 United States Court of Appeals
         FOR THE DISTRICT OF COLUMBIA CIRCUIT



Argued February 12, 2015               Decided July 14, 2015

                        No. 13-5177

                        ARI BAILEY,
                        APPELLANT

                             v.

      ISAAC FULWOOD, JR., CHAIRMAN OF U.S. PAROLE
                 COMMISSION, ET AL.,
                      APPELLEES


        Appeal from the United States District Court
                for the District of Columbia
                    (No. 1:12-cv-00498)


    Matthew A. Seligman, appointed by the court, argued the
cause and filed the briefs for appellant.

     Jane M. Lyons, Assistant U.S. Attorney, argued the cause
for appellees. With her on the brief were Ronald C. Machen,
Jr., U.S. Attorney, and R. Craig Lawrence, Assistant U.S.
Attorney.

    Before: HENDERSON, ROGERS and BROWN, Circuit
Judges.

    Opinion for the court filed by Circuit Judge BROWN.
                                    2
    Opinion concurring in part and dissenting in part filed by
Circuit Judge ROGERS.

     BROWN, Circuit Judge: Appellant challenges the United
States Parole Commission’s (USPC) denial of his 2010 and
2012 applications for parole. In particular, he asserts the
USPC violated the Constitution’s prohibition on ex post facto
laws, U.S. CONST. art. I, § 9, cl. 3, by incorrectly applying the
regulations in place at the time of appellant’s underlying
offense. The district court dismissed appellant’s complaint
for failure to state a claim. On review, we find that the
USPC’s denial of appellant’s requests for parole was a valid
exercise of parole authority as it existed at the time of his
offense. In addition, the USPC did not rely on the retroactive
application of any law, regulation, or guideline to justify its
decisions, and therefore could not have violated the Ex Post
Facto Clause. See Fletcher v. District of Columbia (Fletcher
II), 391 F.3d 250, 251 (D.C. Cir. 2004). Accordingly, we
affirm the judgment of the court below.

                                    I.

     Ari Bailey is currently serving a fifteen- to forty-five-year
sentence for a rape he committed in December 1993. In 2004,
after Bailey had served ten years of his sentence, he became
eligible for parole. After an initial parole hearing before the
USPC in September 2004, Bailey was denied parole. In 2007,
2010, and 2012, Bailey again applied for parole. 1 After
rehearings, the USPC denied each of Bailey’s applications.

    Between the time Bailey committed his crime and the time
he became eligible for parole, the law governing parole for
individuals convicted of criminal violations of the D.C. Code

1
    Bailey’s 2007 application for parole is not at issue here.
                               3
underwent several changes. In 1993, at the time of Bailey’s
offense, the D.C. Parole Board (“Board”) made parole
determinations for D.C. offenders. D.C. CODE §§ 24-201.1 –
201.3 (1989), superseded by § 24-131 (2001). The Board
exercised its authority pursuant to section 24-204 of the D.C.
Code, which provided:

    Whenever it shall appear to the Board of Parole that
    there is a reasonable probability that a prisoner will
    live and remain at liberty without violating the law,
    that his release is not incompatible with the welfare of
    society, and that he has served the minimum sentence
    imposed or the prescribed portion of his sentence, as
    the case may be, the Board may authorize his release
    on parole upon such terms and conditions as the
    Board shall from time to time prescribe.

Id. § 24-204(a) (1989), superseded by § 24-404(a) (2009).

     In 1987, the Board promulgated guidelines to govern its
evaluation of a prisoner’s suitability for parole. See D.C.
MUN. REGS. tit. 28, §§ 100, et seq. (1987) (“1987 Guidelines”),
superseded by 28 C.F.R. §§ 2.70, et seq. (“2000 Guidelines”).
The 1987 Guidelines created a point system focused on
offender history, offense characteristics, and behavior while in
prison. The resulting point total determined whether parole
would be granted. Id. § 204.19. However, the Guidelines
also allowed the Board to override the point-based
determination in “unusual circumstances.” Id. § 204.22. See
Daniel v. Fulwood, 766 F.3d 57, 59 (D.C. Cir. 2014). In
1991, in an effort to “facilitate consistency in Guideline
application,” the Board also issued an unpublished policy
guideline that provided definitions of criteria, parameters, and
terms used in the 1987 Guidelines. Policy Guideline, D.C.
Board of Parole (Dec. 16, 1991) (“1991 Policy Guideline”).
                                4
     In 1997, Congress abolished the Board and directed the
USPC to conduct parole hearings for D.C. offenders.
National Capital Revitalization and Self-Government
Improvement Act, Pub. L. No. 105-33, § 11231 (a)–(c), 111
Stat. 712, 745 (1997), codified at D.C. CODE § 24-131 (2001).
Like the Board it replaced, the USPC was given authority to
grant parole “where there is a reasonable probability that a
prisoner will live and remain at liberty without violating the
law, [and where] . . . his or her release is not incompatible with
the welfare of society.” D.C. CODE § 24-404 (2009). In
2000, the USPC promulgated its own parole guidelines, the
2000 Guidelines, which initially applied to all D.C. offenders
who became eligible for parole on or after August 5, 1998. 28
C.F.R. §§ 2.70, et seq.

     In Fletcher v. Reilly (Fletcher III), 433 F.3d 867 (D.C. Cir.
2006), this Court recognized that the 1987 Guidelines and the
2000 Guidelines were “substantially different.” Id. at 877–78.
As a result, the Court warned, retroactive application of the
2000 guidelines could give rise to a violation of the Ex Post
Facto Clause. Id. at 878–79. Subsequently, in Sellmon v.
Reilly, 551 F. Supp. 2d 66 (D.D.C. 2008), the district court
ruled in favor of four prisoner-plaintiffs who argued they
“faced a significantly increased risk of lengthier incarceration
due to the [retroactive application of the] 2000 Guidelines.”
Id. at 91. The district court therefore ordered the USPC to
reevaluate the prisoner-plaintiffs’ parole applications under the
1987 Guidelines. Id. at 99.

     In light of these rulings and others, the USPC promulgated
a new rule—sometimes referred to as the Sellmon Rule—to
address retroactive applications of the 2000 Guidelines. 28
C.F.R. § 2.80(o). Under the Sellmon Rule, the USPC applies
the 1987 Guidelines when reviewing parole applications filed
by a D.C. offender who committed his offense between March
                               5
4, 1985 and August 4, 1998. Id.; see also, e.g., Taylor v.
Reilly, 685 F.3d 1110, 1112 (D.C. Cir. 2012). Accordingly,
the 1987 Guidelines governed appellant’s 2010 and 2012
parole rehearings—the two rehearings at issue in this case.
See March 1, 2010 Notice of Action, J.A. 74; March 19, 2012
Notice of Action, J.A. 79.

    On March 1, 2010, the USPC informed Bailey that his
request for parole was denied. As the Commission explained:

    The Commission has applied the D.C. Board of
    Parole’s 1987 guidelines to . . . your case. You have
    a total point score of 2 under the guidelines for D.C.
    offenders. The guidelines indicate that parole should
    be granted at this time. However, a departure from
    the guidelines at this consideration [sic] is found
    warranted because the Commission finds there is a
    reasonable probability that you would not obey the
    law if released and your release would endanger the
    public safety.

March 1, 2010 Notice of Action, J.A. 74. Specifically, the
Commission provided that its decision was based on the fact
that (1) Bailey had “not completed any programs that address
the underlying cause of [his] criminal conduct of rape;” (2) he
“continued to deny the offense conduct;” (3) he “never
expressed an interest in participating in relevant programming
to address [his] criminal conduct;” (4) in the two prior years he
had “completed no other rehabilitative programs that would
indicate [his] risk to the community has been lessened;” and (5)
he “continued to incur incident reports for threatening and
assaultive conduct.” Id.

    In 2012, after another rehearing, the USPC again denied
appellant parole. March 19, 2012 Notice of Action, J.A. 79.
                               6
As in 2010, the Commission concluded there was “a
reasonable probability [he] would not obey the law if released
and [his] release would endanger public safety.” Id. The
Commission explained its denial was based on the fact that (1)
Bailey had “not completed any programs that address the
underlying cause of [his] criminal conduct of rape;” (2) at the
time he committed rape in DC “there was an outstanding
warrant for [his] arrest on another rape [charge] in Baltimore,
Maryland;” and (3) he had “been confined to a closed prison
setting in the past two years based on [his] prior institution
misconduct” and had not “continued significant programming
since that time.” Id.

     On March 30, 2012, appellant filed a complaint arguing
the 2010 and 2012 parole decisions violated his rights under
the Ex Post Facto Clause. On May 20, 2013, the district court
granted the government’s motion to dismiss after concluding
that “[t]here is no ex post facto violation where, as here, the
USPC applied the regulations that were in effect at the time the
plaintiff committed the underlying criminal offense.” Bailey
v. Fulwood (Bailey I), 945 F. Supp. 2d 62, 63 (D.D.C. 2013).
Thereafter, Bailey filed a timely notice of appeal.

                              II.

     Appellant contends the USPC “violated the Ex Post Facto
Clause of the Constitution . . . by denying Mr. Bailey parole on
the basis of factors that were impermissible under the Board’s
1987 Guidelines and 1991 Policy Guideline but are permissible
under the Commission’s [2000] Guidelines.” Opening Brief
of Court-appointed Amicus Curiae in Support of Appellant at
15. This argument fails in two respects. First, the USPC’s
decisions were a permissible exercise of its statutory
discretion, which was cabined neither by the 1987 Guidelines
nor by the 1991 Policy Guideline. Second, a violation of the
                                7
Ex Post Facto Clause requires retroactive application of a law,
regulation, or guideline. Here, the USPC did not base its
denial on an application of the 2000 Guidelines. Rather, it
explicitly relied on the 1987 Guidelines as the basis for its
actions. Accordingly, the USPC did not violate the Ex Post
Facto Clause.

                               A.

     It is clearly established under D.C. law that the factors set
forth in the 1987 Regulations and the definitions articulated in
the 1991 Policy Guideline never constrained the discretion of
the Board or the USPC. As the D.C. Court of Appeals
explained in McRae v. Hyman, 667 A.2d 1356 (D.C. 1995), our
analysis of this issue must begin with the governing statute, id.
at 1359, which provides that “the Board may authorize [a
prisoner’s] release on parole” if it determines “there is a
reasonable probability that a prisoner will live and remain at
liberty without violating the law . . . [or endangering] the
welfare of society.” D.C. Code § 24-204(a) (1989) (emphasis
added). As the Court observed in McRae, this statute is
phrased “in discretionary terms.” 667 A.2d at 1360. In turn,
the 1987 Guidelines “incorporate this discretionary approach,”
id. at 1359, and set forth a system “to guide the Board in
making the decision whether to grant or deny the parole”—not
to limit it, id. at 1360 (emphasis added). Where the Board
exercises its discretion to depart from this numerical system, it
may do so as long as it “specif[ies] in writing those factors
which it used. Departures must be explained, but they are not
proscribed.” Id. (emphasis added). As the McRae Court
concluded, the Board need not render a decision based on a
strict application of the system set forth in the 1987
Regulations. Rather, it must simply adhere to “the words of
the governing statute, § 24-204(a), [and determine whether a
prisoner is able to] live and remain at liberty without violating
                                  8
the law such that release would be compatible with the welfare
of society.” Id. at 1361; see also id. at 1360–61 (holding the
Board “is not required to either grant or deny parole based
upon the score attained” and it may “ignore the results of the
scoring system and either grant or deny parole in the individual
case” so long as it specifies the reasons in writing).

     The holding in McRae does not stand alone. In two prior
cases, the D.C. Court of Appeals had already explained the
broad discretion retained by the Board under the 1987
Regulations. Davis v. Henderson, 652 A.2d 634 (D.C. 1995);
White v. Hyman, 647 A.2d 1175, 1180 (D.C. 1994) (“[T]he
statute and Regulation vest in the Board substantial discretion
in granting or denying parole.”). In Davis, the Court
compared the Board’s discretion under the 1987 Regulations to
its extensive discretion under the 1980 Regulations prior to the
introduction of the formalized scoring system and concluded
“[t]he discretion conferred by the 1980 guidelines . . . survived
in the 1987 revisions.” 652 A.2d at 635. Read together,
these cases compel the conclusion that the 1987 Guidelines did
not diminish the broad discretion to deny parole afforded to the
Board under section 24-204(a) of the D.C. Code. 2

2
  At oral argument, appellant’s court-appointed amicus argued that,
in a footnote, the McRae Court held that the 1987 Guidelines
constrained the Board’s discretion. McRae, 667 A.2d at 1361 n.15;
Oral Argument at 10:30–11:28. We disagree. The footnote simply
clarifies that where the Board’s denial of parole is a reasonable
exercise of its discretion under the statute, then it is necessarily a
reasonable exercise of its discretion under the 1987 Guidelines. In
the paragraph to which the footnote pertains, the Court explained
that, based on the reasons it set forth, “the Board could readily
determine, in the words of the governing statute, § 24-204(a), that
there was no reasonable probability that McRae would ‘live and
remain at liberty without violating the law’ or that release would be
compatible ‘with the welfare of society.’” Id. at 1361 (emphasis
                                  9
     This conclusion is further bolstered by our own
“independent review of the regulations” in Ellis v. District of
Columbia, which concluded that even section 204.1 of the
1987 Guidelines does not constrain the Board’s discretion. 84
F.3d 1413, 1419 (D.C. Cir. 1996). Section 204.1 provides:
“Any parole release decision falling outside the numerically
determined guideline shall be explained by reference to the
specific aggravating or mitigating factors as stated in
Appendices 2-1 and 2-2.” 1987 Guidelines, § 204.1. Among
the factors listed in “Appendices 2-1 and 2-2” are “Other,” id.
app. 2-1, and “Other change in circumstances,” id., app. 2-2.
As this court explained, the inclusion of such “scarcely
constraining language” suggests that the “Board, in the
exercise of its discretion,” may deny a prisoner parole if it
“believes there is some . . . reason for not granting him parole.”
Ellis, 84 F.3d at 1419; see also id. (“Under § 204.22 of the
[1987 Guidelines], if the Board wished to disregard the results
of the scoring system it merely had to say so in writing.”)
(emphasis added); Phillips v. Fulwood, 616 F.3d 577, 582
(D.C. Cir 2010) (“The 2000 regulations permit the
Commission, in ‘unusual circumstances,’ to depart upward
based on a prisoner’s risk to society. But so too did the 1987
regulations.”). To emphasize the extent of this discretion, we
held that under D.C. law, “parole is never required”—even
where “the Board determines that [a prisoner meets] the
necessary prerequisites” for release. Ellis, 84 F.3d at 1420.
Thus, “a prisoner’s low total point score [under the 1987


added). Then, in the footnote in question, the Court specified, “[f]or
the same reasons we reject McRae’s contention that the denial of
parole was arbitrary and capricious. We also reject McRae’s
contention . . . that the Board violated [the 1987 Guidelines].” Id. at
1361 n.15 (emphasis added). In other words, the Board’s discretion
under the 1987 Guidelines is co-extensive with its discretion under
section 24-204(a).
                                 10
Regulations] does not compel the Board to grant a prisoner
release.” Id.

     To be sure, as Judge Tatel noted in his concurrence in
Ellis, one could read the 1987 Regulations differently. Ellis,
84 F.3d at 1427–28 (Tatel, J., concurring in part).
Specifically, we could interpret the 1987 Guidelines as
constraining the Board’s discretion by requiring it to “apply[] a
set of specified standards” in denying parole to prisoners with
qualifying scores. Id. at 1428. However, as Judge Tatel
ultimately concluded, in light of the rulings of the D.C. Court
of Appeals, we may not adopt such an interpretation. Id. at
1429; see also id. at 1420 (“Although we are not bound by the
D.C. Court of Appeals’s interpretation of the Constitution, we
must respect its construction of D.C. law.”). Accordingly, the
1987 Guidelines did not constrain the Board’s discretion, nor
do they now constrain the USPC’s.

     Similarly, the 1991 Policy Guideline does not limit the
USPC’s discretion. First, though none of the opinions
mentioned expressly discuss the 1991 Policy Guideline, such
an omission is telling. 3 For judges, a significant change to a
legal regime is like an alligator in one’s bathtub; it cannot
prudently be ignored. If the 1991 Policy Guideline had
altered the scope of the Board’s discretion, the judicial
response would not have been silence. Second, in the context
of parole set-offs, the D.C. Court of Appeals has explained
“[t]he [1991 Policy] Guideline[] undoubtedly reflect[s], rather
than limit[s], the discretion that the District’s municipal
regulations and parole statute already vest in the Board’s
set-off determinations.” Hall v. Henderson, 672 A.2d 1047,

3
  White, 647 A.32d at 1178, is an exception in this regard in that it
contains a brief discussion of the 1991 Policy Guideline. However,
its focus is on issues inapposite to the case at bar. Id.
                              11
1053 (D.C. 1996). There is no reason to believe this
conclusion, for which the Court cites both White and McRae as
authority, does not apply with the same force to parole
determinations themselves. Id. at 1054. Finally, it would be
somewhat unusual to deem that the unpublished 1991 Policy
Guideline trumps a statutory enactment or published
regulation. Cf. San Luis Obispo Mothers for Peace v. U.S.
Nuclear Regulatory Comm’n, 789 F.2d 26, 33 (D.C. Cir. 1986)
(“To accept petitioners’ argument, therefore, we would have to
hold that NUREG–0654, a staff document intended as
guidance, supersedes the regulation itself. The only virtue of
that approach is novelty.”); Edward v. D.C. Taxicab Comm’n,
645 A.2d 600, 603 n.10 (D.C. 1994) (“This court has often
applied federal administrative law principles to local
administrative agency proceedings.”).

     Accordingly, we are bound to conclude that the 1987
Guidelines and the 1991 Policy Guideline do not constrain the
discretion of the USPC. Therefore, the USPC did not violate
either of them when it denied Bailey parole after finding “a
reasonable probability that [he] would not obey the law if
released and [that his] release would endanger the public
safety.” March 1, 2010 Notice of Action, J.A. 74; March 19,
2012 Notice of Action, J.A. 79.

                              B.

                               1.

     Even if the USPC had failed in its effort properly to apply
the 1987 Regulations and 1991 Policy Guideline, such a
mistake could not be the basis for a claim under the Ex Post
Facto Clause. Indeed, the government did not rely on the
retroactive application of any statute, regulation, or guideline
to justify its denial of Bailey’s requests for parole.
                              12
     As the Supreme Court explained in Garner v. Jones, 529
U.S. 244 (2000), “the Ex Post Facto Clause . . . bar[s]
enactments which, by retroactive operation, increase the
punishment for a crime after its commission . . . [and]
[r]etroactive changes in laws governing parole or prisoners, in
some instances, may be violative of this precept.” Id. at 249–
50 (emphasis added).           Admittedly, such “[r]etroactive
changes in laws” can include changes to regulations and even
guidelines governing the parole process. Id. at 250, 252; see
also Fletcher II, 391 F.3d at 251 (“The Supreme Court [in
Garner] thus foreclosed our categorical distinction between a
measure with the force of law and guidelines [that] are merely
policy statements from which the Commission may depart in
its discretion.”). However, a necessary feature of any ex post
facto claim is a rule to which the government seeks to give
retroactive effect. See, e.g., Garner, 529 U.S. at 252 (“The
case turns on the [retroactive] operation of the amendment to
Rule 475-3-.05-2.”); Daniel, 766 F.3d at 61 (“In order to
prevail on the merits of an ex post facto claim with regard to
parole guidelines, a plaintiff must show that retroactive
application of new guidelines creates a significant risk of
prolonging his incarceration as compared to application of the
prior guidelines.”); Phillips, 616 F.3d at 578 (“Although he has
been eligible for parole since 2003, the United States Parole
Commission—applying regulations it issued in 2000—has
repeatedly found him unsuitable for release. Phillips contends
that the Commission should have applied the parole rules that
were in effect when he committed his crimes, and that its
failure to do so violated the Ex Post Facto Clause of the
Constitution.”); Fletcher III, 433 F.3d at 876 (“[Fletcher]
contends that the Commission’s retroactive application of the
new federal reparole regulations, rather than the Board’s
regulation, during his 2000 reparole hearing, creates a
significant risk of increased punishment, and is thus an
unconstitutional ex post facto law.”); see also Taylor, 685 F.3d
                             13
at 1112–13 (noting plaintiff did not contest his claim for
injunctive and declaratory relief under the Ex Post Facto
Clause became moot when the USPC agreed to grant him a
new parole hearing and apply the 1987 Guidelines). Here, the
USPC justified its decisions without invoking any retroactive
laws.

                              2.

     Appellant’s court-appointed amicus calls into question
this bedrock principle of Ex Post Facto Clause
jurisprudence—that the clause only applies where the
government seeks to give retroactive effect to a legal rule.
Citing Sellmon, amicus argues that “[d]efendants may not
avoid a constitutional challenge simply by citing the correct
rules, while in fact following a federal practice that is
inapplicable to [Mr. Bailey].”            Opening Brief of
Court-appointed Amicus Curiae in Support of Appellant at 34–
35 (quoting Sellmon, 551 F. Supp. 2d at 96) (second alteration
in original).      According to amicus, “[a]llowing the
Commission to evade the requirements of the Ex Post Facto
Clause merely by asserting that it applied the 1987 Guidelines
while its analysis in practice applied the 2000 Guidelines
would eviscerate the protections afforded by the Clause.” Id.
at 35. However, despite amicus’ arguments to the contrary, as
the district court observed, the Ex Post Facto Clause asks
whether the USPC “applied the correct parole guidelines” and
not whether the USPC correctly applied the parole guidelines.
Bailey I, 945 F. Supp. 2d at 64.

     The Ex Post Facto Clause constrains the government’s
ability to use retroactive legal rules to justify criminal
punishment. Where, as here, a prisoner believes the USPC
has mis-applied a prospective legal rule, the Clause simply
does not apply. Of course, this is not to say the prisoner has
                                  14
no legal recourse to challenge an alleged mis-application of
law. Prisoners have avenues to challenge the unlawful denial
of a request for parole—even where this denial does not violate
the Ex Post Facto Clause. 4 See, e.g., Furnari v. U.S. Parole
Comm’n, 531 F.3d 241, 247–48 (3d Cir. 2008) (holding that in
reviewing a USPC decision to deny parole on a petition for a
writ of habeas corpus, a federal court inquires into “whether
there is a rational basis in the record for the [Parole
Commission’s] conclusions embodied in its statement of
reasons”); see also Doe v. U.S. Parole Comm’n, No. 13-5279,
2015 WL 233404 (D.C. Cir. Jan. 16, 2015) (unpublished per
curiam) (discussing various causes of action an offender may
assert to challenge USPC decisions). In fact, Bailey himself
has already made use of one such avenue by bringing a habeas
action in the Middle District of Pennsylvania. 5 See Bailey v.

4
  In her opinion concurring in part and dissenting in part, our
colleague asks: “Would the majority hold that the Fourth
Amendment does not prohibit unreasonable searches and seizures
that can be challenged under state tort law?” Concurring Op. at 6.
Although the question is rhetorical, we provide the obvious answer:
The Fourth Amendment does prohibit unreasonable searches and
seizures, irrespective of state tort law. Nonetheless, a search that is
reasonable under the Fourth Amendment may violate state statutory
protections. Similarly, here, prisoners have avenues to challenge
the USPC’s mis-applications of prospective legal rules, even though
such actions do not violate the Ex Post Facto Clause.
5
  In his habeas petition, Bailey advanced several legal theories.
One of them relied on the same Ex Post Facto Clause argument he
advances here. The government asserts the present action is
therefore barred on res judicata and collateral estoppel grounds.
However, we need not decide this issue to resolve the case before us
because neither collateral estoppel nor res judicata deprives the
court of subject-matter jurisdiction. See Smalls v. United States,
471 F.3d 186, 189 (D.C. Cir. 2006) (“[T]he defense of res judicata,
or claim preclusion, while having a somewhat jurisdictional
                                 15
Fulwood, Civil No. 3:CV-11-435, 2012 WL 5938302 (M.D.
Pa. Nov. 26, 2012).

     To extend the Ex Post Facto Clause to cases like the one at
bar would be deleterious to the proper functioning of the
criminal justice system. The Clause strikes a careful balance;
it prohibits retroactive application of parole regulations that
“create[] a significant risk of prolonging [an inmate’s]
incarceration,” Garner, 529 U.S. at 251, while preserving for
parole boards some flexibility in the way they exercise their
discretion prospectively. As the Garner Court explained:

    The danger that legislatures might disfavor certain
    persons after the fact is present even in the parole
    context, and the Court has stated that the Ex Post Facto
    Clause guards against such abuse. On the other hand,
    to the extent there inheres in ex post facto doctrine
    some idea of actual or constructive notice to the
    criminal before commission of the offense of the
    penalty for the transgression we can say with some
    assurance that where parole is concerned discretion, by
    its very definition, is subject to changes in the manner
    in which it is informed and then exercised. The idea of
    discretion is that it has the capacity, and the obligation,
    to change and adapt based on experience. New
    insights into the accuracy of predictions about the
    offense and the risk of recidivism consequent upon the


character, does not affect the subject matter jurisdiction of the
district court.”); cf. Nat’l Treasury Emps. Union v. IRS, 765 F.2d
1174, 1176 n.1 (D.C. Cir. 1985) (recognizing that collateral estoppel,
or issue preclusion, is an affirmative defense under Fed. R. Civ. P.
8(c) that is subject to waiver and forfeiture—and therefore holding,
implicitly, that this defense is not an attack on the court’s
subject-matter jurisdiction).
                               16
    offender’s release, along with a complex of other
    factors, will inform parole decisions.

Id. at 253.

     The rule suggested by the district court in Sellmon and
advocated by appellant would subject any change to a parole
board’s exercise of discretion to constitutional inquiry—even
where the change is explicitly made prospective. Any inmate
denied parole could point to a prospective policy that the board
did not rely on in justifying its decision and argue that this
policy violated his right to be free from “[r]etroactive changes
in laws.” Id. at 250. Parole boards would have no choice but
to “freeze in time” their discretion to insulate themselves from
such absurd challenges. Id. at 259 (Scalia, J., concurring). In
essence, courts would deprive parole boards of “the capacity,
and the obligation, to change and adapt based on experience.”
Id. at 253 (majority opinion). We decline to adopt such a rule.

                               3.

     Here, the USPC did not rely on the 2000 Guidelines to
justify its 2010 and 2012 parole decisions. Rather, “[i]t is
apparent from the Court’s review of the record that the USPC
applied the Parole Board’s 1987 Regulations—not the 2000
Guidelines—in 2010 and again in 2012.” Bailey I, 945 F.
Supp. 2d at 63. As the district court aptly noted, “[t]here is no
[Ex Post Facto Clause] violation where, as here, the USPC
applied the regulations which were in effect at the time the
plaintiff committed the underlying criminal offense.” Id.

    Accordingly, the judgment of the court below is

                                                       Affirmed.
     ROGERS, Circuit Judge, concurring in part and dissenting in
part. This appeal and a related appeal1 arise as a result of
Congress’s transfer of parole responsibilities from the D.C.
Board of Parole to the U.S. Parole Commission in 1998. See
National Capital Revitalization and Self-Government
Improvement Act, Pub. L. No. 105-33, § 11231(a)–(c), 111 Stat.
712, 745 (1997), codified at D.C. Code § 24-131. These
plaintiffs, who sued under 42 U.S.C. § 1983, were convicted
when the D.C. Board was still in charge of parole decisions and
they contend on appeal that the U.S. Commission is carrying out
stricter parole practices than did the D.C. Board. Bailey
contends, adopting the brief of amicus curiae, that the U.S.
Commission violated the Ex Post Facto Clause of the Fifth
Amendment to the Constitution by denying him parole based on
factors that were impermissible under the D.C. Board’s policy
in place at the time of his offense, but permissible under the U.S.
Commission’s subsequent policy.              Because the U.S.
Commission properly applied the D.C. Board’s earlier policy, I
concur in holding that Bailey’s ex post facto challenge fails.
Because that holding disposes of the issue Bailey has presented,
I dissent from the court’s alternative analysis prematurely
announcing a broader ex post facto principle for future cases.

                                     I.

    In interpreting the authority of the D.C. Board of Parole, the
District of Columbia Court of Appeals has held that when acting
pursuant to the 1987 Regulations, the Board retains discretion
under D.C. Code § 24-204(a) to depart from numerical
recommendations set forth in the regulations. See McRae v.
Hyman, 667 A.2d 1356, 1359–61 (D.C. 1995); Davis v.
Henderson, 652 A.2d 634, 635–38 (D.C. 1995); White v.
Hyman, 647 A.2d 1175, 1180 (D.C. 1994). This court has
adopted the D.C. Court of Appeals’s interpretation of D.C. Code

         1
             Gambrell, et al. v. Fulwood, No. 13-5239 (D.C. Cir. July 14,
2015).
                                2

§ 24-204(a) and the parole system established in the D.C.
regulations. See Phillips v. Fulwood, 616 F.3d 577, 582 (D.C.
Cir. 2010); Ellis v. Dist. of Columbia, 84 F.3d 1413, 1420 (D.C.
Cir. 1996). Although the cited D.C. cases either do not discuss
the Board’s 1991 Guideline or do so as to other issues, the
Guideline merely provided definitions for certain terms in the
1987 Regulations and did not purport to limit the D.C. Board’s
discretion under the 1987 Regulations.

     Therefore, essentially for the reasons stated by the court, I
join the court in holding that because “the [U.S. Commission]’s
decisions were a permissible exercise of its statutory discretion,
which was cabined neither by the 1987 Guidelines nor by the
1991 Policy Guideline,” Op. 6–7, Bailey’s ex post facto
challenge fails.

                               II.

     The court insists on going further, concluding alternatively
that a prisoner can never present a claim under the Ex Post
Facto Clause where a parole agency cites the correct regulation
or guidelines. See Op. 7, 11–16. The court normally “do[es] not
reach out to decide” constitutional issues when the appeal does
not require it. Pub. Citizen Health Research Grp. v. Tyson, 796
F.2d 1479, 1507 (D.C. Cir. 1986). The court’s reason for doing
so today is to express its view that Sellmon v. Reilly, 551 F.
Supp. 2d 66, 96 (D.D.C. 2008), misstates the law. Op. 13, 16.
In Sellmon, the district court was “unpersuaded that the
[Commission’s] reference to the 1987 Regulations, standing
alone, is sufficient to bar an ex post facto challenge.” 551 F.
Supp.2d at 96 (emphasis added). This court’s categorical
rejection of Sellmon goes far beyond the facts of Bailey’s case.
In denying parole, the Commission did not simply reference the
1987 Regulations, it correctly applied them. That conclusion
fully resolves the issue Bailey has presented in this appeal.
                                 3

     The court’s alternative conclusion is troubling for two
reasons. First, it may not be correct, and the factual record and
briefing in this case did not focus on the issue so as to allow for
careful consideration. Second, the policy considerations on
which the court relies are dubious at best. The more prudent
course would be to leave consideration of this issue for a case
that actually presented it.

     1. The Ex Post Facto Clause prohibits the passing of an “ex
post facto Law.” U.S. CONST. art. I, § 9, cl. 3. In the parole
context, this prohibition applies to new regulations and policy
guidelines that “create[] a significant risk of prolonging [an
inmate’s] incarceration.” Garner v. Jones, 529 U.S. 244, 251
(2000); see Phillips, 616 F.3d at 580. The analysis involves two
questions: did the parole agency apply a retroactive policy (the
retroactivity question), and, if so, did the retroactive application
carry a significant risk of increased punishment (the risk
question). Answering the retroactivity question will generally
be easy when the parole agency states that it is applying a later
policy. In such cases, the court will only have to answer the risk
question, which requires the court to conduct “a searching
comparison of the old and new” policies to determine whether
application of the later policy “create[s] a significant risk” of
lengthier incarceration. Fletcher v. Reilly, 433 F.3d 867, 879
(D.C. Cir. 2006) (“Fletcher III”). The court’s alternative
analysis speaks to the opposite situation, in which the parole
agency denies parole using an analysis available under the new
policy but not the old (thereby demonstrating a “significant risk”
that applying the new policy will prolong incarceration) but
claims to be applying the prospective policy only. That situation
requires the court to answer the first question: which policy did
the parole agency, in fact, apply?

     In addressing the risk question, the Supreme Court’s ex post
facto precedent has eschewed formalism. It has instructed
                                 4

courts to look at an agency’s “policy statements, along with the
[agency’s] actual practices,” to determine “the manner in which
it is exercising its discretion” under both policies, looking to
“evidence drawn from the rule’s practical implementation.”
Garner, 529 U.S. at 256; see id. at 255. “The controlling inquiry
under Garner is how the Board or the Commission exercises
discretion in practice, and whether differences between the
exercise of discretion in [the] two systems actually” create a
significant risk of increased punishment. Fletcher III, 443 F.3d
at 876–77. “[T]he question is one of practical effect,” not labels.
Fletcher v. Dist. of Columbia, 391 F.3d 250, 251 (D.C. Cir.
2004) (“Fletcher II”). Thus, even if a later policy is facially
similar to the one in place at the time of offense, courts are to
scrutinize whether, in practice, the later policy reflects a stricter
implementation of statutory discretion. In Bailey’s case, the
court has effectively answered that question in the negative,
holding that, as exercised, the discretion is the same under both,
and consequently there is no difference in the risk of punishment
under the two regimes. See also Phillips, 616 F.3d at 582–83.

     The court proceeds to answer the retroactivity question as
well. With virtually no analysis of the Ex Post Facto Clause
itself, the court opines that the parole agency’s characterization
of its action is conclusive on the question of which policy was,
in fact, applied. Thus, in the language of Sellmon, a simple
“reference” to the correct policy, “standing alone,” is sufficient
to bar an[y] ex post facto challenge. 551 F. Supp. 2d at 96
(emphasis added). But if, as the Supreme Court has instructed,
the risk question must take account of actual practice, then it is
not clear why the retroactivity question categorically may not.
The Ex Post Facto Clause prohibits “[e]very law that changes
the punishment, and inflicts a greater punishment, than the law
annexed to the crime, when committed.” Calder v. Bull, 3 U.S.
(3 Dall.) 386, 390 (1798) (Chase, C.J.); see Garner, 529 U.S. at
249–50. It “forbids the imposition of punishment more severe
                                5

than the punishment assigned by law when the act to be
punished occurred.” Weaver v. Graham, 450 U.S. 24, 30 (1981)
(emphasis added). When a parole agency prolongs incarceration
using policy considerations that were not adopted until after the
offense, it contravenes that prohibition regardless of the label it
affixes to its decision. As the Supreme Court has explained, the
Clause “safeguards a fundamental 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.” Peugh v. United States, 133 S. Ct. 2072, 2085
(2013) (quotation marks and alterations omitted). That purpose
is not satisfied by a bare disavowal of any ex post facto
violation.

      Imagine a sentencing judge who considers aggravating
factors enacted after the defendant’s offense, but concludes by
stating “I applied the earlier sentencing law.” Or imagine a
parole agency that changes the factors it will consider from
A,B,C to X,Y,Z, then denies parole based only on the latter set
of factors, but states that it applied the earlier policy. In those
situations, it is unclear why mere averral of compliance with the
Ex Post Facto Clause should override clear facts of the case to
the contrary. The Clause “deals with substance, not shadows.
Its inhibition was levelled at the thing, not the name. It intended
that the rights of the citizen should be secure against deprivation
for past conduct by legislative enactment, under any form,
however disguised.” Weaver, 450 U.S. at 31 n.15 (quoting
Cummings v. Missouri, 71 U.S. (4 Wall.) 277, 325 (1866)). If
the risk question requires an examination of “actual practices”
and “practical effect,” why should the retroactivity question be
blind to practical realities altogether? The court provides no
answer. With no need to reach the question, the court relegates
a core constitutional protection to an easily evaded formalism.

    Granted, not every misapplication of a parole policy
                                6

constitutes an ex post facto violation. Plaintiffs in the
companion case, supra note 1, maintained that the improper
application of a permissible factor amounted to an “unwritten”
policy change, and thereby violated the Ex Post Facto Clause.
An incorrect application of a prospective policy is not
necessarily an ex post facto violation. But neither is the
prospective policy necessarily the one that was applied, for
purposes of the Clause, merely because of a statement to that
effect by the parole agency. In some cases (and again, neither
Bailey’s case nor the companion case require this court to decide
which ones), the facts may be sufficiently clear to establish that
a later rule was applied, despite an agency’s contrary statement.

     2. How, then, does the court reach its conclusion that a bare
assertion cures any possible ex post facto violation? Two policy
reasons. First, the court suggests that the Clause is an
unnecessary prophylactic because prisoners have other “avenues
to challenge the unlawful denial of a request for parole.” Op.
14. The availability of other legal theories or causes of action is
irrelevant to the meaning of the Ex Post Facto Clause. The
Clause exists to prevent retroactive punishment, period. See
Peugh, 133 S. Ct. at 2081 (quoting Calder, 3 U.S. (3 Dall.) at
390). It does not exist merely to prevent retroactive punishment
that is not prevented by other means. Would the majority hold
that the Fourth Amendment does not prohibit unreasonable
searches and seizures that can be challenged under state tort
law? Moreover, the court’s premise may be wrong, as the
court’s citations cast doubt on the availability of other remedies.
See Op. 14 (citing Doe v. U.S. Parole Comm’n, No. 13-5279,
2015 WL 233404 (D.C. Cir. Jan. 16, 2015), where the court
highlights the barriers to bringing a direct appeal, federal
habeas, state habeas, and claims under 42 U.S.C. § 1983 and the
Administrative Procedure Act). Even if other legal theories are
available, the scope of relief may depend on whether or not a
claim is constitutional. See, e.g., 42 U.S.C. §§ 1983, 1988(b).
                                 7

     Second, the court is concerned that enforcing the Ex Post
Facto Clause despite absolving boilerplate might “freeze in
time” the Board’s discretion. Op. 16 (quoting Garner, 529 U.S.
at 259 (Scalia, J., concurring in part in the judgment)). It is not
clear what this means here. Surely the court does not mean to
suggest that a parole agency is free to apply a later policy when
doing so significantly increases the risk of incarceration. The
Supreme Court and this court have held that parole agencies
cannot retroactively apply stricter regulations or guidelines, even
when their statutory discretion is unchanged. See Peugh, 133 S.
Ct. at 2081, 2086; Garner, 529 U.S. at 253–55; Phillips, 616
F.3d at 580; Fletcher III, 433 F.3d at 876–77; Fletcher II, 391
F.3d at 251. In fact, the “freezing” concern comes from a
separate opinion criticizing that conclusion in Garner, see
Garner, 529 U.S. at 257–59 (Scalia, J., concurring in part in the
judgment); but as the court acknowledges, see Op. 12, that
bridge has been crossed. Perhaps the court’s “freezing” concern
is targeted at the “unwritten” policy theory advanced in the
companion case. But rejecting that theory does not require the
court’s broad alternative analysis. Where a parole agency
applies a later policy retrospectively, no concern for “freezing”
the agency’s discretion can overcome the Supreme Court’s
holding in Garner and our cases applying it.

     The court has no reason to make new ex post facto law on
such a weak foundation. As a result of our holding that the D.C.
1987 Regulations and 1991 Guideline do not constrain the U.S.
Commission’s discretion, no prisoner could reasonably
anticipate success in filing an action like Bailey’s because it will
be clear that the U.S. Commission’s exercise of reasoned
discretion is not constrained under the earlier D.C. policy.
                                8

     The court’s alternative analysis thus bears all the worst
hallmarks of an advisory opinion. See United States v.
Fruehauf, 365 U.S. 146, 157 (1961); Alabama State Fed’n of
Labor v. McAdory, 325 U.S. 450, 461–62 (1945) (collecting
cases). Lacking the focus that an actual controversy presents,
the court adopts an ill-considered position with implications well
beyond the facts of Bailey’s case and possibly beyond the parole
context altogether. The parties have barely briefed this issue,
instead treating the ex post facto question as turning on whether
the factors on which the U.S. Commission relied were
permissible under the D.C. Parole Board’s 1987 Regulations and
1991 Guideline. See McBride v. Merrell Dow & Pharm., Inc.,
800 F.2d 1208, 1211 (D.C. Cir. 1986). The court answered that
question in the affirmative, and I concur. Because the court’s
alternative analysis is unnecessary (and unpersuasive), I
respectfully dissent from Part II.B of the court’s opinion (and
the sentences introducing it on page 7) and would leave the
operation of the retroactivity question for another day.
