when committed.”
Calder v. Bull,
Judicial decisions normally are applied retrospectively, that is, “they apply to conduct that occurred before the decision was rendered.”
E.E.O.C. v. Vucitech,
Several lower federal court decisions have considered arguments like those raised by Aue in circumstances analogous to the facts of the present case. In
Lerner v. Gill,
Lerner argued in federal court that the changed interpretation of the effect of the Rhode Island parole provisions could not be applied retrospectively to him without offending ex post facto and due process principles. The court of appeals rejected Lerner’s arguments holding:
While [the attorney general] construed the 1970 amendment in [the manner suggested by Lerner], his successor did not, and most significantly, the Supreme Court of Rhode Island has not. See R.I. Const.Amend. XII, § 1 (Supreme Court has final revisory jurisdiction over all questions of law). Before petitioner’s case the question of the statute’s meaning with respect to a prisoner serving consecutive life sentences had not been finally determined. While at first the Parole Board and the then Attorney General thought Lerner was eligible within ten years, they did so as a matter of construing the statute, not in exercise of any power of their own to legislate in such matters.
Lerner,
It is a fact of life, unlikely soon to be altered, that new laws are often not challenged and finally interpreted until a number of years go by.
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*440 We would be most reluctant to hold that the due process clause of the Constitution took away from the State of Rhode Island the power to consider and apply its laws correctly in this situation. Only in rare circumstances have courts allowed the misconstructions of officials to stop the proper execution of state or federal law, and such cases have involved prejudice and harm beyond frustrated expectations.
Lerner,
However, in
Devine v. New Mexico Department of Corrections,
The Tenth Circuit Court of Appeals agreed with petitioner’s constitutional challenge to the retrospective application of the
Quintana
decision and held that “the New Mexico Supreme Court violated the due process clause of the Fourteenth Amendment because the manner in which it applied New Mexico parole statutes to [petitioner] was unforeseeable and the decision retroactively enhanced [petitioner’s] punishment.”
Devine,
The official compilation of the statutes of New Mexico stated that the mandatory prison term on a life sentence was ten years. The only indication to the contrary was an oblique reference in the compiler’s notes that an inconsistent provision had been passed by the 1977 legislature.
Devine,
We conclude that, under the principles as discussed above, the application of this court’s decision in
Thiret
to petitioner is not constitutionally proscribed. The key test in determining whether the due process clause precludes the retrospective application of a judicial decision in a criminal case is whether the decision was sufficiently foreseeable so that the defendant had fair warning that the interpretation given the relevant statute by the court would be applied in his case.
See Bouie,
We also reject the petitioner’s equal protection challenge. In this connection, we agree with the reasoning of the Supreme Judicial Court of Maine in
Chestnut v. State,
III.
Because we find that our opinion in Thir-et v. Kautzky is determinative of the issues presented by this case, and because we reject petitioner’s arguments that the interpretation of the parole provisions adopted by the Thiret opinion cannot be applied as to him, we affirm the judgment of the district court.
Notes
. The offenses for which Aue was convicted were committed between June 1 and July 13, 1981.
. We agree that the Parole Board formerly interpreted the relevant parole provisions in the manner now urged by Aue. Although there was no evidentiary hearing in this case, in Thiret the trial court found such interpretation to exist and we specifically upheld this finding. Thiret, at 806. As Thiret indicates, for ten years the Parole Board erroneously interpreted these provisions as requiring mandatory parole for all sex offenders except those sentenced under the Sex Offenders Act. The Parole Board changed its interpretation in response to an oral opinion which it received in January 1989 from an assistant attorney general advising the Parole Board that its interpretation of the statutes was in error. At 803. We upheld the Parole Board's current construction of the parole provisions in Thiret. There had been no prior judicial interpretation of the relevant statutory language.
. In
City of Columbia v. Bouie,
