 United States Court of Appeals
         FOR THE DISTRICT OF COLUMBIA CIRCUIT



Argued October 25, 2019                Decided May 29, 2020

                        No. 18-5350

                  DUANE JOSEPH JOHNSON,
                       APPELLANT

                              v.

                  E. D. WILSON, WARDEN,
                         APPELLEE


        Appeal from the United States District Court
                for the District of Columbia
                    (No. 1:10-cv-00178)


     Amanda J. Sterling argued the cause for appellant. On the
briefs were Alex Young K. Oh and Michelle Parikh.

    Sharon A. Sprague, Assistant U.S. Attorney, argued the
cause for appellee. With her on the brief were Jessie K. Liu,
U.S. Attorney, and Elizabeth Trosman and Chrisellen R. Kolb,
Assistant U.S. Attorneys. Lauren R. Bates and R. Craig
Lawrence, Assistant U.S. Attorneys, entered appearances.

   Before: MILLETT and KATSAS, Circuit Judges, and
SENTELLE, Senior Circuit Judge.

    Opinion for the Court filed by Circuit Judge KATSAS.
                               2
     KATSAS, Circuit Judge: In this federal habeas action,
Duane Johnson contends that he received ineffective assistance
of counsel during the direct appeal of his murder conviction in
D.C. Superior Court. Among other things, Johnson argues that
his appellate counsel labored under two conflicts of interest and
failed to argue that the government withheld exculpatory
evidence. We reject all of Johnson’s contentions.

                                I

                               A

    Around 4 a.m. on April 26, 1994, Keith Nash was shot
twice and killed. His sister, Sharon Nash, was shot once but
survived. Duane Johnson, who was then in a parked car with
the Nashes and three other people, was charged with murder
and other offenses in the Superior Court of the District of
Columbia. At trial, the prosecution and the defense told
conflicting stories about Johnson’s role in the shootings.

     According to the prosecution, Johnson shot the Nashes as
part of an attempted robbery. That evening, Keith, Sharon,
Victor Williams, and LaTina Gary piled into Keith’s sedan and
went out looking for cocaine. The group tried to buy from
Johnson, who had previously supplied Williams, but his price
was too high. Johnson, who was with Damitra Rowel,
nonetheless asked for a ride. Keith agreed, and the pair
crammed into the back seat of his car. At that time, Keith was
driving, Sharon was seated in the front passenger seat, and the
four others were in the back seat, with Johnson at the far left
and Williams at the far right. When they reached an alley,
Johnson ordered Keith to shut off the engine, put a gun to his
head, and demanded money. When Keith refused, Johnson
fired three shots, hitting Keith twice in the neck and Sharon
once in her left side. Johnson and Rowel ran away. Williams
                               3
grabbed Keith’s gun and fired shots after Johnson.         Then
Williams and Gary called 911 to report the shootings.

     In Johnson’s rendition, Keith and Sharon were shot
accidentally as Johnson resisted Williams’s attempt to rob him.
Williams asked Johnson to get in the car to go make a drug sale
to nearby buyers. Skeptical, the unarmed Johnson asked Rowel
to come with him. Keith drove to the alley and turned off the
engine. Then Williams pulled a gun on Johnson and tried to
rob him. Johnson tussled with Williams, whose gun went off
several times. Johnson and Rowel escaped from the car and
ran away, with Williams firing after Johnson.

    The jury believed the prosecution. It found Johnson guilty
of first-degree felony murder while armed, second-degree
murder while armed, and various lesser charges. The Superior
Court sentenced Johnson to 51 years to life in prison.

     At trial and on direct appeal, Johnson was represented by
appointed counsel Frederick Sullivan. On appeal, Sullivan
argued that the evidence was insufficient to convict Johnson
and that the Superior Court had erred by not instructing the jury
on manslaughter. The D.C. Court of Appeals rejected both
arguments but remanded for vacatur of the duplicative counts
of conviction. On remand, the Superior Court resentenced
Johnson to 46 years to life in prison.

                               B

     Since his resentencing, Johnson has raised various
collateral attacks on his conviction. Convictions in the D.C.
Superior Court are subject to a unique regime of collateral
review. A prisoner in custody under a Superior Court sentence
“may move the court to vacate, set aside, or correct the
sentence.” D.C. Code § 23-110(a). To the extent this remedy
is available, it is exclusive. See id. § 23-110(g). Thus, federal
                                4
courts cannot consider habeas petitions filed by prisoners who
have adequate and effective section 23-110 remedies available
to them. See Blair-Bey v. Quick, 151 F.3d 1036, 1042 (D.C.
Cir. 1998). From 1998 to 2006, Johnson filed four section 23-
110 motions, variously alleging ineffective assistance of
counsel and violations of Brady v. Maryland, 373 U.S. 83
(1963). His first three motions were denied or withdrawn.

     In 2007, Johnson discovered that Sullivan, between 1985
and 1987, had represented Williams on charges of first-degree
burglary and armed robbery. Williams had testified for the
prosecution at Johnson’s trial. Johnson moved to amend his
fourth section 23-110 motion to allege that Sullivan had
provided ineffective assistance at trial while laboring under a
conflict of interest from his prior representation of Williams.
Johnson also sought to raise a claim that Sullivan had provided
ineffective assistance in his direct appeal while laboring under
the same conflict. In the D.C. court system, a prisoner can raise
claims for ineffective assistance of appellate counsel only
through a motion to the D.C. Court of Appeals to recall its
mandate, not through a motion to the Superior Court under
section 23-110. See Watson v. United States, 536 A.2d 1056,
1060 (D.C. 1987) (en banc). Johnson claimed ineffective
assistance of appellate counsel in a motion to recall the Court
of Appeals’ mandate. The Court of Appeals denied the motion
without prejudice to the Superior Court’s consideration of
conflict issues in the pending section 23-110 motion.

     In 2008, the D.C. Superior Court rejected Johnson’s claims
of ineffective trial counsel and Brady violations. Johnson
appealed. He also filed another motion to recall the D.C. Court
of Appeals’ mandate. The Court of Appeals denied the motion
on the ground that the conflict issue was already before it in the
appeal from the Superior Court’s decision. A few months later,
                              5
the Court of Appeals affirmed that decision but did not mention
Johnson’s claim of ineffective assistance of appellate counsel.

     In 2010, Johnson filed a federal habeas action under 28
U.S.C. § 2254. The district court held that D.C. Code § 23-
110(g) barred review of all claims other than ineffective
assistance of appellate counsel. It further held that Johnson
was barred from claiming ineffective assistance of appellate
counsel because he had neither moved to recall the mandate nor
claimed that doing so would have failed to protect his rights.
Johnson v. Stansberry, No. 10-cv-178, 2010 WL 358521
(D.D.C. Jan. 29, 2010). We reversed that determination
because Johnson had, in fact, moved to recall the mandate.
Johnson v. Stansberry, No. 10-5346 (D.C. Cir. May 11, 2011).
After further skirmishing, Johnson v. Stansberry, No. 10-cv-
178 (D.D.C. June 30, 2011); Johnson v. Wilson, No. 10-5346
(D.C. Cir. Jan. 2, 2013), the district court referred to a
magistrate judge the claim that Johnson’s appellate counsel had
been ineffective.

     At an evidentiary hearing, the magistrate judge heard
testimony from both Johnson and Sullivan. The magistrate
judge credited Sullivan’s testimony that, when Sullivan
represented Johnson, he had forgotten his prior representation
of Williams. The magistrate judge concluded that Sullivan had
not been ineffective in the appeal, and he recommended
rejecting Johnson’s claim. The district court adopted the
recommendation, denied the habeas petition, and issued a
certificate of appealability. Johnson v. Wilson, No. 10-cv-178,
2018 WL 5297811 (D.D.C. Oct. 25, 2018); Minute Order,
Johnson v. Wilson, No. 10-cv-178 (D.D.C. Dec. 4, 2018).

    In 2020, while this appeal was pending, Johnson moved in
Superior Court for a reduction of his sentence under D.C. Code
§ 24-403.03, which applies to certain sentences for crimes
                               6
committed by minors. The Superior Court granted Johnson’s
motion and ordered him released from custody. United States
v. Johnson, No. 1994 FEL 004696 (D.C. Super. Ct. Feb. 7,
2020). Because Johnson remains on probation and subject to
registration requirements because of his conviction, this appeal
is not moot. See Spencer v. Kemna, 523 U.S. 1, 7 (1998).

                               II

                               A

    Under 28 U.S.C. § 2254(a), a person in custody under the
judgment of a D.C. court may petition for a writ of habeas
corpus on the ground that he is being held “in violation of the
Constitution or laws or treaties of the United States.” Id.; see
Waters v. Lockett, 896 F.3d 559, 566 (D.C. Cir. 2018).
Johnson’s petition alleges that he was held in violation of his
Sixth Amendment right to the effective assistance of appellate
counsel.

     Johnson raises two theories. First, under Cuyler v.
Sullivan, 446 U.S. 335 (1980), he contends that Sullivan’s
performance on appeal was adversely affected by two conflicts
of interest. Second, under Strickland v. Washington, 466 U.S.
668 (1984), Johnson argues that Sullivan was ineffective on
appeal based on his failure to raise Brady claims and his failure
to argue that he had been ineffective at trial.

     In habeas appeals, we review the district court’s legal
determinations de novo and its factual findings for clear error.
See Waters, 896 F.3d at 566. It is unclear whether the Superior
Court or the D.C. Court of Appeals resolved the claims before
us on the merits, which would trigger deferential review of
their decisions. See 28 U.S.C. § 2254(d). We may assume that
                               7
this rule of deference does not apply here, because Johnson’s
claims fail even without it.

                               B

     We begin with Johnson’s Cuyler claims. The Sixth
Amendment provides that “[i]n all criminal prosecutions, the
accused shall enjoy the right … to have the Assistance of
Counsel for his defence.” It encompasses the right to “effective
assistance of counsel,” McMann v. Richardson, 397 U.S. 759,
771 n.14 (1970), both at trial and in a first direct appeal as of
right, see Evitts v. Lucey, 469 U.S. 387, 396 (1985).

     In general, a defendant claiming ineffective assistance
must prove both that his lawyer performed deficiently and that
he suffered prejudice as a result. Strickland, 466 U.S. at 687.
But when a defendant establishes that his counsel was
burdened with an “actual conflict” of interest, prejudice is
presumed, United States v. Gantt, 140 F.3d 249, 254 (D.C. Cir.
1998), and the defendant need only show that the conflict
“adversely affected his lawyer’s performance,” Cuyler, 446
U.S. at 348. An “actual conflict” means that the attorney
“actively represented conflicting interests.” Id. at 350. If the
attorney does not know about the conflict of interest, there can
be no actual conflict. See United States v. McGill, 815 F.3d
846, 943 (D.C. Cir. 2016) (per curiam).

    Johnson argues that two different conflicts of interest
impaired Sullivan’s performance in the appeal. The first
conflict arose from Sullivan’s prior representation of
Williams.1 The second arose from Sullivan’s own self-interest

1
  Neither the Supreme Court nor our Court has decided whether
Cuyler applies to successive as opposed to concurrent
                                8
in not arguing that he had been ineffective at trial. Both
arguments fall short.

                                1

    Johnson’s first Cuyler claim founders because Sullivan
had forgotten his prior representation of Williams and thus
lacked an actual conflict. The district court found that Sullivan,
while representing Johnson, did not remember that he had
represented Williams years earlier. We review that finding
only for clear error, bearing in mind that a finding based on the
credibility of coherent, internally consistent, and facially
plausible witness testimony that is not contradicted by extrinsic
evidence “can virtually never be clear error.” Anderson v.
Bessemer City, 470 U.S. 564, 575 (1985). Here, the district
court’s credibility finding was well supported.2

     At the evidentiary hearing, Sullivan presented a coherent
and believable account of his state of mind while representing
Johnson. From 1985 to 1987, Sullivan represented Williams,
who was charged with first-degree burglary and pleaded guilty
to second-degree theft and unlawful entry. Sullivan testified
that at no time during his representation of Johnson, from 1994
to 1996, did he remember that he previously had represented
Williams. Sullivan explained that he had no system in place to
run conflicts checks and, in particular, to make sure that he had
not previously represented government witnesses. And

representations. See Mickens v. Taylor, 535 U.S. 162, 176 (2002);
United States v. Wright, 745 F.3d 1231, 1233 (D.C. Cir. 2014).
Because Johnson loses either way, we need not decide that issue.
2
   In ruling on Johnson’s claim for ineffective assistance of trial
counsel, the Superior Court did not determine whether Sullivan
remembered having represented Williams. Consequently, we review
only the district court’s findings of fact.
                               9
Sullivan repeatedly testified that he did not recognize Williams
at Johnson’s trial. According to Sullivan, he did not recall his
past representation of Williams until Johnson filed a bar
complaint against him in 2007.

     Sullivan’s testimony was definitive, consistent, and
plausible given the seven years and hundreds of cases that
passed between his representations of Williams and Johnson.
To be sure, Sullivan’s failure to have and to use a reliable
system for vetting potential conflicts was hardly ideal. But the
only question in this appeal is one of fact concerning Sullivan’s
awareness of the conflict. In crediting Sullivan’s testimony,
the district court did not clearly err.

     Johnson offers two main responses, but neither persuades.
First, Johnson argues that Sullivan must have learned about the
prior representation because he used an investigator to find
government witnesses and generally ran public-record searches
on them. But Sullivan testified that, in this case, his
investigator had been unable to find Williams and that he
conducted no background search after receiving from the
government material detailing Williams’s past criminal
history. Second, Johnson notes that Sullivan apparently
believed that he would have to disclose any conflict of interest
to the government, not to Johnson. But even if Sullivan
misunderstood the governing rules, he made no disclosure at
all, which reinforces the district court’s finding that he was
unaware of the conflict.

     The district court did not clearly err in finding that
Sullivan, while representing Johnson, had forgotten his prior
representation of Williams. Because an unknown conflict is
not an actual conflict, Johnson’s first Cuyler claim fails.
                                10
                                 2

     Johnson’s second Cuyler claim arises from Sullivan’s
allegedly conflicting loyalty to Johnson and to himself.
According to Johnson, Sullivan should have argued on appeal
his own ineffectiveness at trial. And given the supposed
conflict of interest, Sullivan’s failure to make the argument
should be analyzed under Cuyler rather than Strickland.

      We conclude that there was no conflict, so we need not
decide whether the kind of first-person conflict alleged by
Johnson, if it existed, would trigger Cuyler. The district court
credited Sullivan’s testimony that, while handling the direct
appeal, Sullivan did not believe that he had been ineffective at
trial. This finding was not clearly erroneous—particularly
because, as explained below, Sullivan’s representation at trial
was not constitutionally ineffective. And because Sullivan did
not believe that he had been ineffective, he had no conflict with
Johnson. Johnson’s second Cuyler claim thus fares no better
than his first.

                                 C

     We turn now to Strickland. Johnson argues that, even
assuming no conflicts, Sullivan still provided ineffective
appellate assistance. To establish this claim, Johnson must
show that Sullivan performed deficiently and thereby
prejudiced the appeal. Strickland, 466 U.S. at 687. A counsel’s
performance is deficient if it “fell below an objective standard
of reasonableness,” id. at 688, and prejudicial if there is at least
a “reasonable probability” that it affected the outcome of the
proceeding, id. at 694.

     We have noted that “when it comes to ineffective-
assistance claims leveled against appellate counsel, there is not
                               11
much daylight between Strickland’s deficiency prong and its
prejudice prong.” Waters, 896 F.3d at 570. That is because
“[i]f appellate counsel reasonably opts not to raise an issue with
little or no likelihood of success, then there is usually no
reasonable probability that raising the issue would have
changed the result of a defendant’s appeal.” Id. (quotation
marks omitted).

     Johnson rests his Strickland claims on Sullivan’s failure to
raise two arguments in the direct appeal: first, that the
government concealed exculpatory and impeachment evidence
in violation of Brady; and second, that Sullivan failed to
provide effective assistance at trial.

                                1

     The government violates Brady when it “(i) fails to
disclose to the defense, whether willfully or inadvertently, (ii)
exculpatory or impeachment evidence that is favorable to the
accused, and (iii) the withholding of that information
prejudices the defense.” United States v. Straker, 800 F.3d
570, 603 (D.C. Cir. 2015) (per curiam). Prejudice exists if the
withheld evidence is material, which requires “a reasonable
probability that, had the evidence been disclosed to the defense,
the result of the proceeding would have been different.” United
States v. Johnson, 519 F.3d 478, 488 (D.C. Cir. 2008)
(quotation marks omitted). When the government withholds
multiple pieces of evidence, we consider their materiality
cumulatively. Kyles v. Whitley, 514 U.S. 419, 436–37 (1995).

     Johnson contends that Sullivan should have raised Brady
claims based on the government’s failure to timely disclose
various pieces of evidence: first, shortly before Johnson’s
indictment, Williams was arrested on robbery charges that the
government declined to prosecute; second, Williams and Keith
                               12
Nash both had extensive criminal backgrounds; third, Gary was
a paid government informant, carried a gun on the night of the
shootings, and had a case against her dismissed based on the
intervention of a detective who testified at trial; fourth, Rowel
agreed to speak to the police only after Gary assaulted her.
Johnson contends that this evidence would have bolstered his
claim that Williams pulled the gun used to kill Nash and would
have helped him to impeach the government’s witnesses.

     Contrary to Johnson’s arguments, there is almost no
chance that this evidence, much of which was presented to the
jury, would have changed the outcome of the trial if all of it
had been timely disclosed to the defense. All four of the
surviving witnesses other than Johnson agreed on the essential
events of the shootings. Moreover, none of the Brady evidence
would have undercut the testimony of Sharon Nash. And it is
especially unlikely that she would have perjured herself to
protect Williams if it was Williams—rather than Johnson—
who was responsible for killing her brother and seriously
wounding her as well.

     Finally, and critically, undisputed forensic evidence
showed that Johnson was the killer. First, recall the seating
arrangements in the car at the time of the shootings. Everyone
agreed that Keith Nash was driving, Johnson was seated in the
far-left rear seat, and Williams was in the far-right rear seat.
Sharon Nash, Williams, Gary, and Rowel all testified that
Sharon was in the front passenger seat, while Johnson testified
that she was in the rear passenger seat to the left of Williams.
Next, consider the evidence about the Nashes’ injuries. A
medical examiner testified that Keith was shot twice on the left
side of his neck, with one of the shots passing through his right
lower cheek. Based on the soot rings on Keith’s neck, he
concluded that the shots were fired from three to four inches
away. Sharon was shot just beneath her left breast.
                                13
      Now compare that evidence with the two accounts offered
at trial. Everyone but Johnson testified that Johnson, while
sitting behind Keith or partially out of the driver’s side rear
door, put a gun to the back of Keith’s neck while he was in the
driver’s seat. Then Johnson shot Keith twice and fired another
shot into the car, which struck Sharon as she sat in the front
passenger seat. That testimony was entirely consistent with the
evidence that Keith was shot twice on the left side of his neck
from very close range and that Sharon was shot in her left side.

     Johnson’s testimony was that Williams, from the far-right
rear seat, pulled a gun on him. In response, Johnson reached
over two other passengers, to Williams on the right side of the
car, and tried to push the gun away. Then, during the ensuing
struggle between Johnson and Williams, bullets from
Williams’s gun hit Keith in the driver’s seat and Sharon, who
Johnson says was sitting to the left of Williams. This testimony
is inconsistent with the forensic evidence. Most damningly, it
cannot explain how Keith was shot in the left side of his neck
from a three- to four-inch distance. Nor, if Sharon was seated
to the left of Williams in the crowded back seat, can it account
for how a bullet struck her left side. None of the Brady material
could alter these basic physical realities.

     For these reasons, the disputed evidence was immaterial,
so a Brady claim would have lost on appeal. And Sullivan was
not ineffective “by declining to pursue a losing argument.”
United States v. Watson, 717 F.3d 196, 198 (D.C. Cir. 2013).

                                 2

     Johnson’s final argument is that Sullivan was ineffective
on appeal in failing to argue that he had been ineffective at trial.
The supposed ineffectiveness at trial involved Sullivan’s
failure to pursue the Brady material discussed above. This
                                14
point simply repackages the losing Brady argument. Because
the disputed evidence was immaterial, Sullivan’s failure to
pursue it did not prejudice Johnson. And because a claim of
ineffective trial counsel thus would have been unsuccessful,
Sullivan was not ineffective in omitting it from the appeal.

                       *    *        *   *

     Because Johnson was not denied the effective assistance
of appellate counsel, we affirm the district court’s judgment.

                                                  So ordered.
