The opinion of the court was delivered by: MORAN
JAMES B. MORAN, UNITED STATES DISTRICT JUDGE
Petitioner Clarence Walker ("Walker"), an inmate in the Stateville Correctional Center, filed a pro se petition for a writ of habeas corpus based on various constitutional infirmities allegedly attending the calculation of his sentence, his good-time credits and his eligibility for parole. Before this court is a motion for summary judgment filed by respondent Michael O'Leary ("O'Leary"), the warden at Stateville, and a cross-motion filed by Walker. For the reasons set forth below, Walker's motion is denied, and O'Leary's motion is granted in part.
Walker was arrested on September 20, 1966 and convicted in a March 3, 1968 bench trial of rape, armed robbery, and attempted murder, for which he was sentenced to consecutive terms of 100 to 150 years, 100 to 150 years, and 19 to 20 years, respectively. Following an unsuccessful direct appeal, People v. Walker, 2 Ill.App.3d 1026, 279 N.E.2d 23 (1971), and a denial of his petition for leave to appeal to the Illinois Supreme Court, Walker petitioned for post-conviction relief, and the judgment of the Cook County Circuit Court dismissing this petition was affirmed at the appellate level, People v. Walker, 6 Ill.App.3d 909, 286 N.E.2d 812 (1972). Leave to appeal to the Illinois Supreme Court was again denied on March 29, 1972. Walker's final attempt at direct review, a petition for a writ of certiorari, was denied by the United States Supreme Court on February 20, 1973. Walker v. Illinois, 410 U.S. 941, 35 L. Ed. 2d 608, 93 S. Ct. 1377 (1973).
After serving approximately twenty years of his sentence, Walker filed a petition for a writ of mandamus, alleging many of the same constitutional violations that are now at issue. Specifically, Walker argued that the Illinois Department of Corrections ("the Department") had unconstitutionally denied him good-time credits for the period that he had served prior to his conviction; that the Department had improperly neglected to apply prospectively the 1978 change in the good-time credit system, allowing for day-to-day good-time credits, and that it had failed to apply both that system and a 1973 good-time credit enactment retrospectively; that it had failed to recalculate his sentence pursuant to the Uniform Corrections Code even though his case had not reached final adjudication as of January 1, 1973, the effective date of the Code; and finally, that it had incorrectly determined his parole eligibility date. The Circuit Court ruled against Walker on all claims at the summary judgment stage, and this judgment was upheld in a cursory opinion by the Illinois Appellate Court. Walker v. Lane, 141 Ill. App. 3d 504, 490 N.E.2d 707, 95 Ill. Dec. 854 (1987). Walker's petition for leave to appeal to the Illinois Supreme Court was denied for a third time. Walker now seeks from this court a writ of habeas corpus based on the constitutional claims asserted at the mandamus level and on the additional argument that parole criteria enacted subsequent to the commission of Walker's criminal act were used to determine his eligibility in violation of the Constitution's prohibition of ex post facto laws.
At the time that Walker committed the criminal acts from which this action stems, in 1966, good-time credits in Illinois were applied to the minimum and maximum terms of indeterminate sentences according to the "statutory" good-time credit system: pursuant to a general good-time credit statute, the Department of Corrections established a system whereby a prisoner could receive one month of good-time credit for his first year of imprisonment, two months the second year, and similar increases until his sixth year, after which he could receive six months annually. Supplementing this system, a "compensatory" good-credit scheme was established pursuant to new statutory authority effective January 1, 1973, Ill.Rev.Stat. ch. 38, para. 1003-12-5 (1973); under this system, a prisoner could now receive, in addition to the statutory credits, 7 1/2 days per month for performing work assignments. See generally Johnson v. Franzen, 77 Ill.2d 513, 397 N.E.2d 825, 34 Ill. Dec. 153 (1979); Barksdale v. Franzen, 700 F.2d 1138 (7th Cir. 1983).
In 1977, the Illinois legislature amended these authorizing statutes and divested the Department of Corrections of its discretion to establish statutory and compensatory good-time credit rates. Ill.Rev.Stat. ch. 38, paras. 1003-6-3, 1003-12-5 (1979). The amendments, effective February 1, 1978, specifically direct the Department to prescribe
rules and regulations [that] . . . provide that the prisoner shall receive one day of good conduct credit for each day of service in prison for all classes of felonies other than where a sentence of "natural life" has been imposed. Each day of good conduct credit shall reduce by one day the inmate's period of incarceration set by the court.
Ill.Rev.Stat. ch. 38, para. 1003-6-3(a)(2) (1979). See generally Johnson, 77 Ill.2d at 516-17, 397 N.E.2d at 826-27. Compensatory credits were abandoned entirely in favor of a system providing only for monetary compensation to inmates for services performed. The "day-for-day" formula, still in effect, is applied to all prisoners sentenced after its effective date and to prisoners sentenced prior to this date for subsequently served time. See id.; Williams v. Irving, 98 Ill.App.3d 323, 424 N.E.2d 381, 53 Ill. Dec. 746 (1981). For each prisoner sentenced before February 1, 1978, however, the effects of the day-for-day formula on that individual are compared to the effects of the statutory and compensatory system, and to the extent application of the day-for-day system would result in a later final release date, the old system is used to calculate post-1978 credits. Barksdale, 700 F.2d at 1140.
Indeed, to do otherwise -- to apply the new system to the detriment of veteran prisoners -- may violate the ex post facto clause of the U.S. Constitution. Mosley v. Moran, 798 F.2d 182, 184 (7th Cir. 1986); Barksdale, 700 F.2d at 1140 n.2; cf. Weaver v. Graham, 450 U.S. 24, 67 L. Ed. 2d 17, 101 S. Ct. 960 (1981) (finding a new law that changed the availability of good-time credit to violate the ex post facto clause). Walker asserts two constitutional claims related to this good-time statutory structure: first, that he is entitled to application of the 1978 system for time served after its effective date and, second, that he is entitled to retroactive application of the statutory changes, including credits for time served prior to 1973. We consider these claims in order, looking first to whether any error in calculating Walker's good-time credits has occurred and, second, if one has, to whether it rises to the level of constitutional error.
1. Post-1978 Application of the Day-to-day Formula
After an initial struggle with the good-time credit and sentence calculation worksheets, provided to this court without explanation or clarification by O'Leary,
we were able to ascertain to our satisfaction that Walker's post-1978 good-time credits are calculated according to the old statutory and compensatory systems. Walker's allegation that he was unconstitutionally denied application of the day-for-day credit formula since February 1, 1978, implies an argument that the post-1978 system would benefit him more than the statutory and compensatory schemes. In response, O'Leary observes that the "Illinois Appellate Court has already determined that petitioner has received all of the good-time credit that he is entitled to under Illinois law" and goes on to assert -- again relying on the Appellate Court's opinion -- that Walker "has benefitted more from the credit formula now being applied than he would be receiving under alternative statutory formulas." The Appellate Court, however, offers no further proof or reasoning than "the record indicates that [the 1973] credit formula was more beneficial to the petitioner than either the pre-1973 system or the day-for-day system introduced in 1978."
Were it universally true that the day-for-day system is less beneficial than the earlier system, or were this fact only specifically true with respect to Walker but easily gleaned from the record, O'Leary's naked assertion might be sufficient. But past cases clearly establish that the question of which system is more beneficial is a prisoner-specific inquiry, see Barksdale, 700 F.2d at 1140 ("for some prisoners, application of the new day-to-day formula resulted in a longer period of incarceration" (emphasis added)); Williams, 98 Ill.App.3d at 326, 424 N.E.2d at 384; indeed, in Johnson, application of the day-to-day formula resulted in a shorter sentence. 77 Ill.2d at 518, 397 N.E.2d at 827. Moreover, the procedure used to credit a prisoner's sentence with his good-time awards is far from intuitive.
And the method established to calculate and compare the effects of the two systems is similarly complex. See Williams, 98 Ill.App.3d at 325-26, 424 N.E.2d at 383. O'Leary's motion for summary judgment, therefore, should have been accompanied by an affidavit verifying its assertion that the pre-1978 system was more advantageous to Walker and explaining how this result was reached.
Rather than delay the adjudication of this claim, however, this court has undertaken the task of calculating the effects of the two systems itself. We find that under the day-for-day system, Walker is scheduled for final release in approximately January, 2134, compared with his projected release date under the old system of March 31, 2124 as of December, 1988.
The Department of Correction's refusal to apply the day-for-day formula to Walker's sentence is consistent with Illinois law and constitutes no error; Walker's allegation that the Department's conduct violates the Due Process Clause of the Fourteenth Amendment is consequently untenable.
We pause here briefly to analyze in greater detail Walker's argument that non-application of the day-for-day system violates the ex post facto clause. Our finding that use of the day-for-day formula with respect to Walker's sentence would push back his final release date and therefore work to his detriment compels the conclusion that no ex post facto violation occurred; quite the contrary, application of the new system would be constitutionally suspect. We also note, however, that Walker's argument reflects a fundamental misunderstanding of the purpose of the ex post facto clause and of what triggers a violation. Walker claims that non-application of a subsequently enacted statute that may benefit him runs afoul of the ex post facto clause. But the protection afforded by this clause is much more limited than Walker seems to think: it forbids the enactment of any law "'which imposes a punishment for an act which was not punishable at the time it was committed; or imposes additional punishment to that then prescribed.'" Weaver v. Graham, 450 U.S. 24, 28, 67 L. Ed. 2d 17, 101 S. Ct. 960 (1981) (citing Cummings v. Missouri, 71 U.S. 277, 4 Wall. 277, 325-26, 18 L. Ed. 356 (1867)). The effect of the prohibition on ex post facto laws is to ensure that the punishment assigned by law at the time the act occurred will be the ceiling on punishment; it simply is not meant to reach any law that may ...