Petitioner-appellant, Robert Breest, (hereinafter petitioner), a convicted New Hampshire state prisoner, appeals from an opinion and order of the United States District Court for the District of New Hampshire denying, in substantial part, relief sought on a petition for a writ of habeas corpus. Accused of killing a young woman on February 28, 1971, petitioner was tried by jury and convicted of first degree murder. On March 22, 1973, the day of the jury's verdict, he was sentenced to life imprisonment and immediately commenced to serve his sentence. On April 5, 1973, petitioner was returned before the trial court and his crime was certified as "psycho-sexual in nature" pursuant to the requirements of NH RSA 607:41-b to d (Supp.1972).1 The effect of that certification was to fix the minimum sentence which petitioner would have to serve before becoming eligible for parole at forty years minus good time credits. During trial and at both sentencing hearings, petitioner was represented by counsel.

Petitioner appealed to the New Hampshire Supreme Court, raising numerous challenges to his conviction and sentence. Of these, three constitute the claims presented here. First, petitioner claims that the application to him of the psycho-sexual murder provisions impermissibly placed him twice in jeopardy. Second, application of those provisions is assailed as violating the prohibition against ex post facto laws. Third, it is claimed that certain evidence used against petitioner at his trial was obtained unlawfully because the warrant authorizing the search was based upon an affidavit allegedly containing intentional misrepresentations of fact. Finding these challenges to be without merit, the New Hampshire Supreme Court affirmed the conviction and sentence. State v. Breest, 116 N.H. 734, 367 A.2d 1320 (1976).

Petitioner then sought federal habeas corpus relief, raising the same issues previously decided in his state appeal. The district court ruled against petitioner on all of his claims except one. The court held that due process requires the state to afford petitioner an evidentiary hearing on the issue of whether the murder was in fact psycho-sexual in nature, before subjecting him to the harsher parole provisions of the psycho-sexual murder statute. The state does not challenge that ruling on this appeal.2 The district court held, however, that the application of the psycho-sexual murder statute violated neither the double jeopardy nor the ex post facto clauses of the Constitution. As to the Fourth Amendment claim, the court found that the "State has provided (petitioner) an opportunity for full and fair litigation", and therefore federal habeas corpus relief on that issue was precluded by Stone v. Powell, 428 U.S. 465, 96 S. Ct. 3037, 49 L. Ed. 2d 1067 (1976). We conclude that petitioner's rights have not been violated and therefore affirm.

Petitioner challenges his sentence under the proscriptions against both the double jeopardy and ex post facto laws. A brief chronology sets the stage for consideration of these claims. On February 28, 1971, the date of the crime, the penalty for first degree murder in New Hampshire was life imprisonment without the possibility of parole. NH RSA 607:43 (1955); NH RSA 585:4 (1955).3 On July 1, 1971, NH RSA 607:41-a became effective, providing that persons serving life sentences would be eligible for parole after serving eighteen years.4 On April 4, 1972, petitioner was indicted for first degree murder. Then, on May 14, 1972, new provisions dealing with psycho-sexual murder took effect, altering parole eligibility in certain first degree murder cases.5 NH RSA 607:41-c (Supp.1972) provided that

"Whenever any person is convicted of murder in the first degree, the presiding justice shall certify, at the time of sentencing, whether or not such murder was psycho-sexual in nature."

If the crime was so certified, the person convicted could not become parole eligible until forty years had been served.

On March 22, 1973, while this provision was in effect,6 petitioner was convicted of first degree murder, sentenced to imprisonment "for life", and began to serve his sentence. At this sentencing, the court neglected to make the required certification, and indeed failed to make any reference to NH RSA 607:41-c.7 Five days later, on March 27, 1973, the state filed a motion for resentencing pursuant to the psycho-sexual murder provisions. Petitioner was returned to the court on April 5, 1973 and, over his objection, the court certified the murder as psycho-sexual. As noted, this had the effect of increasing petitioner's minimum term from eighteen to forty years.8

Petitioner's first claim is that the imposition of a more onerous minimum term at the resentencing hearing on April 5, 1973, violated his right not to be twice placed in jeopardy. As a general rule, an increase in sentence after a defendant has begun to serve his punishment contravenes the prohibition against double jeopardy. See, e. g., Ex Parte Lange, 85 U.S. (18 Wall.) 163, 21 L. Ed. 872 (1874); United States v. Bynoe, 562 F.2d 126, 128 (1st Cir. 1977). In rejecting petitioner's double jeopardy claim, however, both the district court and the New Hampshire Supreme Court invoked a well recognized exception to that rule. In the leading case of Bozza v. United States, 330 U.S. 160, 67 S. Ct. 645, 91 L. Ed. 818 (1947), the trial court, when sentencing a defendant convicted under a statute requiring Both a fine and imprisonment, imposed a prison term only. Five hours after sentence was announced the court realized its mistake, called back the defendant and imposed a fine in addition to the prison term. The Court rejected the contention that the subsequent imposition of the fine to conform the sentence to the statutory requirements constituted double jeopardy. Bozza thus stands for the proposition that "a trial court not only Can alter a statutorily-invalid sentence in a way which might increase its severity, but Must do so when the statute so provides." Thompson v. United States, 495 F.2d 1304, 1306 (1st Cir. 1974) (emphasis in original); United States v. Bishop, 487 F.2d 631, 633 (1st Cir. 1973). See Pollard v. United States, 352 U.S. 354, 361, 77 S. Ct. 481, 1 L. Ed. 2d 393 (1957). Even after the defendant has commenced to serve his sentence, that power and that obligation continue. United States v. Davis, 183 U.S.App.D.C. 121, 561 F.2d 1014, Cert. denied, 434 U.S. 929, 98 S. Ct. 416, 54 L. Ed. 2d 290 (1977); United States v. Stevens, 548 F.2d 1360 (9th Cir.), Cert. denied, 430 U.S. 975, 97 S. Ct. 1666, 52 L. Ed. 2d 369 (1977); Llerena v. United States, 508 F.2d 78 (5th Cir. 1975); See United States v. Becker,536 F.2d 471, 472 (1st Cir. 1976); Fed.R.Crim.P. 35.

The sentence imposed on March 22, 1973 of life imprisonment, without any finding as to whether or not the crime was "psycho-sexual in nature", and if it was, without a certification to that effect setting the minimum term at forty years, was a "statutorily invalid sentence". See State v. Breest, 116 N.H. 734, 367 A.2d 1320, 1335 (1976). As such, the sentence would fall within the Bozza exception and the trial court would not violate petitioner's rights under the double jeopardy clause by correcting it.

Petitioner asserts, however, that Bozza is not applicable since a life sentence without a psycho-sexual certification was a theoretically permissible penalty for first degree murder. This being so, he asserts that the general rule against enhancement of a valid sentence should still apply to bar the resentencing here. See, e. g., United States v. Bynoe, supra; United States v. Turner, 518 F.2d 14 (7th Cir. 1975); United States v. Bowens, 514 F.2d 440 (9th Cir. 1975).

While it may be true that petitioner could have been lawfully imprisoned under a life sentence imposed without reference to the psycho-sexual murder statute, and thus implicitly have been subject to the more lenient eighteen year parole term, we believe it clear that the court had a duty to determine whether the crime was psycho-sexual in nature and if it was, to so certify. The court's failure to do so on March 22, 1973 left the sentence incomplete and, in petitioner's case, potentially more lenient than the statute permitted.9 In that circumstance, the sentence while lawful in the sense that petitioner was and could have remained lawfully incarcerated thereunder was still legally invalid in the sense that it was subject to correction. See United States v. Kenyon, 519 F.2d 1229, 1321-32 (9th Cir.), Cert. denied,423 U.S. 935, 96 S. Ct. 293, 46 L. Ed. 2d 267 (1975); Cf. Cook v. United States, 171 F.2d 567, 569 (1st Cir. 1948), Cert. denied, 336 U.S. 926, 69 S. Ct. 647, 93 L. Ed. 1088 (1949).

An example of the application of this principle is found in our recent decision in Thompson v. United States, supra. There petitioner had been convicted of federal narcotics offenses in violation of 21 U.S.C. §§ 841(a)(1), 846 (1970), was sentenced to, and began serving, a prison term. Some time thereafter, the Bureau of Prisons notified the court that in sentencing petitioner, it had failed to include a "special parole term", as required by 21 U.S.C. § 841(b)(1)(A) (1970). In response, the court amended petitioner's sentence to include a three year special parole term. On appeal we upheld the amended sentence against a double jeopardy challenge on the ground that the trial court not only could correct the sentence to comply with the statutory requirements without violating petitioner's rights, but indeed had a duty to do so. 495 F.2d at 1306. Our position in Thompson has been embraced by several other circuits. United States v. Davis, 183 U.S.App.D.C. 121, 125, 561 F.2d 1014, 1018, Cert. denied, 434 U.S. 929, 98 S. Ct. 416, 54 L. Ed. 2d 290 (1977); Bell v. United States, 521 F.2d 713, 716 (4th Cir. 1975), Cert. denied, 424 U.S. 918, 96 S. Ct. 1121, 47 L. Ed. 2d 324 (1976); United States v. Kenyon, supra; United States v. Richardson, 498 F.2d 9, 10 (8th Cir.), Cert. denied, 419 U.S. 1020, 95 S. Ct. 494, 42 L. Ed. 2d 294 (1974); Garcia v. United States, 492 F.2d 395, 397-98 (10th Cir.), Cert. denied, 419 U.S. 897, 95 S. Ct. 178, 42 L. Ed. 2d 142 (1974); Caille v. United States, 487 F.2d 614, 616 (5th Cir. 1973); United States v. Thomas, 474 F.2d 1336 (2d Cir. 1973), Aff'g 356 F. Supp. 173, 174 (E.D.N.Y.1972). In applying the law of these cases to the present case, Judge Goodwin's comments in United States v. Kenyon, supra, are particularly instructive:

"Sentences which are defective because they fail to impose a minimum required penalty should be viewed as voidable by the court, either on its own motion or at the request of the government. But such sentences are fully effective unless and until they are voided by the court.

"When a judge has omitted entirely a category of punishment mandated by statute, he has not exercised the discretion with respect to that punishment which the statute contemplates. We do not read the double jeopardy clause to preclude the exercise of such discretion on resentencing." 519 F.2d at 1232-33 (footnote omitted).10

We do not consider it to be of significance to our decision whether the trial court's error is characterized as the imposition of an "illegal sentence", or the imposition of a legal sentence in an "illegal manner" due to the court's failure to make the required certification. In either case, the double jeopardy clause does not preclude the court from bringing the sentence and the manner of its imposition into compliance with statutory requirements. See United States v. Stevens, supra, 548 F.2d at 1362 & n.8.11 Fed.R.Crim.P. 35.

Because the trial court had a duty under the statute, its failure to fulfill that duty left the original sentence legally incomplete.12 We stress that this is not a case where the sentencing court attempts to increase a defendant's sentence on the basis of mistakes of fact, See, e. g., United States v. Bynoe, supra, or simply a change of heart. Nor is this a case where the court in correcting the sentence exercised any discretion which could have been used vindictively or for improper purposes. See North Carolina v. Pearce, 395 U.S. 711, 723-26, 89 S. Ct. 2072, 23 L. Ed. 2d 656 (1969); Blankenship v. Parratt, 554 F.2d 850, 852 (8th Cir. 1977); Jones v. United States, 538 F.2d 1346, 1348 (8th Cir. 1976). The New Hampshire statute involved here required the court to make a finding of fact; if that finding was in the affirmative, a particular penalty inexorably followed. Thus, the danger of unfairness to, or harassment of petitioner through correction of his sentence was minimal. Conversely, the state's interest in the imposition of the legislatively established punishment for this serious crime is strong.

Before leaving this question, we note our concern that the power of a sentencing court to correct even a statutorily invalid sentence must be subject to some temporal limit. When a prisoner first commences to serve his sentence, especially if it involves a long prison term as here, the prospect of release on parole or otherwise may seem but a dimly perceived, largely unreal hope. As the months and years pass, however, the date of that prospect must assume a real and psychologically critical importance. The prisoner may be aided in enduring his confinement and coping with the prison regime by the knowledge that with good behavior release on parole or release outright will be achieved on a date certain. After a substantial period of time, therefore, it might be fundamentally unfair, and thus violative of due process for a court to alter even an illegal sentence in a way which frustrates a prisoner's expectations by postponing his parole eligibility or release date far beyond that originally set. We need not decide, however, how long or under what circumstances the state or a sentencing court constitutionally can wait to enhance an invalid sentence. The short period of time involved here clearly was permissible.

Petitioner next assails his sentence as contrary to the constitutional proscription against ex post facto laws. Article I, section 10. He concedes that on February 28, 1971, the date of the killing, the penalty for first degree murder in New Hampshire was life imprisonment without possibility of parole a penalty substantially harsher than he actually received.13 Further, he concedes that on March 22, 1973, the day of his conviction and original sentencing, the law provided for a penalty of life imprisonment with parole eligibility after forty years for a person convicted of first degree murder found to be psycho-sexual in nature. Petitioner, however, asserts constitutional error based upon the facts that (1) the psycho-sexual murder provisions were enacted subsequent to the crime; and (2) on the day he was indicted, the statute establishing eighteen year parole eligibility for life sentences had taken effect but the qualification to that provision in the case of psycho-sexual murders, though enacted, had not yet become effective.

Both the New Hampshire Supreme Court and the district court rejected this claim on the ground that the law under which petitioner was sentenced was less onerous than the law in effect at the time of the crime and thus not a violation of the ex post facto clause.

The constitutional ban on ex post facto laws reaches (1) every law which makes criminal an act done before its enactment which was legal when performed; (2) every law that aggravates a crime or makes it greater than it was when committed; (3) every law that changes the punishment and inflicts a greater punishment than the law affixed to the crime when committed; and (4) every law that alters the legal rules of evidence and receives less, or different evidence than the law required at the time of the commission of the offense, in order to convict the offender; or (5) otherwise, any change in a law in relation to the offense or its consequences, that alters the situation of a party to his disadvantage. Calder v. Bull, 3 U.S. (3 Dall.) 385, 390,1 L.Ed. 648 (1798); Malloy v. South Carolina, 237 U.S. 180, 183-85, 35 S. Ct. 507, 59 L. Ed. 905 (1915); Lindsey v. Washington, 301 U.S. 397, 401, 57 S. Ct. 797, 81 L. Ed. 1182 (1936).

Subsequent elaborations of the ex post facto clause have made it clear that parole eligibility constitutes part of punishment and thus that a retroactively applied change in eligibility to the disadvantage of a prisoner may at least in some circumstances be unconstitutional. See Shepard v. Taylor,556 F.2d 648 (2d Cir. 1977); Greenfield v. Scafati, 277 F. Supp. 644 (D.Mass.1967), Aff'd mem., 390 U.S. 713, 88 S. Ct. 1409, 20 L. Ed. 2d 250 (1968). From the earliest judicial construction to the present, however, it has also been clear that application of a law, enacted after the crime, which changes the punishment, is not in and of itself unconstitutional. Only those which inflict greater or additional punishment are banned. As Mr. Justice Chase noted,

"I do not consider any law Ex post facto, within the prohibition, that mollifies the rigor of the criminal law; but only those that create, or aggravate, the crime; or increase the punishment, or change the rules of evidence, for the purpose of conviction." Calder v. Bull, supra, 3 U.S. (3 Dall) at 390.

See Dobbert v. Florida, 432 U.S. 282, 292-94, 97 S. Ct. 2290, 53 L. Ed. 2d 344 (1977); United States v. Palladino, 490 F.2d 499, 501 n.7 (1st Cir. 1974); Commonwealth v. Vaughn, 329 Mass. 333, 339, 108 N.E.2d 559, 563 (1952).

Against these principles, petitioner's argument must fail. We shall assume that if, on the date of the killing, the penalty for first degree murder had been life with parole eligibility in eighteen years, application of a provision increasing the minimum term to forty years would have been unconstitutional. See, e. g., Lindsey v. Washington, supra. However, that was not what happened here. When petitioner committed the act for which he was convicted, the penalty for that crime was life without parole. Subsequently, the law was changed to provide that persons serving life sentences could be parole eligible in eighteen years, except those convicted of a first degree murder that was psycho-sexual in nature, whose minimum term was set at forty years. These statutory changes did not make criminal an act innocent when committed, nor did they aggravate the crime. While the punishment affixed to the crime was altered, the change was ameliorative, regardless of whether or not the psycho-sexual provisions were applied.14 And while there was a modification of the evidence relevant to sentencing, neither the rules of evidence nor the elements required for a first degree murder conviction were changed. See Todd v. Stynchcombe, 486 F.2d 1030 (5th Cir. 1973); Ward v. State of California, 269 F.2d 906, 907-08 (9th Cir. 1959); People v. Ward, 50 Cal. 702, 328 P.2d 777 (1958), Cert. denied,359 U.S. 945, 79 S. Ct. 730, 3 L. Ed. 2d 678 (1958); People v. Warden, 43 Misc. 2d 109, 250 N.Y.S.2d 15, 19-23, Aff'd mem., 15 N.Y.2d 663, 255 N.Y.S.2d 876, 204 N.E.2d 206 (1964), Cert. denied, 380 U.S. 937, 85 S. Ct. 948, 13 L. Ed. 2d 824 (1965). In sum, the New Hampshire law as applied to petitioner was neither "more onerous than the prior law" nor disadvantageous in any respect. No violation of the bar against ex post facto laws occurred. Dobbert v. Florida, supra; Commonwealth v. Vaughn, supra.

Acknowledging these shortcomings in his position, petitioner nonetheless asks us to test his claim not by comparing the law in effect on the date of the murder to that under which he was sentenced, but rather that in effect on the day he was indicted. On that date, April 4, 1972, the statute providing for the eighteen year parole eligibility had taken effect. The provision establishing a forty year minimum for psycho-sexual murders, while enacted on March 15, 1972, did not, however, become effective until May 14, 1972.

Petitioner had no inherent right to be sentenced under the eighteen year minimum sentence provisions, simply because they were in effect on the date of his indictment. Petitioner suggests that the state should be estopped from applying anything but the eighteen year provisions, because it sought to have him resentenced upon discovering that the original sentence failed to include the required certification. We see no reason to construe the state's actions here as constituting a concession that petitioner would be sentenced under the eighteen year provision without reference to the psycho-sexual murder provisions. At most, the state's conduct at the original sentencing manifested ignorance of all the relevant statutory requirements. Moreover, even assuming such a concession by the state, petitioner has established neither reliance nor prejudice to justify an estoppel.

No policy underlying the interdiction of ex post facto laws requires a different result. First, petitioner clearly had adequate notice that the deliberate and premeditated killing of another constituted first degree murder in New Hampshire on February 28, 1971, and that the state considered the crime serious enough to warrant life imprisonment. That the state later decided to treat first degree murderers more leniently, but some even more leniently than others, does not render petitioner's notice inadequate.15 Cf. Commonwealth v. Vaughn, supra. Second, there is no basis on this record for concern about politically motivated retroactive retribution. The psycho-sexual murder provisions were enacted before petitioner's indictment. While petitioner apparently was the only person sentenced thereunder, he also was the only person convicted of first degree murder in New Hampshire while the statute was in effect. When it was repealed, the mandatory life sentence for first degree murder was reinstated. Thus, petitioner, rather than being singled out for harsher treatment, appears to have been the single beneficiary of the state's experiment with greater leniency.The Fourth Amendment Claim

Petitioner's final ground for relief may be disposed of quickly. He maintains that the trial court erred in failing to exclude certain evidence obtained on the basis of an allegedly defective affidavit in that facts tending to negate probable cause were deliberately omitted by law enforcement officers. We do not reach the merits of this claim. We agree with the district court that the state courts afforded petitioner "an opportunity for full and fair litigation" of his Fourth Amendment claim. Therefore, relief is not available under 28 U.S.C. § 2254. Stone v. Powell, 428 U.S. 465, 96 S. Ct. 3037, 49 L. Ed. 2d 1067 (1976); Dupont v. Hall, 555 F.2d 15, 17 (1st Cir. 1977); United States ex rel. Petillo v. State of New Jersey, 562 F.2d 903, 906 (3d Cir. 1977); Cole v. Estelle, 548 F.2d 1164 (5th Cir. 1977); Holmberg v. Parratt,548 F.2d 745 (8th Cir.), Cert. denied, 431 U.S. 969, 97 S. Ct. 2930, 53 L. Ed. 2d 1066 (1977).

Affirmed.