 United States Court of Appeals
         FOR THE DISTRICT OF COLUMBIA CIRCUIT



Argued April 7, 2014               Decided September 2, 2014

                        No. 12-5290

                  RONNIE LEROY HOWARD,
                       APPELLANT

                              v.

      CAUFIELD, WARDEN AND UNITED STATES PAROLE
                    COMMISSION,
                     APPELLEES


        Appeal from the United States District Court
                for the District of Columbia
                    (No. 1:09-cv-00211)


    Beverly G. Dyer, Assistant Federal Public Defender,
argued the cause for appellant. With her on the brief was A.J.
Kramer, Federal Public Defender.

    Ronnie Leroy Howard, pro se, filed briefs for appellant.

    Katherine M. Kelly, Assistant U.S. Attorney, argued the
cause for appellees. With her on the brief were Ronald C.
Machen Jr., U.S. Attorney, and Elizabeth Trosman, John P.
Mannarino, and Carolyn K. Kolben, Assistant U.S. Attorneys.
R. Craig Lawrence, Assistant U.S. Attorney, entered an
appearance.
                                2
    Before: ROGERS, GRIFFITH and PILLARD, Circuit Judges.

    Opinion for the Court filed by Circuit Judge PILLARD.

     PILLARD, Circuit Judge: Ronnie Leroy Howard appeals
the denial of his petition for a writ of habeas corpus. Howard
is a federal parolee with an expected parole termination date
of June 5, 2016.1 He seeks immediate release from parole,
contending that procedural irregularities relating to parole
revocations in 1985 and 2004 warrant habeas corpus relief.

      Howard makes three roughly distinct challenges to his
federal parole.      First, he argues that the U.S. Parole
Commission (“Commission”), through a “Notice of Action”
following a 1985 parole revocation hearing, ordered that the
first five years of an intervening state sentence, from 1982 to
1987, would run concurrently with his federal sentence, but

1
   Effective November 1, 1987, the Sentencing Reform Act of
1984, Pub. L. No. 98-473, § 212(a)(2), 98 Stat. 1837, 1999 (1984),
“eliminated most forms of parole in favor of supervised release, a
form of postconfinement monitoring overseen by the sentencing
court, rather than the Parole Commission.” Johnson v. United
States, 529 U.S. 694, 696-97 (2000) (citing Gozlon-Peretz v. United
States, 498 U.S. 395, 400-01 (1991)); see 18 U.S.C. § 3583.
Congress has extended the federal parole system seven times to
allow the Commission to continue monitoring the handful of
individuals, like Howard, who were sentenced for offenses
committed before November 1, 1987, and who remain on federal
parole. See, e.g., United States Parole Commission Extension Act
of 2013, Pub. L. No. 113-47, § 2, 127 Stat. 572 (2013) (extending
parole through 2018). The primary difference between parole and
supervised release is that the latter is an additional, independent
term of supervision imposed at sentencing, whereas parole is
granted to individuals already serving a term of confinement,
allowing them to complete an existing sentence of incarceration
outside of prison.
                              3
failed to treat them as concurrent. But for the Commission’s
failure to run his terms concurrently, as Howard says the
Commission informed him it would, he would now be free
from parole. Howard’s claims arising out of that alleged
surprise reversal fail because they all rest, at bottom, on a
misreading of the admittedly opaque Notice of Action, which
directed that the specified five years would run consecutively.

     Second, Howard makes several arguments founded on his
contention that the Commission did not properly execute, or
never executed, a 1982 parole violator warrant it lodged
against him. At the conclusion of the three day evidentiary
hearing in this case, the magistrate judge found that the
Commission executed the 1982 warrant on July 21, 1987.
Howard argues, however, (1) that the magistrate judge’s
factual finding was clearly erroneous, (2) that the magistrate
judge abused her discretion and violated his due process
rights by failing to aid him in calling additional witnesses at
the evidentiary hearing whose testimony could have helped
him to prove that the Commission did not execute the warrant
in 1987, and (3) that he received ineffective assistance of
counsel because his attorney failed adequately to press his
warrant execution argument and failed adequately to help him
to locate and procure his witnesses. All of Howard’s claims
relating to the execution of his 1982 parole violator warrant
fail, however, because Howard had no right to have the
warrant executed, and the Commission had no obligation to
execute it. It is thus immaterial whether the Commission ever
executed the 1982 parole violator warrant.

    Finally, Howard contends that the Commission executed
a separate 1998 parole violator warrant in 2000 or 2002, but
delayed the associated parole revocation hearing until 2004.
He argues that that multiyear delay between execution and
revocation was unreasonable and prejudicial, and therefore
                              4
violated his due process rights. The magistrate judge found,
however, that the Commission executed the 1998 parole
violator warrant in 2004. Howard’s petition raises no grounds
warranting reversal of that determination, and Howard does
not argue that the minor delay between his 2004 warrant
execution and 2004 revocation hearing violated his right to
due process.

     Because none of Howard’s claims merits habeas relief,
we affirm the judgment of the district court denying his
petition.

                              I.

     Howard is a serial recidivist who has served time in
prison for various federal and state crimes and is currently on
federal parole, with an expected parole termination date in
2016. He is a 67-year-old Vietnam veteran who has struggled
for much of his life with addictions to cocaine and other
drugs. He has kidney disease, which, at the time of his
petition, did not yet require dialysis treatment.

    The concurrent 20- and 25-year federal sentences for
which Howard remains on parole were for two bank robberies
Howard committed in 1970. Howard was imprisoned at the
Lorton Reformatory Adult Services Complex, a federal
penitentiary in Lorton, Virginia, but escaped in the early
1970s by climbing a fence, adding 15 months to his sentence.
Several years later, Howard again gained release on parole,
but a further series of crimes, state sentences of
imprisonment, and corresponding breaks in and violations of
his federal parole had, by 2011, pushed Howard’s parole
termination date from 1996 to 2022. After Howard filed this
case, the Commission reduced Howard’s parole term, giving
him an anticipated release date in 2016.
                              5
     Howard traveled a circuitous path to 20 extra years of
federal penal supervision. After Howard served nine years in
federal prison, the government paroled him in 1979. While he
was on parole, Howard committed serious crimes in Virginia,
including armed robbery. In 1982, the Commission issued a
“parole violator warrant” for Howard for those and other
parole violations. A parole violator warrant is a warrant
issued by the Commission pursuant to its authority to “retake”
parolees who have violated their federal parole and return
them to federal prison—or at least formally to return them to
the custody of the Attorney General. 18 U.S.C. § 4213(a)(2).
The Commission did not immediately execute the warrant and
return Howard to federal prison, however, because by then he
was in state prison pursuant to his 1982 conviction and 18-
year sentence for armed robbery in violation of Virginia law.

     In 1985, while Howard was incarcerated in Virginia, the
Commission conducted a “dispositional revocation hearing”
to determine what effect Howard’s parole violations would
have on completion of his federal sentence. At a dispositional
revocation hearing, or parole revocation hearing, the
Commission may revoke parole and return an individual to
federal prison, id. § 4214(d), and, where a parolee is
convicted of a crime “punishable by a term of imprisonment”
during his release on parole, the Commission may also
determine that his time already spent on parole does not count
toward his underlying sentence, id. § 4210(b)(2); see also 28
C.F.R. § 2.52(c)(2). The Commission is also permitted to toll
a parolee’s federal sentence while he serves a term of
imprisonment for another offense. 18 U.S.C. § 4210(b)(2)
(“[T]he Commission shall determine . . . whether all or any
part of the unexpired term [of the original sentence] being
served at the time of parole shall run concurrently or
consecutively with the sentence imposed for the new
                              6
offense . . . .”); see also Santa v. Tippy, 14 F.3d 157, 158-59
(2d Cir. 1994).

     At Howard’s revocation hearing, the Commission
decided to revoke his parole and not to credit the six years he
had been out on parole toward his federal sentence. The
Commission further determined that Howard, who was still
incarcerated in Virginia, would not resume earning credit
toward his federal sentence until 1987. As the magistrate
judge explained, the decision of the Commission “effectively
tolled his federal sentence by 60 months.” App. at 689.

     The Commission informed Howard of its findings
through a Notice of Action, the disputed meaning and legal
effect of which are central to this appeal. A Notice of Action
is, inter alia, a document that the Commission must provide
to a parolee following a parole revocation proceeding. See,
e.g., 18 U.S.C. § 4214(e); 28 C.F.R. § 2.13(c). As relevant
here, following a parole revocation hearing, the Commission
must “furnish the parolee with a written notice of its
determination.” 18 U.S.C. § 4214(e). Howard’s Notice of
Action following his 1985 parole revocation hearing
attempted to communicate to him that the Commission had
decided to revoke his parole and deny him credit for the six
years he had spent on parole since his release from federal
prison in 1979 (including the time he had already served in
prison in Virginia). The Notice of Action also sought to
inform him that time would again start counting towards his
federal sentence upon his release from Virginia custody into
federal custody or after he spent an additional five years in
state prison. No part of his first five years in Virginia
custody, were he to serve that long, would count toward his
federal sentence.
                                7
     In 1987, with Howard still imprisoned in Virginia, his
federal parole began to run again. The effect of the
Commission’s decision was to move back eight years, from
1996 to 2004, the date of expiration of Howard’s federal
sentence. Because of his various parole revocations and
withdrawals of parole credit, Howard was back at square one
with respect to his remaining 17-year federal sentence.2 It
was as if the sentence had been reset to 1979, when he was
released on parole, and the eight years between then and 1987
never happened.

     In 1992, after Howard served nine years in state prison,
Virginia paroled him, and he remained on parole, not
reincarcerated, pursuant to his federal sentence. In the
ensuing years Howard again violated his federal parole by
committing cocaine-related crimes and other offenses in
violation of Virginia law. In 1998, the Commission issued a
new parole violator warrant for Howard, charging him with
parole violations dating back to 1992, including the cocaine-
related crimes. At the urging of Howard’s federal probation
officer, however, in order to afford Howard an opportunity to
participate in a non-prison-based drug treatment program
through the Veterans Administration, the Commission
ordered the 1998 warrant be held in abeyance and did not
immediately arrest Howard and return him to prison. In 2000,
the Commission—apparently by mistake—issued a second
warrant listing the same charges plus two additional technical
parole violations for Howard’s failure to report a change of
residence and failure to submit required reports. The
Commission withdrew that second warrant in 2001.
Meanwhile, the March 1998 warrant remained in abeyance.

2
  Howard had 17 years remaining on his 26-year term, having
served nine years in federal prison from 1970 to 1979 that, unlike
years served as parole, could not be revoked.
                               8
     In 2002, Virginia arrested, tried, and convicted Howard
of the possession of cocaine with intent to distribute,
sentencing him to two years imprisonment.                Shortly
thereafter, the Commission supplemented its 1998 parole
violator warrant to include the 2002 arrest and ordered that it
be reactivated. The Commission ordered that Howard be
arrested or, if he was already in Virginia custody, that the
warrant be lodged as a “detainer” at the institution where he
was being held. A warrant lodged or placed as a detainer
instructs another jurisdiction that is holding an individual not
to release him until the warrant-issuing jurisdiction has had an
opportunity to take him into custody. Moody v. Daggett, 429
U.S. 78, 80 n.2 (1976).

     Upon Howard’s release from Virginia custody in 2004,
federal officials executed the 1998 warrant and took Howard
into federal custody, incarcerating him at the Albemarle-
Charlottesville Joint Security Complex. The Commission
conducted a parole revocation hearing 127 days later and
found that Howard had violated the conditions of his parole.
As it had in 1987, the Commission reset Howard’s parole
clock, revoking the approximately 17 additional years he had
spent on federal parole since 1987, and assigning him a new
release date in 2021. Subsequent parole violations added to
his sentence, moving his release date to 2022.

     In 2006, Howard, who was no longer incarcerated, began
to seek relief in federal court from his continuing federal
parole. The district court in 2010 construed one of his
complaints as a petition for habeas corpus, directed the
Commission to show cause why the writ should not issue, and
referred the petition to a magistrate judge. Howard’s petition
argued, among other things, that between 1982 and 1987 his
federal and state sentences should have run concurrently, and
                               9
that his 2004 parole revocation hearing was unreasonably and
prejudicially delayed.

     In light of that petition, the Commission reconsidered
Howard’s parole term.           The Commission found that
irregularities associated with the execution of his 1998 parole
violator warrant, along with his illness and advanced age,
justified a reduction in the term. The Commission elected to
credit him with approximately five years toward his parole
termination date, revising it from 2022 to 2016.

    The magistrate judge held a three-day evidentiary hearing
in 2011 and issued a Report and Recommendation denying
Howard’s habeas petition. The district court adopted the
Report and Recommendation. This appeal followed.

                              II.

     In reviewing a district court’s decision to grant or deny a
habeas corpus petition, we review its factual findings for clear
error, see Amadeo v. Zant, 486 U.S. 214, 223 (1988), and its
legal conclusions de novo, see Barhoumi v. Obama, 609 F.3d
416, 423 (D.C. Cir. 2010).

                              A.

     The Commission did not improperly deny Howard credit
towards his federal sentence from 1982 to 1987 when he was
a prisoner in Virginia. Howard pins his argument on
language in the Notice of Action the Commission issued
following his 1985 parole revocation hearing. Appellant Br.
at 15, 21-30. The paragraph—under a heading that states that
at the conclusion of Howard’s hearing “the following action
was ordered” (hereinafter the “order”)—explains:
                                10
    Revoke parole; none of the time spent on parole shall
    be credited. The unexpired portion of your federal
    sentence shall commence upon your release from state
    custody or upon federal reparole to your state
    sentence, whichever comes first. Continue to a
    presumptive parole from the violator term after the
    service of sixty months (July 1, 1987).3

3
  The language of the Notice of Action is almost certainly adapted
directly from the Commission’s Rules and Procedures Manual. The
1984 Manual instructs that Commission orders revoking time and
retroactively denying credit for street time should read:

    Revoke parole; none of the time spent on parole shall be
    credited. The unexpired portion of your federal sentence
    shall commence upon your release from state custody or
    upon federal reparole to your state sentence, whichever
    comes first;

    . . . (Continue for a presumptive) parole from the violator
    term (date).

U.S. Parole Comm’n, U.S. Dep’t of Justice, Rules and Procedures
Manual 168 (1984) (“1984 Manual”) (parentheses in original).
Very similar language appears in the current Rules and Procedures
Manual. See U.S. Parole Comm’n, U.S. Dep’t of Justice, Rules and
Procedures Manual 282 (2010) (“2010 Manual”). Because the
Commission’s guidelines instruct the Commission what to say in its
Notices of Action, these confusing and ungrammatical phrases have
been repeated verbatim in innumerable Notices of Action
nationwide for decades. This lack of clarity is troubling because a
Notice of Action is the document meant to communicate to a
parolee how his sentence has been recalculated and thus how much
more time he must spend in custody—whether in prison or on
parole. The Notice of Action should inform the parolee’s critical
decisions about, for instance, whether to take an appeal. The
government should place a high priority on writing such documents
                                11
All parties agree that the phrase “violator term” refers to
Howard’s underlying federal sentences for which he was
scheduled to serve 26 years. The parties also agree that the
order revoked Howard’s parole and denied him credit for his
three years of street time—time spent free on parole—
between 1979 and 1982.

     The meaning of the remainder of the order is contested.
Howard argues that it “can only be interpreted to impose a
concurrent term from 1982-1987,” i.e. as announcing that his
state sentence and federal parole ran concurrently rather than
consecutively. Appellant Br. at 21 (emphasis added). The
government disagrees, contending that the Notice of Action
“makes clear it will not give [Howard] credit toward his
original federal sentence for all of the time spent in state
prison, and therefore, the sentences were consecutive, not
concurrent.” Appellee Br. at 36-37.

     Howard contends that the district court must be reversed
for legal error because he is entitled to release based on his
interpretation of the Notice of Action. But the district court’s
erroneous interpretation of the Notice of Action matters only
if Howard has some underlying right to relief that turns on
what it says. Howard’s briefing focuses on the Notice of
Action’s convoluted wording, apparently to support a claim
that it violated his rights by failing to give him adequate
notice that his terms ran consecutively. If Howard indeed
received no reasonable notice of the Commission’s decision
and was prejudiced thereby, he might have a due process
claim. See Morrissey v. Brewer, 408 U.S. 471, 489 (1972).
Whatever the precise nature of his claim, however, Howard

in plain English.         One would reasonably expect that the
Commission could draft more plainly the language that it intends be
used to inform uncounseled laypeople in federal custody of matters
vitally affecting their freedom.
                              12
has advanced no ground warranting habeas corpus relief. The
Notice of Action, despite its painful legalese, ordered his
sentences to run consecutively.        Together with his
participation in his 1985 parole revocation hearing and his
receipt in 1987 of other Commission documents reflecting the
consecutive sentence, the Notice of Action adequately
informed Howard of the Commission’s decision to run his
terms consecutively.

    The parties spar over the appropriate level of deference
the Court should afford to the Commission’s interpretation of
the Notice of Action. Howard argues for no deference; the
Government for maximal deference. Appellant Br. at 16-20;
Appellee Br. at 29-32; see also Auer v. Robbins, 519 U.S.
452, 461 (1997). A decision regarding the precise degree of
scrutiny is unnecessary, because, even when we review it
without deference, we find that the Commission’s Notice of
Action makes sufficiently clear that Howard’s Virginia and
federal sentences would run consecutively.

     The second sentence of the order sets the date on which
Howard’s federal sentence would again start to run as one of
two dates, “whichever [came] first”: either (a) his “release
from state custody,” i.e., when Virginia released him from
prison; or (b) “federal reparole.” App. at 83. The date of
Howard’s “federal reparole” is specified by the final sentence,
which provides that Howard would “[c]ontinue to a
presumptive parole from the violator term”—that is, his 26-
year federal sentence—“after the service of sixty months (July
1, 1987).” Id. In other words, even though Howard’s federal
and state sentences were not generally concurrent, the Notice
of Action provided that Howard would become presumptively
entitled to concurrent federal reparole after 60 months,
running the federal clock again even if he were then still in
Virginia custody. Howard remained in Virginia state prison
                              13
until 1992—after July 1, 1987—and therefore the second
alternative “[came] first” and Howard was “reparoled to [his]
state sentence,” so the state sentence started counting as
service of federal parole as of July 1987.

     Howard argues that our reading of the Notice of Action is
too generous, and that the key words, “from the violator
term,” cannot bear the meaning the Commission and the court
ascribe to them. In Howard’s view, the Commission could
not “reparole” him “from” a violator term unless he was in
fact serving time toward that violator term when he was
reparoled “from” it. Thus, the sentence that reads “[c]ontinue
to a presumptive parole from the violator term after the
service of sixty months (July 1, 1987)” implies, in Howard’s
estimation, that the notice of action imposes a concurrent term
from 1982 to 1987. Appellant Br. at 21-22. Howard argues
that the words “from the violator term” are used elsewhere in
the Notice of Action to mean what he says they do. For
example, in the “Reasons/Conditions” section the
Commission explains: “If you are still in state custody as of
the above date [July 1, 1987], you will have a presumptive
parole from the violator term to your state sentence on the
above date.” App. at 83. Again, according to Howard, the
government could not have paroled him “from” his violator
term unless he was already serving it concurrently with his
state sentence. Thus Howard argues that the Notice of Action
states that his federal sentence was to run concurrently with
his Virginia sentence. Howard further contends that the
default presumption should be that federal and state sentences
run concurrently, unless the Commission speaks clearly to the
contrary. Because, in his view, “nowhere did the Commission
explicitly impose a consecutive sentence” in his case, his time
spent in Virginia must be credited toward his federal sentence.
                              14
     We disagree. The language of the “order” section of the
Notice of Action is admittedly confusing. It does not
explicitly say that Howard’s state and federal terms are to run
consecutively. But once we parse it carefully and in context,
we understand the Notice of Action to state the Commission’s
determination that Howard’s terms were to run consecutively.
To read the Notice of Action as Howard suggests ignores the
fair import of its words. The phrase “parole from the violator
term” is not meant to indicate that he would have been
serving the violator term immediately before the
recommencement of parole; instead, “parole from the violator
term” simply identifies the criminal sentence from which, for
the Commission’s purposes, he would be paroled—i.e. that
the parole pertains to the federal sentence of incarceration, or
“violator term.” According to the Notice of Action, Howard
was to be returned to parole “from,” as in originating in or
relating to, his federal violator term.

      This understanding is reinforced by the remainder of the
Notice of Action’s text. On the same page as the disputed
“order”       paragraph,     the    Notice      of    Action’s
“Reasons/Conditions” section explains that, if Howard were
still in state custody as of July 1, 1987, he would “have a
presumptive parole from the violator term to [his] state
sentence” on July 1, 1987. App. at 83. The Notice of Action
also stated that, in circumstances like Howard’s—given the
severity of his parole violations—the “[r]eparole guidelines
indicate a customary range of 48-60 months to be served
before re-release” and that “[a]fter review of all relevant
factors and information presented, a decision outside the
guidelines . . . is not found warranted.”         Id.   Those
explanations of the Notice of Action’s practical consequences
fortify our understanding of the meaning of the document as a
whole.
                               15
     Howard also received a parole certificate in August 1987,
a month after his July 1987 reparole date. The parole
certificate stated that Howard’s parole would extend through
October 1, 2004.         The date on the parole certificate
presupposed that Howard’s state and federal sentences ran
consecutively. Howard received that document but did not
object to it for decades, despite the fact that, according to his
current position, it misstated his parole termination date by
several years. See App. at 677.

     Howard insists that, when a Notice is ambiguous on the
point, the presumption should be that sentences run
concurrently. Yet, when Howard had his parole revocation
hearing in 1985, the Commission’s public guidelines and
regulations, as well as decisions of the Supreme Court and
numerous Federal Courts of Appeals, were clear and
unanimous that the Commission’s policy was to run federal
and state sentences consecutively unless otherwise specified.
See, e.g., Moody, 429 U.S. at 85; Still v. U.S. Marshal, 780
F.2d 848, 855 (10th Cir. 1985) (Logan, J., dissenting); U.S.
Parole Comm’n, U.S. Dep’t of Justice, Rules and Procedures
Manual 119 (1984) (“1984 Manual”). The Commission’s
policy has never wavered, and was its policy at the time of
Howard’s revocation hearing and Notice of Action. 28 C.F.R.
§ 2.47(d)(2) (1984).4 Howard insists that he relied on the
advice of his lawyer in concluding that his terms would run
concurrently. Evid. Hearing Tr. May 11, 2011 a.m., at 15:12-
18. But even if Howard was confused, his confusion was not
objectively reasonable in the circumstances of this case. Even
accepting that the Notice of Action is somewhat unclear
standing alone, there can be little doubt as to its meaning
when it is read together with the other relevant facts and

4
  The policy was renumbered from § 2.47(c) to § 2.47(d)(2)
between 1976 and 1986, and now is codified at § 2.47(e)(2).
                              16
against the background of generally available and directly
relevant legal sources.

     In sum, the actions of the Commission at the time
Howard received his Notice of Action, along with the context
and circumstances in which the Commission issued it,
bolstered the Commission’s message that it never intended his
federal and state sentences to run concurrently. Every
document, memorandum, transcript, certificate, and notice of
any kind issued by the Commission regarding Howard’s
parole—save, arguably, Howard’s Notice of Action—made
clear that Howard’s sentences ran consecutively. Howard
stakes his case on an admittedly awkward phrase in his Notice
of Action. Yet the Commission’s reading of the order’s text
and its further explication of its determination in the
remainder of the Notice combine to defeat his claim that the
Commission ordered his sentences run concurrently.

                              B.

     Howard raises several arguments centered on his
contention that the Commission either did not execute his
1982 parole violator warrant in 1987, or did not execute it
properly. The magistrate judge concluded that “the 1982
warrant was executed, and it was executed on July 21, 1987.”
App. at 687. Howard claims that decision was erroneous.
With respect to the propriety of the warrant’s execution,
Howard argues that the Commission never executed the 1982
warrant because he never received notice of its execution, and
because federal agents never took him into physical
custody—both of which, he argues, are necessary for a parole
violator warrant to be executed.

    Howard also raises several procedural challenges to his
habeas corpus hearing before the magistrate judge, all of
which arise out of his dissatisfaction with the judge’s and his
                             17
own attorney’s treatment of his contentions regarding
execution of his 1982 parole violator warrant. He claims that
the magistrate judge abused her discretion and denied him due
process of law because she did not allow him to call several
witnesses he argues would have been able to help him to
establish that the Commission never executed the 1982
warrant. Howard further asserts that he received ineffective
assistance of counsel at his evidentiary hearing because his
attorney did not do enough to help him to procure those
witnesses or to press his argument that the Commission did
not execute the 1982 warrant.

     Those arguments fail together because they rest on the
faulty premise that it is legally material whether Howard’s
1982 parole violator warrant was ever executed. Neither the
Due Process Clause nor any statute or regulation obligated the
Commission to execute the 1982 warrant, see Moody, 429
U.S. at 87; Donn v. Baer, 828 F.2d 487, 489 (8th Cir. 1987),
and the Commission’s authorizing statute did not require it to
execute the warrant in order to exert jurisdiction over
Howard, see 18 U.S.C. §§ 4213(a), 4214(d); see also Heath v.
U.S. Parole Comm’n, 788 F.2d 85, 91 (2d Cir. 1986).
Howard has not identified nor can we discern a violation of
any right Howard might have that would turn on the execution
of his 1982 parole violator warrant.

     To understand why the nonexecution of the 1982 warrant
was legally innocuous, it may be helpful to review the
interplay between parole violator warrants and parole
revocations.    Such warrants are used by the Parole
Commission to take parolees back into federal custody for
alleged parole violations. When such a warrant is executed,
federal law requires that the parolee receive a prompt parole
revocation hearing to determine what consequences will flow
from the parolee’s alleged violation. See Sutherland v.
                              18
McCall, 709 F.2d 730, 732 (D.C. Cir. 1983). But the inverse
is not the case. Even if there is a revocation hearing, there is
no similar requirement that the outstanding parole violator
warrant to which it relates ever be executed. As the Supreme
Court explained in Moody, “execution of the [parole violator]
warrant and custody under that warrant” are the “operative
event[s] triggering any loss of liberty attendant upon parole
revocation.” 429 U.S. at 87. Thus, “the mere issuance of a
parole violator warrant works no present deprivation of
protected liberty sufficient to invoke due process protection.”
Id. at 85. The “Commission . . . has no constitutional duty to
provide [a parolee] an adversary parole hearing until he is
taken into custody as a parole violator by execution of the
warrant.” Id. at 89. Howard was already in custody in
Virginia.

     This asymmetry explains why Howard received a parole
revocation hearing in this case even though the Commission
may never have executed the parole violator warrant to which
it was ostensibly linked.       Moody established that the
Commission may delay executing a parole violator warrant—
and therefore holding a parole revocation hearing—until the
“expiration of [a] parolee’s intervening sentence.” Id. at 89.
The dissenters in Moody were critical of the Court’s
conclusion that the Commission had “no obligation to go
forward with the revocation hearing until after the parolee has
completed the service of his sentence for [a] second offense”
and could therefore “wait as long as 10 or 20 years” before
holding a hearing. 429 U.S. at 91 (Stevens, J., dissenting).
Perhaps mindful of that perceived unfairness, the Commission
has made it a practice to act earlier to hold revocation
hearings on parole violations that result in an independent
term of imprisonment. See Paroling, Recommitting, and
Supervising Federal Prisoners, 46 Fed. Reg. 35,635, 35,635
(July 10, 1981) (recognizing 1980 change in policy to
                              19
“provid[e] revocation hearing more promptly for persons
incarcerated with new sentences”). At the time of Howard’s
incarceration, the Commission’s regulations advised that such
hearings were to be held within 24 months of an individual’s
incarceration, and that the underlying warrant was to be let to
“stand as a detainer.” Id. at 35,637 (announcing extensions to,
inter alia, 28 C.F.R. § 2.47(b)(1)(i)). But once a pre-
execution parole revocation hearing has been held, as it was
in Howard’s case in 1985, there is no requirement that the
underlying parole violator warrant be executed if it is not
needed for the purpose of arrest or detainer. For this reason,
the policy of the Commission at the time of Howard’s
incarceration in Virginia in the 1980s, as today, is to withdraw
parole violator warrants that are no longer needed, not to
execute them. See 1984 Manual at 123; accord U.S. Parole
Comm’n, U.S. Dep’t of Justice, Rules and Procedures Manual
132 (2010) (“2010 Manual”).

     In Howard’s case, the Commission’s 1985 parole
revocation hearing was of this pre-execution type. It
pertained to the same alleged parole violations that led to the
issuance of his 1982 parole violator warrant. Once the
Commission held the hearing, whether the Commission
executed the parole violator warrant or not no longer
mattered, so long as its actions conformed to its decision in
Howard’s parole revocation hearing. The Commission let
Howard’s parole violator warrant stand as a detainer between
1982 and 1987 because the Commission concluded at his
parole revocation hearing that Howard should serve at least
five years in prison for his parole violations—and if Virginia
released him sooner, for whatever reason, the Commission
wanted to ensure it would be notified so it could incarcerate
him at a federal institution to complete the remainder of his
60 months in prison. But once 60 months passed, the
Commission no longer sought to return Howard to federal
                              20
prison, so execution of the warrant was unnecessary. As of
July 21, 1987, in the eyes of the Commission, Howard was
once again on federal parole whether his warrant was
executed or not.

     The premise of the balance of Howard’s claims relating
to the 1982 parole violator warrant is that, if he could prove
the warrant was not executed or executed improperly, he
would be entitled to habeas corpus relief; the error of that
premise is fatal to the related claims. The magistrate judge
permissibly exercised her lawful discretion in determining
that Howard’s proffered witnesses were irrelevant because
their testimony was directed at an extraneous issue. Howard’s
counsel likewise did not render ineffective assistance.
Whether Howard’s attorney had succeeded in locating the
witnesses or pressing Howard’s warrant-execution
contentions more forcefully, it would not have supported his
habeas petition. See Strickland v. Washington, 466 U.S. 668,
691 (1984) (“An error by counsel, even if professionally
unreasonable, does not warrant setting aside the judgment of a
criminal proceeding if the error had no effect on the
judgment.”).

                              C.

     The Commission did not prejudicially delay Howard’s
2004 parole revocation hearing. Federal law requires that a
revocation hearing be held 90 days after execution of a parole
violator warrant. 18 U.S.C. § 4214(c). The Commission’s
failure to meet the statutory deadline, however, is not grounds
for habeas corpus relief unless the delay is so prejudicial to
the parolee that it violates his due process rights. Sutherland,
709 F.2d at 732; see Morrissey, 408 U.S. at 488-89. In this
Circuit, relief for such a due process violation is granted only
“where a petitioner establishes that the Commission’s delay in
                              21
holding a revocation hearing was both unreasonable and
prejudicial.” Sutherland, 709 F.2d at 732.

     Howard argues that the Commission delayed his 2004
parole revocation hearing by several years because it executed
his 1998 parole violator warrant (or “an invalid duplicate”) in
either 2000 or 2002. In Howard’s view, any such execution
started the parole-revocation hearing clock. Howard argues
that the revocation hearing was thus unlawfully delayed by
two to four years, to his material prejudice. Had his
revocation hearing been promptly convened, Howard argues,
he would have had the opportunity to call additional witnesses
and introduce more mitigating evidence at that hearing, and
therefore the Commission would have been far less likely
retroactively to revoke all of his credit for time spent on
parole between 1987 and 2004.

     The magistrate judge found that the Commission
executed his 1998 parole revocation warrant in 2004, and that
it held his parole revocation hearing 127 days later—37 days
beyond the statutory deadline. In particular, the magistrate
judge determined that the Commission issued a parole
violator warrant in 1998, and then held it in abeyance so that
Howard could participate in a non-prison-based drug
treatment program. App. at 668. The Commission issued a
similar, but not identical, parole violator warrant in 2000 that
it withdrew in 2001 as mistaken and duplicative. Id. at 668-
69. In 2002, the Commission supplemented the 1998 warrant
to reflect crimes Howard committed in 2001 and 2002 and
then lodged the warrant as a detainer. Id. at 669-70. The
Commission executed the 1998 warrant in 2004. Id. at 670.

    In support of his contention that the Commission
executed his 1998 warrant in 2000 or 2002, such that his 2004
revocation hearing was unreasonably delayed by several
                               22
years, Howard claims that the magistrate judge’s Report and
Recommendation failed affirmatively to reject his proffered
evidence of multiple executions of the same warrant, and
thereby left those factual questions open and unresolved. But
the magistrate judge heard and considered Howard’s
arguments and evidence on that issue. Her opinion quotes,
summarizes, and presents Howard’s testimony explaining his
contention that the Commission executed his 1998 parole
violator warrant in either 2000 or 2002. App. at 675
(“Petitioner testified that in February or March, 2001, he
‘[was] released on bond . . . for the local Virginia
charge[] . . . , [and] from the Federal parole warrant[.]’”
(alterations in original)); id. at 676 (“Petitioner testified that
he was arrested in October, 2002 in Arlington County ‘for a
Federal parole violator warrant[,]’ and that the United States
Marshals took him to the jail in Alexandria, then returned him
to Arlington County.” (alterations in original)); see also id. at
676-78 (describing government’s cross-examination focused
on showing that neither warrant execution happened). The
magistrate judge did not fail to address Howard’s evidence,
but considered it and did not credit it.5

    Howard cannot relitigate the magistrate judge’s factual
conclusions regarding his warrant issuances and executions
unless he can show clear error. On questions regarding
“specific factual determinations about what happened” and

5
  The magistrate judge devoted several paragraphs of the Report
and Recommendation to explaining why the Commission’s delay in
executing the 1998 warrant until 2004 did not prejudice Howard.
App. at 689-91. He does not appeal on that ground. That discussion
is relevant here, however, because its factual premise is that the
Commission executed the 1998 warrant in 2004. In failing to find
that an earlier warrant execution occurred, the magistrate judge’s
opinion rejected Howard’s arguments that the Commission
executed the 1998 warrant in either 2000 or 2002.
                              23
judgments about “whether evidence is sufficiently reliable to
credit,” we may reverse the judgment below only if it is
clearly erroneous. Obaydullah v. Obama, 688 F.3d 784, 792
(D.C. Cir. 2012) (internal quotation marks omitted). Howard
identifies evidence pointing both ways on the question
whether the Commission executed the 1998 warrant in 2000
or 2002, see, e.g., Appellant Br. at 40-46, but his analysis of
the record does not leave this Court with a “definite and firm
conviction that a mistake has been committed,” United States
v. U.S. Gypsum Co., 333 U.S. 364, 395 (1948).

     Howard’s habeas claim turns on establishing that the
Commission’s delay of his parole revocation hearing was both
unreasonable and prejudicial. He asserted a lengthy delay of
two to four years and his only claim of prejudice relates to
that longer period. The magistrate judge’s finding that the
Commission executed the warrant in 2004 eliminates
Howard’s claim that the Commission’s delay prejudiced him.
The only delay at issue on these facts is that his hearing was
not held until 127 days after his warrant execution—37 days
beyond the 90-day statutory deadline. Howard does not
contend that that delay during 2004 was unreasonable or
prejudicial; indeed, he disclaims any such prejudice.
Appellant Reply Br. at 15.

    Because the Commission validly executed Howard’s
warrant in 2004, and he has not attempted to show that the
delay thereafter in holding his parole revocation hearing was
unreasonable or prejudicial, we hold that he cannot obtain
habeas relief on that ground.

                            * * *

    For the foregoing reasons, the decision of the district
court is affirmed.
