 pniieb $infee 0,louri of appeals
         FOR THE DISTRICT OF COLUMBIA CIRCUIT



Argued September 24,2009              Decided June 28,2010




 BARACK
      OBAMA,
           PRESIDENT THE UNITED
                   OF         STATES, AL.,
                                    ET
                APPELLEES


        Appeal from the United States District Court
                for the District of Columbia
                 (NO. 1:04-CV-0 166-RJL)
                                  1



    Mark C. Fleming argued the cause for appellant. With
him on the briefs were Stephen H. Oleskey, Robert C. Kirsch,
Joshua D. Jacobson, Allyson J. Portney, Seth P. Waxman,
Paul R. Wolfson, Robert J. McKeehan, Douglas F. Curtis, and
Paul M. Winke.

    Sharon Swingle, Attorney, U.S. Department of Justice,
argued the cause for appellees. With her on the brief were
Michael F. Hertz, Deputy Assistant Attorney General, and
Douglas N.Letter, Thomas M. Bondy, and Robert M. Loeb,
Attorneys. Ronald J. Wiltsie 1 , Attorney, entered an
                                 1
appearance.
  Before: GINSBURG HENDERSON,
                    and       Circuit Judges, and
EDWARDS,Senior Circuit Judge.

    Opinion for the Court filed by Circuit Judge GINSBURG.

     GINSBURG, Circuit Judge:            Belkacem Bensayah
petitioned the district court for a writ of habeas corpus in
order to challenge his detention at the Naval Station at
Guantanamo Bay, Cuba. The district court denied his
petition, holding the Government had shown by a
preponderance of the evidence that Bensayah was being held
lawfully pursuant to the Authorization for Use of Military
Force (AUMF), Pub. L. 107-40, 5 2(a), 115 Stat 224, 224
(2001), because he had provided "support" to a1 Qaeda.
Boumediene v. Bush, 579 F. Supp. 2d 191, 198 (2008). On
appeal the Government has eschewed reliance upon certain
evidence the district court had considered and has abandoned
its position that Bensayah's detention is lawful because of the
support he rendered to a1 Qaeda; instead it argues only that his
detention is lawful because he was "part of' that organization
- a contention the district court did not reach.


     We agree with the Government that its authority under
the AUMF extends to the detention of individuals who are
functionally part of a1 Qaeda. The evidence upon which the
district court relied in concluding Bensayah supported a1
Qaeda is insufficient, however, to show he was part of that
organization. We therefore remand this case for the district
court to determine whether, considering all reliable evidence,
Bensayah was functionally part of a1 Qaeda.

                        I. Background

    Bensayah, an Algerian citizen, was arrested by the
Bosnian police on immigration charges in late 2001. He was
later told that he and five other Algerian men arrested in
Bosnia were suspected of plotting to attack the United States
Embassy in Sarajevo. Because the ensuing three-month
investigation failed to uncover evidence sufficient to continue
the detention of the six men, the Supreme Court of the
Federation of Bosnia and Herzogovina ordered that they be
released. The men were then turned over to the United States
Government and transported to the U.S. Naval Station at
Guantanamo Bay, where they have been detained since
January 2002.

     In 2004 Bensayah and the five other detainees petitioned
the district court for writs of habeas corpus. Although their
petitions were originally dismissed, Khalid v. Bush, 355 F.
Supp. 2d 3 11, 3 14 (D.D.C. 2005), they were reinstated after
the Supreme Court held that detainees at Guantanamo Bay are
constitutionally "entitled to the privilege of habeas corpus to
challenge the legality of their detention," Boumediene v.
Bush, 128 S. Ct. 2229,2262 (2008).

     In August 2008 the district court entered a case
management order (CMO) establishing the procedures that
would govern this case. See CMO, Boumediene v. Bush, No.
04-1 166 (RJL) (D.D.C. Aug. 27, 2008). The CMO placed
upon the Government the burden of establishing, by a
preponderance of the evidence, the lawfulness of the
petitioner's detention. The Government was required to
submit a return stating the factual and legal bases for
detaining that prisoner, who was then required to file a
traverse stating the relevant facts in support of his petition and
a rebuttal of the Government's legal justification for his
detention. The CMO allowed discovery only "by leave of the
Court for good cause shown," and required that requests for
discovery
    (I) be narrowly tailored; (2) specify why the request
    is likely to produce evidence both relevant and
    material to the petitioner's case; (3) specify the
    nature of the request ...; and (4) explain why the
    burden on the Government to produce such evidence
    is neither unfairly disruptive nor unduly burdensome.

It also required the Government to provide to the petitioner
any exculpatory evidence "contained in the material reviewed
in developing the return for the petitioner[] and in preparation
for the hearing for the petitioner."

     The Government claimed authority to detain the six men
pursuant both to the AUMF and to the President's inherent
powers as Commander in Chief. It argued each of the six
men was lawfully detained as an "enemy combatant," which
the district court had in an earlier order defined as

    an individual who was part of or supporting Taliban
    or a1 Qaeda forces, or associated forces that are
    engaged in hostilities against the United States or its
    coalition partners. This includes any person who has
    committed a belligerent act or has directly supported
    hostilities in aid of enemy armed forces.

Boumediene v. Bush, 583 F. Supp. 2d 133, 135 (2008). The
Government contended all six men were lawfully detained
because they had planned to travel to Afghanistan in late 2001
in order to take up arms against the United States and allied
forces. It also contended Bensayah's detention was lawful
because he was a member of and a travel facilitator for a1
Qaeda. The only direct evidence the Government offered in
sumort of its contentions about Bensavah was contained in a

unnamed source and in certain other pieces of evidence it
claimed corroborated that document.
     The district court granted habeas to each petitioner other
than Bensayah, holding the Government had failed to show by
a preponderance of the evidence that they had planned to
travel to Afghanistan to fight against the United States.
Boumediene, 579 F. Supp. 2d at 197-98. Because the
Government did not sufficiently establish the reliability of the
allegations in the classified document about those petitioners,
the court refused to credit those allegations.

     The district court denied Bensayah's petition because it
determined "the Government has met its burden by providing
additional evidence that sufficiently corroborates its
allegations from this unnamed source that Bensayah is an al-
Qaida facilitator." Id. at 198. The corroborative evidence
provided by the Government is of three sorts: (1) evidence
linking Bensayah to a1 Qaeda, and specifically to a "senior al-
Qaida fa~ilitator'~; evidence of Bensayah's history of
                     (2)
travel "between and among countries using false passports in
multiple names"; and (3) evidence creating "sufficient doubt
as to Bensayah's credibility." Id.

     Having deemed the allegations about Bensayah in the
classified document reliable, the district court held "the
Government has established by a preponderance of the
evidence that it is more likely than not ... Bensayah not only
planned to take up arms against the United States but also
[planned to] facilitate the travel of unnamed others to do the
same." Id. The court further held such planning and
facilitating "amounts to 'support' within the meaning of the
'enemy combatant' definition governing this case." Id.
Because it held Bensayah's detention was lawful based upon
his support of a1 Qaeda, the court did not go on to consider
whether he was a "member" of a1 Qaeda or whether his
detention was lawful on the alternative ground that he was
"part o f ' that organization.
     There have been three developments since the district
court's decision. First, the Government has eschewed
reliance upon a portion of the evidence that the "senior al-
Qaida facilitator" with whom Bensayah allegedly had contact
was in fact a senior a1 Qaeda facilitator. Second, the
Government has changed its position concerning the source
and scope of its authority to detain Bensayah. Whereas the
Government had previously claimed authority to detain
Bensayah based upon both the AUMF and the President's
constitutional authority as Commander in Chief, it now relies
solely upon the AUMF.* Third, the Government has
abandoned its argument that Bensayah is being detained
lawfully because of the support he rendered to a1 Qaeda -
the sole basis upon which the district court denied Bensayah's
petition. The Government now contends that Bensayah's
detention is lawful only because he was "part o f ' a1 Qaeda.

                            11. Analysis

     Some but not all Bensayah's many arguments on appeal
were mooted when the Government abandoned its theory that
Bensayah's detention is lawful because he rendered support to
a1 Qaeda. As for matters of procedure, Bensayah still
challenges the district court's (1) reliance upon the
preponderance of the evidence standard, (2) refusal to require
the Government to search for reasonably available
exculpatory evidence in its possession, (3) denial of his

* The Government has also abandoned the term "enemy combatant"
in reference to the scope of its detention authority and now claims
the authority to detain individuals who "were part of, or
substantially supported, Taliban or al-Qaida forces or associated
forces that are engaged in hostilities against the United States or its
coalition partners, including any person who has committed a
belligerent act, or has directly supported hostilities, in aid of such
eneniy armed forces."
discovery requests, and (4) admission of the Government's
"rebuttal" evidence. As for matters of substance, Bensayah
still argues the district court erred in (1) adopting an
overbroad definition of the Executive's detention authority,
and (2) crediting "inadequately corroborated raw
intelligence." Even if that evidence is credited, he argues (3)
it is insufficient to establish his detention is lawful.

     We review de novo the district court's conclusions of
law, including its ultimate denial of a writ of habeas corpus.
Saunders v. Senkowski, 587 F.3d 543, 547 (2d Cir. 2009). We
review its factual determinations for clear error, id., and its
evidentiary rulings for abuse of discretion, A1 Odah v. United
States, 559 F.3d 539, 544 (D.C. Cir. 2009). Whether a
detainee was "part o f ' a1 Qaeda is a mixed question of law
and fact. Awad v. Obama, No. 09-535 1, slip op. at 17 (June 2,
2010). "That is, whether a detainee's alleged conduct ...
justifies his detention under the AUMF is a legal question.
The question whether the [Glovernment has proven that
conduct ... is a factual question that we review for clear
error." Barhoumi v. Obama, No. 09-5383, slip op. at 12-13
(June 11, 20 10) (internal citation deleted).

A. Standard of Proof

    In Boumediene the Supreme Court held detainees at
Guantanamo Bay are entitled to "the fundamental procedural
protections of habeas corpus," 128 S. Ct. at 2277, but did not
expand upon which procedural protections are "fundamental."
It left open, for instance, the standard of proof the
Government must meet in order to defeat a petition for habeas
corpus. Id. at 2271 ("The extent of the showing required of
the Government in these cases is a matter to be determined").
Bensayah argues that because he is liable to be held "for the
duration of hostilities that may last a generation or more,"
requiring the Government to prove the lawfulness of his
detention by a mere preponderance of the evidence is
inappropriate. He contends the district court should have
required the Government to prove its case beyond a
reasonable doubt, or at least by clear and convincing
evidence. This argument has been overtaken by events, for
we have recently held a standard of proof higher than a
preponderance of the evidence is not a "fundamental
procedural protection" of habeas required by Boumediene.
Awad, slip op. at 18 ("A preponderance of the evidence
standard satisfies constitutional requirements in considering a
habeas petition from a detainee held pursuant to the AUMF");
Al-Bihani v. Obama, 590 F.3d 866, 878 (2010) ("Our narrow
charge is to determine whether a preponderance standard is
unconstitutional. Absent more specific and relevant guidance,
we find no indication that it is.").

B. Challenges to the Discovery Process

    The CMO requires the Government to

    provide on an ongoing basis any evidence contained
    in the material [it] reviewed in developing the return
    for the petitioner, and in preparation for the hearing
    for the petitioner, that tends materially to undermine
    the Government's theory as to the lawfulness of the
    petitioner's detention.

Bensayah argues the district court abused its discretion by
imposing upon the Government an impermissibly narrow
obligation to disclose exculpatory evidence. He maintains the
Government must search all "reasonably available"
information and disclose not only information that "tends
materially to undermine the Government's theory as to the
lawfulness of the petitioner's detention" but also information
that "undermines the reliability of other purportedly
inculpatory evidence" or "names potential witnesses capable
of providing material evidence."

     Bensayah does not contend the disclosure requirement
imposed by the district court is in any way unconstitutional.
Nor has he shown that broader disclosure is required by any
opinion of the Supreme Court or of this court. He cites
Bismullah v. Gates, 503 F.3d 137, 138-39 (D.C. Cir. 2007),
for the proposition that the Government must search all
"reasonably available" information, but that decision was
compelled by the terms of a statutory scheme not at issue
here. He cites A1 Odah, 559 F.3d at 546, for the proposition
that evidence may be material even if it is not directly
exculpatory. The CMO is not, however, in tension with A1
Odah. Information that undermines the reliability of other
materials, e.g., inculpatory evidence, see id. at 546, also tends
"materially to undermine the Government's theory as to the
lawfulness of the petitioner's detention" and hence must be
disclosed by the Government. We therefore agree with the
Government that the standard for disclosure ordered by the
district court, coupled with the opportunity to make specific
discovery requests, is consistent with the Supreme Court's
directive in Boumediene that a detainee be provided with the
opportunity to challenge "the sufficiency of the Government's
evidence" and to "supplement the record on review" with
additional "exculpatory evidence." 128 S. Ct. at 2270,2274.

     Bensayah's primary concern seems to be that the
disclosure requirement allows the Government to withhold
exculpatory evidence because personnel from other agencies
will pass only inculpatory evidence on to the attorneys
actually "developing the return" and "preparing for the
hearing." That practice is not permissible, however, under the
current disclosure requirement. Any information that has
been strategically filtered out of the record in order to
withhold exculpatory evidence is plainly "material reviewed
in developing the return" -- and hence subject to the
disclosure requirement - even if the individual doing the
filtering works for a Government agency other than the
Department of Justice.

     Bensayah next argues that the district court erred by
placing upon him the burden of explaining why each of his
discovery requests would be neither "unfairly disruptive [nor]
unduly burdensome to the Government." The district court
did not abuse its discretion in structuring discovery this way.
The Supreme Court specifically recognized the district court's
discretion to accommodate the Government's legitimate
interest in protecting sources and intelligence-gathering
methods, acknowledging that "[clertain accommodations can
be made to reduce the burden habeas corpus proceedings will
place on the military without impermissibly diluting the
protections of the writ." Bournediene, 128 S. Ct. at 2276. It is
not necessary to address Bensayah's specific discovery
requests relating to              because, as explained below,
we hold this exhibit may not be relied upon by the district
court on remand in the absence of additional corroborative
evidence.      Any discovery requests pertaining to new
corroborative evidence should be decided by the district court
in the first instance. Finally, we find no merit in Bensayah's
claims the district court abused its discretion in denying his
request for discovery into the treatment of                or in
allowing the Government to present "rebuttal" evidence.

C. Standard of Detention

    The Government asserts the authority to detain Bensayah
pursuant to the AUMF, in which the Congress authorized the
President
    to use all necessary and appropriate force against
    those nations, organizations, or persons he
    determines planned, authorized, committed, or aided
    the terrorist attacks that occurred on September 11,
    2001, or harbored such organizations or persons, in
    order to prevent any future acts of international
    terrorism against the United States by such nations,
    organizations or persons.

As mentioned before, the Government contends it may
lawfully detain an individual if he is "part o f ' a1 Qaeda.
Bensayah objects to this formulation, but we have made clear
elsewhere that the AUMF authorizes the Executive to detain,
at the least, any individual who is functionally part of a1
Qaeda. Barhoumi, slip op. at 29 (detainee "was 'part o f an
al-Qaida-associated force and therefore properly detained
pursuant to the AUMF"); Awad, slip op. at 19 ("Once [a
petitioner is shown to be] 'part o f a1 Qaeda ... the
requirements of the AUMF [are] satisfied"); Al-Bihani, 590
F.3d at 872-74.

     Although it is clear a1 Qaeda has, or at least at one time
had, a particular organizational structure, see The 911 1
Commission Report: Final Report of the National
Commission on Terrorist Attacks upon the United States 56
(2004) ("[Al Qaeda's] structure included as its operating arms
an intelligence component, a military committee, a financial
committee, a political committee, and a committee in charge
of media affairs and propaganda"), the details of its structure
are generally unknown, see Audrey Kurth Cronin,
Congressional Research Service Report for Congress: A1
Qaeda After the Iraq Conflict (2003) ("There is a great deal
that remains unknown or debatable about the specific nature,
size, structure and reach of [a1 Qaeda]"), but it is thought to be
somewhat amorphous, Kenneth Katzman, Congressional
Research Service Report for Congress: A1 Qaeda: Profile and
Threat Assessment (2005) ("A1 Qaeda has always been more
a coalition of different groups than a unified structure, many
argue, and it has been this diversity that gives A1 Qaeda
global reach"). As a result, it is impossible to provide an
exhaustive list of criteria for determining whether an
individual is "part of' a1 Qaeda. That determination must be
made on a case-by-case basis by using a functional rather than
a formal approach and by focusing upon the actions of the
individual in relation to the organization. That an individual
operates within a1 Qaeda's forrnal command structure is
surely sufficient but is not necessary to show he is "part o f '
the organization; there may be other indicia that a particular
individual is sufficiently involved with the organization to be
deemed part of it, see Awad, slip op. at 19 ("there are ways
other than making a 'command structure' showing to prove
that a detainee is 'part o f a1 Qaeda"), but the purely
independent conduct of a freelancer is not enough.

D. Sufficiency of the Evidence

                               - 1
    As the district court noted, a
                               is the only evidence directly



REPORT.          NOT          FINALLY           EVAULATED




                  contains a number of allegations about
Bensayah. It states:
     The district court, quoting Parhat v. Gates, 532 F.3d 834,
847 (D.C. Cir. 2008), correctly stated that it must "evaluate
the raw evidence, finding it to be sufficiently reliable and
sufficiently probative to demonstrate the truth of the asserted
proposition with the requisite degree of certainty." See
Barhoumi, slip op. at 21 ("we agree ... Parhat sets the
guideposts for our inquiry into the reliability of the ...
evidence [in a detainee's habeas case]"). Although the district



about the source of the document and about how the
information therein was gathered led the court to conclude
           is not by itself reliable.

     In Parhat we made clear that the reliability of evidence
can be determined not only by looking at the evidence alone
but, alternatively, by considering "sufficient additional
information ... permit[ting the factfinder] to assess its
reliability." 532 F.3d at 849. Here the district court, after
looking at additional information, concluded "there is
sufficient corroborating evidence in the record to credit and
rely upon the[] assertions made in                        about
Bensayah." The evidence in question is of three sorts: (1)




                                          -
evidence linking Bensayah to a1 Qaeda, and specifically to
,                 allegedly a "senior al-Qaida operative and




                                          -
facilitator"; (2) evidence of Bensayah's travel plans and travel
history; and (3) evidence raising "questions ... about
Bensayah's whereabouts in the early 1990s," which evidence
created "sufficient doubt as to Bensayah's credibility."

     Bensayah argues the district court clearly erred by

a-
finding             reliable. He contends the
                   upon which the district court relied were
categorically insufficient to corroborate
I.                                         We disagree with
~ G s a ~ a h broad contention that two pieces of evidence,
              's
each unreliable when viewed alone, cannot ever corroborate
each other. Cf:United States v. Laws, 808 F.2d 92, 100-03
(D.C. Cir. 1986) (relying upon one informant's hearsay
statement to corroborate another informant's hearsay
statement even though neither was reliable standing alone).
We agree, however, with his alternative argument that even if
the additional evidence relied upon by the district court in this
case is itself reliable, it is not sufficiently corroborative to
support reliance upon the statements concerning Bensayah in
    1. Evidence Linking Bensayah to A1 Qaeda

     The district court found     fl
were corroborated by Bensayah's "connections" to a1 Qaeda,
viz., (1) Bensayah was directly linked to ,     -
allegedly a "senior al-Qaida operative and facilitator," and (2)




  -
put forth more than sufficient credible evidence that
            was a senior al-Qaida operative and facilitator."
Since the district court's decision, however, the Govemment




- -
has eschewed reliance upon much of that evidence; it now
maintains the other evidence upon which the district court
relied is sufficient to link              to a1 Qaeda. In an
order denying a Rule 60(b) motion filed by Bensayah, the
district court indicated it would have concluded
was sufficiently corroborated to be relied upon, even "putting
aside completely any evidence linking Bensayah to


    Assuming, as the Govemment contends,
was connected to a1 Qaeda, the evidence linking Bensayah to
              and a1 Qaeda does not, by itself or together
                                                   -
with the other evidence discussed below, corroborate
      sufficiently so that it can be relied upon. The
Government presented no direct evidence of actual
communication between Bensayah and any a1 Qaeda member,
much less evidence suggesting Bensayah communicated with
                 or anyone else in order to facilitate travel by
an a1 Qaeda member. Indeed, the district court determined the
record did not support the allegations in
concerning the only individuals named therein whose travel
Bensayah allegedly planned to facilitate.

    2. Travel History and Travel Plans

     The district court found the assertions in
were corroborated by evidence that Bensayah (1)
,
                                                   1
                                       and (2) had "experience
in obtaining and traveling in and out of numerous countries on
fraudulent passports." Bensayah admits to having used
multiple travel documents, "some of which were in an
assumed name," but maintains he traveled under fraudulent
documents in order to avoid being sent back to Algeria,
"where he reasonably feared persecution." He presented
"unrebutted declarations" that "mere possession and use of
false travel documents is neither proof of involvement with
terrorism nor evidence of facilitation of travel by others." We
amee. That Bensavah had ex~erience        with fraudulent travel



Qaeda or anyone else. As noted in the prior paragraph, the
district court determined the Government had failed to show
that Bensayah's co-petitioners planned to travel to
Afghanistan in order to engage U.S. forces. Therefore,
Bensayah could not have been facilitating their travel for that
purpose.
     3.Evidence Calling         into   Question     Bensayah's
       Credibility

     The district court found "serious questions [had] been
raised about Bensayah's whereabouts in the early 1990s."
This finding af-most undermines Bensayah's own credibility;
no account of his whereabouts ties him to a1 Qaeda or
suggests he facilitated anyone's travel during that time. These
"questions" in no way demonstrate that Bensayah had ties to
and facilitated travel for a1 Qaeda in 200 1.



    Because the evidence, viewed in isolation or together, is
insufficiently corroborative of ,           the district court
on remand may not, in the absence of additional corroborative
evidence not already considered, rely upon that exhibit in
determining whether Bensayah was part of a1 Qaeda.

                          111. Conclusion

     The Government argues it is authorized by the AUMF to
detain Bensayah solely on the ground he was functionally a
member or "part o f ' a1 Qaeda. The evidence upon which the
district court relied in concluding Bensayah "supported" a1
Qaeda is insufficient, however, to show he was part of that
organization. Accordingly, we reverse the judgment of the
district court and remand the case for the district court to hear
such evidence as the parties may submit and to decide in the
first instance whether Bensayah was functionally part of a1
Qaeda.

                                                    So ordered.
