                 FOR PUBLICATION
 UNITED STATES COURT OF APPEALS
      FOR THE NINTH CIRCUIT

DUNG THE PHAM,                           No. 03-17214
             Petitioner-Appellant,
               v.                          D.C. No.
                                         CV-02-01348-PJH
C. A. TERHUNE,
                                            OPINION
            Respondent-Appellee.
                                     
       Appeal from the United States District Court
          for the Northern District of California
       Phyllis J. Hamilton, District Judge, Presiding

                 Argued and Submitted
      September 17, 2004—San Francisco, California

                   Filed March 7, 2005

    Before: Robert R. Beezer, William A. Fletcher, and
            Raymond C. Fisher, Circuit Judges.

                   Per Curiam Opinion




                           2697
2700                   PHAM v. TERHUNE
                         COUNSEL

Cliff Gardner, San Francisco, California, for the petitioner-
appellant.

Glenn R. Pruden, OFFICE OF THE CALIFORNIA ATTOR-
NEY GENERAL, San Francisco, California, for the
respondent-appellee.


                         OPINION

PER CURIAM:

   Dung The Pham, a California state prisoner, appeals the
district court’s denial of his 28 U.S.C. § 2254 petition for a
writ of habeas corpus. In 1998, a jury convicted Pham and his
co-defendant, Son Hoang Nguyen, of first degree murder.
Pham was sentenced to a term of 29 years to life.

   The State and Pham agree that Tong Nguyen was murdered
by two gunmen, and that one of the gunmen was Tien Ha,
who remains at large. At trial, Pham presented a defense argu-
ing that another man, Hoang Tuan, was the second shooter.
On the basis of a license plate identification, Tuan was
arrested on the night of the murder. An eyewitness had also
identified Tuan as one of the assailants in a photo lineup.
While in police custody, Tuan was subjected to a gunshot res-
idue (GSR) test, which was analyzed by state criminalist
Mario Soto. Tuan was later released from custody and was
never charged with Nguyen’s murder.

   At Pham’s trial, the defense called Soto as a witness. Soto
testified that Tuan’s hands contained several particles consis-
tent with, but not unique to, GSR as well as one particle —
a mixture of titanium and antimony with a molten appearance
— inconsistent with GSR. Stating that he was unable to rule
                        PHAM v. TERHUNE                      2701
out environmental sources, Soto testified that the GSR test
was inconclusive. Soto further testified that if he had found a
molten-looking particle containing barium, lead, and anti-
mony or barium and antimony, he could testify conclusively
to the presence of GSR. Prior to trial, Pham’s attorney
requested in a letter that the state disclose expert reports,
statements, and test results, including criminalists’ notes.
Although the state disclosed Soto’s one-page report of conclu-
sions regarding the GSR test, it did not disclose the underly-
ing laboratory notes or raw data before trial, and Pham’s trial
counsel did not seek a court order mandating disclosure. Since
trial, the state has consistently refused Pham’s repeated
requests for the laboratory notes.

   Pham exhausted his claims in state court and filed this
amended habeas petition in the district court. The district
court denied the petition. Pham appeals, arguing that the dis-
trict court erred in finding that the government’s failure to dis-
close the underlying notes did not violate Brady v. Maryland,
373 U.S. 83 (1963). In his briefing of several uncertified
issues, Pham further argues that the district court abused its
discretion by declining to order discovery of the notes under
Rule 6(a) of the Federal Rules Governing Section 2254 Cases
(“Rule 6(a)”) and erred in denying his ineffective assistance
of counsel claim. He also argues that the trial court’s jury
instructions violated his rights to due process and trial by jury.

   [1] This court reviews de novo the district court’s decision
to deny a 28 U.S.C. § 2254 habeas petition. Clark v. Murphy,
331 F.3d 1062, 1067 (9th Cir. 2003). Denial of a discovery
request under Rule 6(a) is reviewed for abuse of discretion.
See Jones v. Wood, 114 F.3d 1002, 1009 (9th Cir. 1997).
Because Pham’s habeas petition was filed on March 19, 2002,
after the effective date of the Antiterrorism and Effective
Death Penalty Act (“AEDPA”), Pub. L. No. 104-132, 110
Stat. 1214 (1996), AEDPA’s provisions apply. See Delgado
v. Lewis, 223 F.3d 976, 979 (9th Cir. 2000). Under AEDPA,
the scope of review in a habeas case is limited to those issues
2702                   PHAM v. TERHUNE
specified in the certificate of appealability (COA). Nardi v.
Stewart, 354 F.3d 1134, 1137 (9th Cir. 2004). The district
court granted a COA only with respect to the Brady issue
raised in Pham’s habeas petition. Although Pham’s Rule 6(a)
discovery request, like his Brady claim, involves the state’s
suppression of the laboratory notes, it is unclear whether the
Rule 6(a) argument falls within the scope of the COA granted
on the Brady issue.

   However, under Ninth Circuit Rule 22-1(e), a habeas peti-
tioner may move to expand the COA by presenting uncerti-
fied issues, under a separate heading, in his opening brief.
“Uncertified issues raised and designated in this manner will
be construed as a motion to expand the COA and will be
addressed by the merits panel to such extent as it deems
appropriate.” Ninth Circuit Rule 22-1(e). In evaluating a
request to broaden a COA, this court must determine whether
the petitioner has made a “substantial showing of the denial
of a constitutional right.” Nardi, 354 F.3d at 1138 (quoting
Hiivala v. Wood, 195 F.3d 1098, 1104 (9th Cir. 1999)).

   [2] It is possible to construe the COA that has been granted
on the Brady issue to include the Rule 6(a) discovery issue,
because the notes sought are directly relevant to the Brady
issue. The state has briefed the discovery issue and stated at
oral argument that it does not need to brief it further.
Although we are not certain that we need to do so, out of
abundance of caution we grant Pham’s motion to expand the
COA to encompass his Rule 6(a) claim.

   Under AEDPA, this court must “defer to the state court’s
determination of the federal issues unless that determination
is ‘contrary to, or involved an unreasonable application of,
clearly established Federal law.’ ” Himes v. Thompson, 336
F.3d 848, 852 (9th Cir. 2003) (quoting Lockyer v. Andrade,
538 U.S. 63, 71 (2003)); see also 28 U.S.C. § 2254(d)(1). In
reviewing a state court’s summary denial of a habeas petition,
this court must “look through” the summary disposition to the
                        PHAM v. TERHUNE                       2703
last reasoned decision. See Shackleford v. Hubbard, 234 F.3d
1072, 1079 n.2 (9th Cir. 2000) (citing Ylst v. Nunnemaker,
501 U.S. 797, 803-04 (1991)). However, when no reasoned
state court decision denying a habeas petition exists, the fed-
eral court should “perform an ‘independent review of the
record’ to ascertain whether the state court decision was
objectively unreasonable.” Himes, 336 F.3d at 853 (quoting
Delgado, 223 F.3d at 982).

   [3] In evaluating Pham’s Rule 6(a) request for discovery of
the laboratory notes, the district court stated that “[w]ere this
not a petition for writ of habeas corpus, the court would be
inclined to grant Pham’s request for discovery.” Under the
misapprehension that the state court had refused to issue an
order requiring disclosure of the notes, the district court con-
cluded that it was required “to afford more stringent deference
to the state appellate court, which upheld suppression of the
lab notes, than that of an appellate court reviewing the deci-
sion of a trial court on direct appeal.” The district court erred
in applying this “stringent deference” to Pham’s Rule 6(a)
claim because there was no state court decision refusing to
order production of the notes. Pham’s trial counsel informally
requested the notes from the state both before and after trial
but never sought a court order to obtain them.

   [4] The district court thus erred in using the highly deferen-
tial AEDPA standard in denying Pham’s Rule 6(a) discovery
request. Rule 6(a) provides that a habeas petitioner is entitled
to discovery “if, and to the extent that, the judge in the exer-
cise of his discretion and for good cause shown grants leave
to do so, but not otherwise.” Rule 6(a). The Supreme Court
has stated that Rule 6(a) “is meant to be ‘consistent’ ” with its
holding in Harris v. Nelson, 394 U.S. 286 (1969), in which
the Court held that “where specific allegations before the
court show reason to believe that the petitioner may, if the
facts are fully developed, be able to demonstrate that he is . . .
entitled to relief, it is the duty of the court to provide the nec-
essary facilities and procedures for an adequate inquiry.”
2704                    PHAM v. TERHUNE
Bracy v. Gramley, 520 U.S. 899, 908-09 (1997) (quoting Har-
ris, 394 U.S. at 300) (alteration in original). Likewise, we
have held that a district court abused its discretion in not
ordering Rule 6(a) discovery when discovery was “essential”
for the habeas petitioner to “develop fully” his underlying
claim. Jones, 114 F.3d at 1009.

   [5] The laboratory notes are “essential” to the full develop-
ment of Pham’s Brady claim within the meaning of Jones
because they may well contain favorable, material informa-
tion that would tend to exculpate Pham by inculpating Hoang.
Specifically, Pham contends that titanium and barium are par-
ticularly difficult to distinguish, and that Soto may have mis-
taken barium for titanium when conducting his analysis. This
potential error, if caught, would result in a conclusive finding
of GSR. While a conclusive finding of GSR does not prove
that Hoang actually fired a gun, such forensic evidence would
significantly bolster the defense theory of the case. In light of
the significant amount of other evidence tending to inculpate
Hoang, we cannot say that an increased probability of
Hoang’s having fired a gun would be immaterial under Brady.

   [6] We do not reach the merits of Pham’s Brady claim. To
obtain Rule 6(a) discovery of the laboratory notes, Pham need
not demonstrate that he will ultimately prevail on his underly-
ing Brady claim. See Bracy, 520 U.S. at 909 (“It may well be,
as the Court of Appeals predicted, that petitioner will be
unable to obtain evidence sufficient to support a finding of
actual judicial bias in the trial of his case, but we hold that he
has made a sufficient showing . . . to establish ‘good cause’
for discovery.”). Once Soto’s notes have been disclosed, the
Brady issue is for the district court to decide in the first
instance. Nor do we reach Pham’s motions to broaden the
COA to include his claims for ineffective assistance of coun-
sel and violation of his rights to due process and jury trial.
However, our failure to reach these motions at this time is
without prejudice to their being made at a later time.
                       PHAM v. TERHUNE                      2705
   Appellant’s motion to expand the COA to include the Rule
6(a) issue should be granted. We therefore set aside the denial
of the petition for the writ of habeas corpus and remand to the
district court for further proceedings consistent with this opin-
ion.

  The district court’s order is VACATED, and the case is
REMANDED to the district court.
