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                       Nebraska A dvance Sheets
                        291 Nebraska R eports
                              CATON v. STATE
                             Cite as 291 Neb. 939




                     Bruce Caton, appellant, v.
                    State of Nebraska, appellee.
                                ___ N.W.2d ___

                    Filed October 2, 2015.    No. S-14-1144.

 1.	 Judgments: Appeal and Error. When reviewing questions of law, an
     appellate court resolves the questions independently of the conclusion
     reached by the lower court.
 2.	 Habeas Corpus. The habeas corpus writ provides illegally detained
     prisoners with a mechanism for challenging the legality of a person’s
     detention, imprisonment, or custodial deprivation of liberty.
 3.	 Habeas Corpus: Probation and Parole. A parolee may seek relief
     through Nebraska’s habeas corpus statute.
 4.	 Constitutional Law: Criminal Law: Statutes: Sentences. The ex post
     facto prohibitions found in the Ex Post Facto Clauses of U.S. Const.
     art. I, § 10, and Neb. Const. art. I, § 16, forbid Congress and the states
     from enacting 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.
 5.	 Constitutional Law: Judgments. The Ex Post Facto Clauses do not
     concern judicial decisions.
 6.	 Constitutional Law: Judgments: Due Process. Limitations on ex post
     facto judicial decisionmaking are inherent in the notion of due process,
     and retroactive judicial decisionmaking may be analyzed in accordance
     with the more basic and general principle of fair warning under the Due
     Process Clause.
 7.	 Judgments: Due Process. Under the Due Process Clause, the ques-
     tion is whether the judicial decision being applied retroactively is both
     unexpected and indefensible by reference to the law which had been
     expressed prior to the conduct in issue.
 8.	 Sentences. Good time reductions under Neb. Rev. Stat. § 83-1,107
     (Reissue 2014) do not apply to mandatory minimum sentences.
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                         Nebraska A dvance Sheets
                          291 Nebraska R eports
                                CATON v. STATE
                               Cite as 291 Neb. 939

  9.	 ____. Logically, a defendant must serve the mandatory minimum por-
      tion of a sentence before earning good time credit toward the maximum
      portion of the sentence.
10.	 ____. A defendant is unable to earn good time credit against either the
      minimum or maximum sentence until the defendant has served the man-
      datory minimum sentence.

  Appeal from the District Court for Lancaster County: Steven
D. Burns, Judge. Affirmed.

      Bruce Caton, pro se.

   Douglas J. Peterson, Attorney General, and George R. Love
for appellee.

  Wright, Connolly, McCormack, Miller-Lerman, and
Cassel, JJ., and Moore, Chief Judge, and R iedmann, Judge.

      McCormack, J.
                      NATURE OF CASE
   Bruce Caton was discharged from the custody of the
Department of Correctional Services (Department) upon serv-
ing 10 years of his sentence. Caton was later taken back into
custody after the Department realized that the mandatory
discharge date had been erroneously calculated by giving
good time credit on the 10-year mandatory minimum term of
Caton’s sentence. Caton filed a petition for a writ of habeas
corpus, challenging the Department’s continuing exercise
of custody. Caton alleged that in calculating his manda-
tory discharge date, the Department’s reliance on State v.
Castillas1 violated the prohibition against ex post facto laws.
The district court granted summary judgment for the State.
We affirm.

 1	
      State v. Castillas, 285 Neb. 174, 826 N.W.2d 255 (2013), disapproved on
      other grounds, State v. Lantz, 290 Neb. 757, 861 N.W.2d 728 (2015).
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                  Nebraska A dvance Sheets
                   291 Nebraska R eports
                         CATON v. STATE
                        Cite as 291 Neb. 939

                        BACKGROUND
   Caton was sentenced on October 27, 2004, to 10 to 20
years’ imprisonment with 363 days’ credit for time served,
after being convicted of burglary with habitual criminal
enhancement. An order of commitment into the custody of the
Department was signed by the clerk of the district court that
same date. The date Caton committed the acts that led to this
conviction is not in the record. The 10-year minimum sen-
tence was mandatory under the habitual criminal statute, Neb.
Rev. Stat. § 29-2221 (Reissue 1995).
   The State discharged Caton after erroneously calculating
good time on the 10-year mandatory minimum sentence. The
correct mandatory discharge date will be upon serving 15 years
of his sentence. Approximately 8 months after Caton’s errone-
ous discharge, Caton was brought back into the Department’s
custody after the district court granted the State’s motion to
secure an arrest warrant. Caton was immediately released on
parole. An affidavit by the records manager of the Department
reflects that the Department has for purposes of his mandatory
discharge date given Caton credit for the time spent mistak-
enly at liberty.
   Caton filed a petition for a writ of habeas corpus. Caton
argued that in calculating his discharge date, the Department’s
reliance on Castillas, in which we discussed how discharge and
parole eligibility dates should be calculated under the relevant
good time statutes, violated the prohibition against ex post
facto laws.2 The court granted the State’s motion for summary
judgment. Caton appeals.

                ASSIGNMENTS OF ERROR
  Caton assigns as error: (1) “Due Process cannot be refused
on the basis of a person’s possible choice to flee jurisdiction,
or a right to appeal,” and (2) a “Nebraska Supreme Court

 2	
      Id.
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                         Nebraska A dvance Sheets
                          291 Nebraska R eports
                                CATON v. STATE
                               Cite as 291 Neb. 939

opinion issued in 2002 cannot ‘foretell’ an opinion of 2013
where the meaning of a law is altered to limit good time credit
causing arrest and re-incarceration for 5 more years, 8 months
after discharge from sentence for crime commit[t]ed 91⁄2 years
before 2013 definition.”
                  STANDARD OF REVIEW
   [1] When reviewing questions of law, an appellate court
resolves the questions independently of the conclusion reached
by the lower court.3
                            ANALYSIS
   [2] The habeas corpus writ provides illegally detained pris-
oners with a mechanism for challenging the legality of a
person’s detention, imprisonment, or custodial deprivation of
liberty.4 The State agrees that habeas corpus was the proper
procedure for Caton to challenge the Department’s exercise
of custody.
   [3] Although Caton was a parolee, we have held in other
contexts that a parolee is “in custody under sentence.” In State
v. Thomas,5 we reasoned:
      [A parolee] is subject to revocation of his parole and
      return to prison if he violates the terms of his parole in
      any way. . . . As a condition of parole he may be required
      to be employed, remain in a certain geographical area
      unless granted written permission to leave the area, report
      to his parole officer, submit to certain medical or psycho-
      logical treatment, refrain from associating with certain
      persons, or abide by any other conditions determined by
      the Board of Parole. [A parolee] does not possess the

 3	
      State v. Armagost, 291 Neb. 117, 864 N.W.2d 417 (2015).
 4	
      Anderson v. Houston, 274 Neb. 916, 744 N.W.2d 410 (2008); Tyler v.
      Houston, 273 Neb. 100, 728 N.W.2d 549 (2007). See, also, Neb. Rev. Stat.
      § 29-2801 (Reissue 2008).
 5	
      State v. Thomas, 236 Neb. 553, 557, 462 N.W.2d 862, 866 (1990)
      (citations omitted).
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                           291 Nebraska R eports
                                 CATON v. STATE
                                Cite as 291 Neb. 939

      same degree of liberty and freedom as a citizen not under
      the jurisdiction of the Board of Parole.
We also noted in Thomas that the U.S. Supreme Court, in
Jones v. Cunningham,6 held that a parolee is “‘in custody’” for
purposes of the federal habeas corpus statute.7 The majority
view in other jurisdictions is that parole is a sufficient restraint
of liberty as will entitle a petitioner to relief.8 We similarly
hold here that a parolee may seek relief through our habeas
corpus statute.
   Caton argues that the Department’s application of our
opinion in Castillas, explaining how good time should be
calculated for mandatory minimum sentences,9 violated the
prohibition against ex post facto laws, because such inter-
pretation was “‘[u]nforeseeable.’”10 Caton makes no other
fully articulated argument that was both assigned as error and

 6	
      Jones v. Cunningham, 371 U.S. 236, 83 S. Ct. 373, 9 L. Ed. 2d 285 (1963).
 7	
      Id., 371 U.S. at 238, quoting 28 U.S.C. § 2241 (1958).
 8	
      See, Mainali v. Virginia, 873 F. Supp. 2d 748 (E.D. Va. 2012); Banks v.
      Gonzales, 496 F. Supp. 2d 146 (D.D.C. 2007); In re Wessley W., 125 Cal.
      App. 3d 240, 181 Cal. Rptr. 401 (1981); Schooley v. Wilson, 150 Colo.
      483, 374 P.2d 353 (1962); Carnley v. Cochran, 123 So. 2d 249 (Fla. 1960),
      reversed on other grounds 369 U.S. 506, 82 S. Ct. 884, 8 L. Ed. 2d 70
      (1962); In re Application of Horst, 270 Kan. 510, 14 P.3d 1162 (2000);
      Staples v. State, 274 A.2d 715 (Me. 1971); State ex rel. Atkinson v. Tahash,
      274 Minn. 65, 142 N.W.2d 294 (1966); State v. Gray, 406 S.W.2d 580
      (Mo. 1966); Garnick v. Miller, 81 Nev. 372, 403 P.2d 850 (1965); Com. ex
      rel. Ensor v. Cummings, 420 Pa. 23, 215 A.2d 651 (1966); Ex parte Elliott,
      746 S.W.2d 762 (Tex. Crim. 1988); Monohan v. Burdman, 84 Wash. 2d
      922, 530 P.2d 334 (1975). But see, Williams v. State, 42 Ala. App. 140,
      155 So. 2d 322 (1963); Sorrow v. Vickery, 228 Ga. 191, 184 S.E.2d 462
      (1971); People ex rel. Williams v. Morris, 44 Ill. App. 3d 39, 357 N.E.2d
      851, 2 Ill. Dec. 631 (1976); McGloin v. Warden, 215 Md. 630, 137 A.2d
      659 (1958); State v. Ballard, 15 N.J. Super. 417, 83 A.2d 539 (1951);
      People ex rel. Ali v. Sperbeck, 66 A.D.2d 827, 411 N.Y.S.2d 344 (1978);
      Ex parte Davis, 11 Okla. Crim. 403, 146 P. 1085 (1915); White v. Gladden,
      209 Or. 53, 303 P.2d 226 (1956).
 9	
      State v. Castillas, supra note 1.
10	
      Brief for appellant at 10.
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                          Nebraska A dvance Sheets
                           291 Nebraska R eports
                                 CATON v. STATE
                                Cite as 291 Neb. 939

preserved below, challenging the current custodial deprivation
of liberty.11
   [4] The Ex Post Facto Clause provides simply that “[n]o
State shall . . . pass any . . . ex post facto law.”12 The ex post
facto prohibitions found in the Ex Post Facto Clauses of U.S.
Const. art. I, § 10, and Neb. Const. art. I, § 16, forbid Congress
and the states from enacting 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.”’”13 Stated another way, the Ex Post Facto Clauses
“‘“forbid[] the application of any new punitive measure to a
crime already consummated.”’”14
   The Ex Post Facto Clauses ensure that individuals have
fair warning of applicable laws, and the clauses guard against
vindictive legislative action.15 Even where these concerns are
not directly implicated, the clauses also safeguard “‘“a fun-
damental fairness interest . . . in having the government abide
by the rules of law it establishes to govern the circumstances
under which it can deprive a person of his or her liberty
or life.”’”16
   In Weaver v. Graham,17 the U.S. Supreme Court held that it
is a violation of the prohibition against ex post facto laws to
apply a new formula for calculating future good time credits

11	
      See, State v. Huston, 285 Neb. 11, 824 N.W.2d 724 (2013); State v. Paul,
      256 Neb. 669, 592 N.W.2d 148 (1999).
12	
      U.S. Const. art. I, § 10, cl. 1.
13	
      Shepard v. Houston, 289 Neb. 399, 410, 855 N.W.2d 559, 568 (2014),
      quoting Weaver v. Graham, 450 U.S. 24, 101 S. Ct. 960, 67 L. Ed. 2d 17
      (1981).
14	
      Id., quoting California Dept. of Corrections v. Morales, 514 U.S. 499, 115
      S. Ct. 1597, 131 L. Ed. 2d 588 (1995).
15	
      Shepard v. Houston, supra note 13.
16	
      Id. at 410, 855 N.W.2d at 568, quoting Peugh v. U.S., ___ U.S. ___, 133
      S. Ct. 2072, 186 L. Ed. 2d 84 (2013).
17	
      Weaver v. Graham, supra note 13.
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                        Nebraska A dvance Sheets
                         291 Nebraska R eports
                               CATON v. STATE
                              Cite as 291 Neb. 939

to a person incarcerated for a crime committed before the new
law was passed.
   [5] However, Caton challenges the alleged retroactive
application of our decision in Castillas interpreting our good
time statutes, not any change to the statutes themselves.
Technically, the Ex Post Facto Clauses do not concern judicial
decisions. “As the text of the [Ex Post Facto] Clause makes
clear, it ‘is a limitation upon the powers of the Legislature,
and does not of its own force apply to the Judicial Branch
of government.’”18
   [6,7] Nevertheless, limitations on ex post facto judicial
decisionmaking are inherent in the notion of due process, and
retroactive judicial decisionmaking may be analyzed in accord­
ance with the more basic and general principle of fair warn-
ing under the Due Process Clause.19 Under the Due Process
Clause, the question is whether the judicial decision being
applied retroactively is both unexpected and indefensible by
reference to the law which had been expressed prior to the
conduct in issue.20
   We have explained that indefensible in this context means
“‘incapable of being justified or excused.’”21 Thus, “where a
court interprets a statute in a surprising manner that has little
in the way of legal support, the interpretation could not be
applied retroactively.”22
   Neb. Rev. Stat. § 83-1,107(2)(a) (Reissue 2014) concerns
calculation of the mandatory discharge date in light of good
time. Under § 83-1,107(2)(a), a prisoner’s term of confine-
ment shall be reduced by 6 months for each year of the
committed offender’s term and pro rata for any part thereof

18	
      Rogers v. Tennessee, 532 U.S. 451, 456, 121 S. Ct. 1693, 149 L. Ed. 2d
      697 (2001).
19	
      See, id.; State v. Redmond, 262 Neb. 411, 631 N.W.2d 501 (2001).
20	
      State v. Redmond, supra note 19.
21	
      Id. at 420, 631 N.W.2d at 508.
22	
      Id.
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                           Nebraska A dvance Sheets
                            291 Nebraska R eports
                                  CATON v. STATE
                                 Cite as 291 Neb. 939

which is less than a year. Under § 83-1,107(2)(c), the total
reductions under § 83-1,107(2) shall be credited from the
date of sentence and shall be deducted from the maximum
term, to determine the date when discharge from the custody
of the state becomes mandatory. Also, under Neb. Rev. Stat.
§ 83-1,108 (Reissue 2014), a parolee’s parole term shall be
reduced by the Board of Parole for good conduct while under
parole by 10 days for each month. Such reduction shall be
deducted from the maximum term, less good time granted
pursuant to § 83-1,107, to determine the date when discharge
from parole becomes mandatory.
   Neb. Rev. Stat. § 83-1,110 (Reissue 2014) states in relevant
part that every committed offender shall be eligible for parole
when the offender has served one-half the minimum term of his
or her sentence as provided in §§ 83-1,107 and 83-1,108, but
that “[n]o such reduction of sentence shall be applied to any
sentence imposing a mandatory minimum term.” (Emphasis
supplied.) Section 83-1,110 is the only statute that specifically
refers to the relationship between any statutory reductions and
a mandatory minimum term.
   [8-10] We said in Castillas that § 83-1,110 makes clear
that good time reductions under § 83-1,107 do not apply to
mandatory minimum sentences.23 We further explained that,
logically, a defendant must serve the mandatory minimum
portion of a sentence before earning good time credit toward
the maximum portion of the sentence.24 Thus, a defendant is
unable to earn good time credit against either the minimum
or maximum sentence until the defendant has served the man-
datory minimum sentence.25 We set forth the following rule
of calculation:
      [T]he parole eligibility date is determined by subtract-
      ing the mandatory minimum sentence from the court’s

23	
      State v. Castillas, supra note 1.
24	
      Id.
25	
      Id.
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                           291 Nebraska R eports
                                 CATON v. STATE
                                Cite as 291 Neb. 939

      minimum sentence, halving the difference, and adding
      that difference to the mandatory minimum. Similarly, the
      mandatory discharge date is computed by subtracting the
      mandatory minimum sentence from the maximum sen-
      tence, halving the difference, and adding that difference
      to the mandatory minimum.26
   Before Castillas, we explained in Johnson v. Kenney27 that
while § 83-1,110 does not specifically refer to the mandatory
discharge date, logic and the legislative history dictate that
calculations under the statutory good time scheme ought not
result in a discharge date that is before the inmate’s parole
eligibility date. We said further that “the intent of habitual
criminal sentencing is thwarted if good time credit is applied
to the maximum term of the sentence before the mandatory
minimum sentence has been served. The minimum portion of
the sentence would have no meaning.”28
   It is unclear from the record whether Johnson predates the
conduct for which Caton is currently serving his sentence.
Regardless, our reading of the good time statutes in Johnson
and Castillas was neither surprising nor legally unsupport-
able. Accordingly, the Department did not violate Caton’s
right to due process when it calculated his mandatory dis-
charge date in accordance with the calculation method set
forth in Castillas.
                        CONCLUSION
   We affirm the district court’s grant of summary judgment in
favor of the State in Caton’s action for habeas corpus relief.
                                                    A ffirmed.
   Heavican, C.J., not participating.

26	
      Id. at 190-91, 826 N.W.2d at 268. See, also, State v. Kinser, 283 Neb. 560,
      811 N.W.2d 227 (2012).
27	
      Johnson v. Kenney, 265 Neb. 47, 654 N.W.2d 191 (2002).
28	
      Id. at 51, 654 N.W.2d at 194.
