                 FOR PUBLICATION
 UNITED STATES COURT OF APPEALS
      FOR THE NINTH CIRCUIT

JOSHUA RICHTER,                      
             Petitioner-Appellant,
                                          No. 06-15614
                v.
                                           D.C. No.
R. Q. HICKMAN, Warden; CAL A.            CV-01-00643-JKS
TERHUNE; ERNIE ROE,
           Respondents-Appellees.
                                     

CHRISTIAN BRANSCOMBE,                
             Petitioner-Appellant,        No. 06-15776
               v.
                                           D.C. No.
                                         CV-01-00643-JKS
R. Q. HICKMAN, Warden; CAL A.
TERHUNE; ERNIE ROE,                         OPINION
           Respondents-Appellees.
                                     
       Appeal from the United States District Court
          for the Eastern District of California
    James K. Singleton, Chief District Judge, Presiding

                 Argued and Submitted
       October 15, 2007—San Francisco, California

                   Filed April 9, 2008

      Before: Robert R. Beezer, Stephen S. Trott, and
              N. Randy Smith, Circuit Judges.

                 Opinion by Judge Beezer



                           3657
                      RICHTER v. HICKMAN                   3661


                         COUNSEL

Cliff Gardner, Oakland, California, for petitioner-appellant
Joshua Richter.

Ann C. McClintock, Assistant Federal Defender, Sacra-
mento, California, for petitioner-appellant Christian Bran-
scombe.

Harry Joseph Colombo, Deputy Attorney General, and John
G. McLean, Supervising Deputy Attorney General, Sacra-
mento, California, for the respondents-appellees.


                          OPINION

BEEZER, Circuit Judge:

   Appellants in these two consolidated cases were jointly
convicted of murder, attempted murder, robbery and burglary
in California state court. They were sentenced to life in prison
without the possibility of parole. In the present action, they
appeal the district court’s denial of writs of habeas corpus.
Appellants allege that they received ineffective assistance of
counsel at trial in violation of Strickland v. Washington, 466
U.S. 668 (1984). Appellants further allege that the prosecu-
tion suppressed exculpatory evidence at trial in violation of
Brady v. Maryland, 373 U.S. 83 (1963). Appellant Christian
Branscombe (“Branscombe”) argues that his trial counsel
failed to engage in “meaningful adversarial testing” in viola-
3662                  RICHTER v. HICKMAN
tion of United States v. Cronic, 466 U.S. 648 (1984). Appel-
lant Joshua Richter (“Richter”) alleges that the trial court vio-
lated his Eighth Amendment right to a jury trial and
Fourteenth Amendment right to due process by providing an
incorrect or inaccurate answer to a question of law posed by
the jury to the trial court. We affirm the district court’s denial
of appellants’ habeas petitions.

                                I

   Joshua Gunner Johnson (“Johnson”), a friend of Richter
and acquaintance of Branscombe, lived in a house in Sacra-
mento. On the evening of December 19, 1994, Richter and
Branscombe drove to Johnson’s house so that Richter could
pay Johnson some money he owed him and buy some mari-
juana from him. Richter and Branscombe were waiting in
their car in Johnson’s driveway when Johnson returned home,
accompanied by Patrick Klein (“Klein”) and another individ-
ual. Johnson did not recognize the car, and approached the car
with his .380 caliber Mac-12 handgun drawn. Upon recogniz-
ing the petitioners, Johnson put the Mac-12 away. Johnson,
Klein, Richter and Branscombe went into the house, where
they socialized for several hours. While they talked, Bran-
scombe cleaned a .32 caliber handgun that he had recently
acquired from either Johnson or Johnson’s housemate. Richter
and Branscombe left Johnson’s residence shortly after
2:30 a.m. on December 20, 1994. Klein decided to stay the
night.

   At trial, appellants and appellee State of California (“the
State”) presented different accounts of the ensuing events.
The State presented evidence that after Richter and Bran-
scombe left, Johnson went to sleep in his bedroom and Klein
lay down on the couch in the living room. Johnson woke up
early in the morning to find Richter and Branscombe in his
bedroom, likely attempting to steal Johnson’s gun safe, which
was allegedly located in Johnson’s bedroom closet. Bran-
scombe shot Johnson, and Johnson later heard gunshots com-
                      RICHTER v. HICKMAN                   3663
ing from another room. Johnson found Klein lying on the
couch bleeding and discovered that his Mac-12 was missing,
along with a hip sack that contained $6000 in cash.

   Richter and Branscombe presented evidence that they
returned to Johnson’s residence around 4:00 a.m. so they
could give Johnson’s housemate certain belongings and
wages, and so that Branscombe could return the .32 caliber
handgun. Richter stayed in his truck while Branscombe was
let into the house by Klein. Shortly thereafter, Richter heard
gunshots. He headed toward the house and heard more yelling
and gunshots as he approached the front door. Richter saw
Klein lying in the doorway to Johnson’s bedroom, and found
Branscombe “totally freaked out” standing in the middle of
the bedroom holding a firearm. Branscombe told Richter that
Johnson and Klein had fired at him and tried to kill him.
Branscombe picked up the Mac-12 from the floor and told
Richter that Johnson or Klein had fired it and had tried to
shoot him with it. Branscombe then ran outside and tried to
start the truck. Richter panicked and ran back out to the truck.
Richter and Branscombe drove away.

   Soon after the shootings, Johnson made a 911 call to police.
Before police arrived six minutes later, Johnson testified that
he made a phone call to his girlfriend’s father and took two
trips through the house and into the yard to hide his marijuana
plants. The police arrived at the house six minutes after John-
son’s 911 call. Upon arrival, they encountered a “hysterical”
Johnson, who had blood on his cheeks, shirt, hands and right
shoulder. The police saw Klein lying on top of a sleeping bag
on the living room couch, near death.

   A subsequent investigation found two spent .32 casings in
the bedroom where Johnson said he had been shot. The inves-
tigators found blood on the bed where Johnson said he had
been shot, and a pool of blood in the doorway to Johnson’s
bedroom. Investigators determined that Klein had been shot
twice, by a .22 and a .32 caliber bullet. They also found a
3664                  RICHTER v. HICKMAN
spent .32 and a spent .22 casing in the living room near the
couch where Klein was lying. Later, while searching Richter’s
residence, investigators found Johnson’s gun safe haphazardly
laying on its back. Investigators found a .380 casing in Rich-
ter’s vehicle which they determined had been ejected from
Johnson’s Mac-12.

   The weapons used to kill Klein and injure Johnson were
never found, but investigators examined the bullets fired and
casings ejected at the scene. The .22 bullet removed from
Klein was a CCI Stinger. The bullet had markings consistent
with being ejected from a High Standard Sport King, although
investigators could not rule out the possibility that the bullet
had been fired from a different .22 caliber firearm. Investiga-
tors also found a CCI Stinger brand .22 caliber casing in John-
son’s living room, near the couch where Klein was found by
the police. The casing had markings consistent with (but not
exclusive to) having been fired from a High Standard Sport
King. While searching Richter’s residence, investigators
found a magazine loaded with CCI Stinger brand .22 car-
tridges. The magazine was identical in size and shape to High
Standard magazines designed specifically for a Sport King.
An investigator successfully fired a laboratory exemplar High
Standard Sport King using the magazine found in Richter’s
residence.

   A California Superior Court jury found Richter and Bran-
scombe guilty of all charges after a trial lasting over three
weeks. Following their convictions, Richter and Branscombe
appealed to the California Court of Appeal, which affirmed
the judgments of the trial court. Appellants filed a petition for
review in the Supreme Court of California, which was denied.
Appellants sought writs of habeas corpus in the California
Supreme Court, which denied their petitions. Appellants
timely petitioned for writs of habeas corpus in the United
States District Court for the Eastern District of California,
which denied the petitions. Appellants sought certificates of
appealability from this court, which were granted.
                          RICHTER v. HICKMAN                          3665
                                    II

   Under the Antiterrorism and Effective Death Penalty Act of
1996 (“AEDPA”), we may not grant a habeas corpus petition
unless the state court decision “was contrary to, or involved
an unreasonable application of, clearly established Federal
law, as determined by the Supreme Court of the United States,”1
or “was based on an unreasonable determination of the facts
in light of the evidence presented in the State court proceed-
ing.” 28 U.S.C. § 2254(d). When reviewing a state court’s
summary denial of a habeas petition, we “look through” the
summary disposition to the last reasoned state court decision.
Plascencia v. Alameida, 467 F.3d 1190, 1198 (9th Cir. 2006).
When no state court has explained its reasoning on a particu-
lar claim, we conduct “an independent review of the record to
determine whether the state court’s decision was objectively
unreasonable.” Sass v. Cal. Bd. of Prison Terms, 461 F.3d
1123, 1127 (9th Cir. 2006).

   We review a district court’s decision to grant or deny a writ
of habeas corpus de novo. Lewis v. Mayle, 391 F.3d 989, 995
(9th Cir. 2004). We review the district court’s findings of fact
for clear error. Bonin v. Calderon, 59 F.3d 815, 823 (9th Cir.
1995).

                                    III

   Appellants argue that they were denied effective assistance
of trial counsel as guaranteed by the Sixth Amendment. Under
Strickland, petitioners claiming ineffective assistance of coun-
  1
    A state court decision is “contrary to” clearly established federal law
if the state court arrives at a conclusion opposite to that of the Supreme
Court of the United States on a question of law, or decides the case differ-
ently than the Supreme Court on a set of materially indistinguishable facts.
Williams v. Taylor, 529 U.S. 362, 405 (2000). A state court decision is an
“unreasonable application of” clearly established federal law if the state
court identified the correct governing legal rule but unreasonably applied
it to the facts at hand. Id. at 407.
3666                  RICHTER v. HICKMAN
sel must show both cause and prejudice to prevail on their
claim. 466 U.S. at 687.

   To show cause, petitioners must demonstrate that counsel’s
performance at trial was objectively unreasonable, i.e., “out-
side the wide range of professionally competent assistance.”
Id. at 688, 690. Judicial scrutiny of counsel’s performance
“must be highly deferential.” Id. at 689. Counsel is “strongly
presumed to have rendered adequate assistance.” Id. at 690.
Courts reviewing counsel’s performance “evaluate the con-
duct from counsel’s perspective at the time,” to “eliminate the
distorting effects of hindsight.” Id. at 689. Strategic choices
made by counsel after thorough investigation are “virtually
unchallengeable.” Id. at 690. A decision not to investigate
must be assessed for reasonableness, applying a heavy mea-
sure of deference to counsel’s judgments. Id. at 691.

   To show prejudice, petitioners must demonstrate there is a
“reasonable probability that, but for counsel’s unprofessional
errors, the result of the proceeding would have been differ-
ent.” Id. at 694. “When a defendant challenges a conviction,
the question is whether there is a reasonable probability that,
absent the errors, the factfinder would have had a reasonable
doubt respecting guilt.” Id. at 695.

                               A

   Appellants first argue that trial counsel rendered ineffective
assistance under Strickland by (1) failing to develop and pre-
sent testimony from firearms evidence experts, (2) failing to
develop and present expert testimony to contradict the state’s
serology evidence and (3) failing to develop and present testi-
mony from pathology experts. Appellants now submit decla-
rations from experts in each of these three areas to support
their assertion that they were prejudiced as a result of their
counsel’s failings.

  We need not decide whether appellants’ trial counsel acted
unreasonably in failing to consult and present experts in fire-
                        RICHTER v. HICKMAN                  3667
arms evidence, serology and pathology. Even assuming that
trial counsels’ failure to consult and present such experts was
unreasonable, appellants do not show that such failure preju-
diced their case.

                   1.    Firearms Evidence

  Appellants argue that their counsel rendered ineffective
assistance by failing to develop and present expert testimony
demonstrating that Johnson’s Mac-12 firearm was prone to
jamming.

   At trial, the defense argued that Johnson attempted to shoot
Branscombe with his Mac-12, but the weapon jammed
because an empty shell failed to eject. Evidence that the Mac-
12 had jammed would have bolstered the defense’s case by
providing a non-incriminating explanation for why Klein had
been hit by both a .32 caliber and a .22 caliber bullet. Accord-
ing to the defense’s theory at trial, after Johnson’s Mac-12
jammed, he grabbed his .22 handgun. While trying to shoot
Branscombe with the .22 as Branscombe struggled with
Klein, Johnson missed and hit Klein instead. Branscombe
then fired his .32 at both Klein and Johnson in self-defense.
The theory also provides the defense with an explanation for
why an empty shell from the Mac-12 was found in Richter’s
vehicle: the shell failed to eject when Johnson fired the hand-
gun at Branscombe, but ejected when Richter and Bran-
scombe examined it after leaving the scene of the shootings.

   At trial, the State’s criminalist, Robert Garbutt (“Garbutt”),
testified that he test-fired Johnson’s Mac-12 three times with-
out a misfire. On cross-examination, Garbutt testified that
modifications Johnson made to the Mac-12 could cause it to
“malfunction or fail to fire.” Garbutt also testified that he did
not know whether these modifications would specifically
cause a failure to eject the shell. Garbutt’s testimony provided
some support for the theory that Johnson accidentally shot
Klein with a .22 bullet, but failed to explain why an empty
3668                  RICHTER v. HICKMAN
shell, rather than an unfired bullet, was found in Richter’s
vehicle.

   Appellants now submit a declaration of an expert in fire-
arms evidence who would have testified that the type of alter-
ations made to Johnson’s Mac-12 “can cause the gun to fail
to eject a spent cartridge.”

   [1] Appellants’ counsel’s failure to have such an expert tes-
tify at trial did not prejudice their case. Even had the jury
heard the proffered expert’s testimony that the Mac-12 could
jam, there is no reasonable probability that the jury would
have accepted appellants’ theory that the Mac-12 did jam in
this case. The proffered expert offers no opinion on the actual
likelihood that such a modification would cause the weapon
to jam. Garbutt, the State’s own expert, admitted at trial that
the modifications to Johnson’s Mac-12 could possibly cause
it to fail to fire, but found that the weapon successfully fired
each of the three times that he tested it. To accept the appel-
lants’ theory, the jury would have had to find that (1) the
Mac-12 malfunctioned when Johnson tried to fire it at Bran-
scombe, even though it functioned normally when tested later,
(2) the .22 caliber bullet in Klein’s body came from a differ-
ent firearm belonging to Johnson instead of one belonging to
Richter, (3) the bullet from Johnson’s .22 caliber hit Klein
even though Johnson was attempting to shoot Branscombe,
(4) Johnson would attempt to fire two different firearms at
Branscombe, even though Branscombe had been a social
guest in Johnson’s house just hours before, (5) Klein would
attack or threaten Branscombe in a manner justifying Bran-
scombe’s shooting of Klein in self-defense, even though
Klein had been the person who let Branscombe into the house
minutes earlier and (6) it is mere coincidence that investiga-
tors found a magazine in Richter’s residence full of .22 CCI
Stinger cartridges—the same type as the casing found in
Johnson’s living room.

   [2] The totality of the evidence presented at trial weighs
strongly against appellants’ theory that the Mac-12 jammed
                      RICHTER v. HICKMAN                    3669
and that Branscombe fired at Klein in self-defense. There is
no reasonable probability that the jury would have changed its
verdict had they heard additional testimony stating that the
Mac-12 could possibly malfunction in some manner.

                         2.   Serology

   Appellants argue that their counsel rendered ineffective
assistance by failing to develop and present expert testimony
regarding the source of the pool of blood in the doorway to
Johnson’s bedroom. If the pool of blood included blood from
Klein, it would indicate that Klein had probably been killed
near the doorway, instead of on the living room couch. This
would contradict Johnson’s testimony that Klein had been
shot on the living room couch, and would instead support the
defense’s theory that Johnson had moved Klein to the couch
after the shootings. This would also support the defense’s the-
ory that Klein had been shot by an errant bullet from John-
son’s .22 caliber as Klein struggled with Branscombe in the
vicinity of the bedroom door.

   At trial, the State’s serology expert testified that evidence
taken from a sample of blood in the doorway confirmed that
the blood tested came exclusively from Johnson. Appellants
now submit the declarations of two serology experts stating
that they “could not exclude” the possibility that the blood
sample contained a mixture of Johnson’s and Klein’s blood.

   [3] There is no reasonable probability that the jury would
have rendered a different verdict had defendants’ proffered
serology experts testified at trial. The serology experts’ testi-
mony, even if believed, would not significantly weaken the
State’s case. All the testimony says is that it is possible that
the blood sample taken from the bedroom doorway might be
a mixture of Klein and Johnson’s blood, instead of being
exclusively Johnson’s blood. Because these expert reports do
not foreclose the likelihood that the blood from the blood
sample came exclusively from Johnson, they do not impeach
3670                  RICHTER v. HICKMAN
Johnson’s testimony that the blood came from him alone. The
expert reports also do nothing to contradict the weight of the
evidence presented at trial that supported the State’s theory of
the case.

                        3.   Pathology

   Appellants argue that their counsel rendered ineffective
assistance by failing to consult a pathology expert and present
testimony from such an expert at trial. Appellants argue that
a pathology expert could have determined whether Johnson’s
wounds were severe enough for Johnson to have been the
only source of the large pool of blood on the floor. Appellants
now proffer a declaration from a pathology expert stating that
“it is highly unlikely that the blood pool found in the doorway
between the bedroom and living room was caused by Mr.
Johnson’s wounds.” The expert’s rationale for this conclusion
is that Johnson was not bleeding enough, and did not remain
in the doorway long enough, to be the sole contributor to the
blood pool.

  [4] The lack of testimony from the pathology expert at trial
did not prejudice the appellants. The reasons the expert pro-
vided in reaching his conclusion are flawed and are partially
contradicted by the record.

   First, the expert states that it is unlikely that Johnson had
been bleeding significantly from his shoulder and cheek
wounds. The expert bases his conclusion upon the fact that
one of the policemen responding to Johnson’s 911 call “did
not notice that Mr. Johnson was injured until . . . several min-
utes after first contacting Mr. Johnson” inside the house. This
statement of fact, while technically correct, distorts the
record. The policeman in question, deputy Michael Wright
(“Wright”), testified that, immediately upon entering the
house, he noticed that Johnson had blood on him. Wright
stated that he noticed blood “on both [of Johnson’s] cheeks,
blood covering his shirt, . . . blood on his hands, and . . . on
                      RICHTER v. HICKMAN                    3671
his right shoulder.” Wright did not confirm that Johnson’s
blood came from Johnson’s own wounds until several minutes
later. It appears from Wright’s testimony that there was so
much blood on and around Johnson’s cheek that Wright did
not notice Johnson had been shot in the cheek until Johnson
wiped the blood off. Wright’s testimony contradicts, rather
than supports, the defense expert’s conclusion that Johnson
was not bleeding enough to be the sole contributor to the
blood pool.

   Second, the expert states that the amount of blood likely to
result from a shoulder wound would likely be minimal. This
statement fails to undermine the State’s case. The statement
does not address the quantity of blood that could be produced
by a bullet wound in the cheek. The statement is speculative,
and is contradicted by Wright’s eyewitness testimony at trial.

   [5] Third, the expert states that it is unlikely Johnson was
standing in the doorway long enough to create the pool of
blood. This observation adds little beyond what a lay jury is
qualified to observe. The expert does not provide any medical
or scientific basis for his conclusion. There is not a reasonable
probability that the expert’s testimony, based upon the same
observations that the jury was qualified to make, would have
affected the jury’s verdict.

    4.   Aggregate Impact of the Proffered Testimony

   [6] Strickland requires us to assess the aggregate impact of
counsel’s alleged failures when evaluating whether such
alleged failures prejudiced the defendants. 466 U.S. at 695-96.
The proffered testimony from the experts in firearms evi-
dence, serology and pathology, considered in the aggregate,
does not demonstrate prejudice. The testimony is not compel-
ling enough to conclude that there is a reasonable probability
that the jury would have reached a different verdict had they
heard the testimony.
3672                  RICHTER v. HICKMAN
                                B

   [7] Appellants next argue that their counsel rendered inef-
fective assistance by failing to consult and present an expert
on bloodstain pattern interpretation. We are unconvinced that
trial counsels’ failure to consult an expert on bloodstain pat-
tern interpretation falls outside the wide range of profession-
ally competent assistance. See Strickland, 466 U.S. at 690.
Before trial, it was not unreasonable for counsel to fail to
understand that an expert in bloodstain pattern interpretation
—someone who could testify as to “blood into blood pat-
terns” and “satellite drops” that result from blood falling from
a certain height—would be valuable to his case. Counsel
highly experienced in trying cases involving bloodstain evi-
dence might well have understood the value of such an expert,
but the Sixth Amendment does not guarantee defendants a
right to highly experienced counsel. See id. at 688, 690.

   Richter’s defense counsel, Mark Axup (“Axup”) stated that
he was surprised by the State’s decision at trial to call a detec-
tive as an expert on blood spatter evidence. The detective,
Robert Bell (“Bell”), had investigated the homicide of Klein.
Defense counsel had expected Bell to testify, but not as an
expert in bloodstain pattern interpretation. The State made a
last-minute decision to ask Bell to testify about the blood
spatter evidence.

   By the time Bell had testified, the trial was well underway
and Axup later stated that defense counsel had little to no time
to delve into the specifics of bloodstain pattern science. Given
the circumstances, it was reasonable for counsel to not spend
time attempting to locate and consult potential rebuttal
experts, particularly since it was not clear that such an expert
would disagree with the opinion of the State’s expert. Defense
counsel’s failure to call an expert on bloodstain pattern inter-
pretation did not fall below the low threshold of performance
required by Strickland.
                       RICHTER v. HICKMAN                     3673
                                C

   [8] Richter argues that Axup provided ineffective assis-
tance by failing to call several lay witnesses to testify at trial.
Richter argues that the testimony of these witnesses would
have supported Richter’s claim that Johnson’s gun safe was
legitimately in Richter’s residence at the time of the shoot-
ings. If the jury believed this claim, Richter and Branscombe
could not have entered Johnson’s house with the motive to
steal the safe.

   Axup called one witness at trial, Stephanie Edwards
(“Edwards”), to support Richter’s claim. Edwards testified
that she saw the gun safe inside Richter’s residence on several
occasions, including two days before the shootings. Johnson
testified at trial that he had kept his safe at Richter’s residence
for one or two weeks, but that he had moved the safe to his
house at the end of November or the beginning of December.
Scott Brown testified that he had helped Johnson move the
safe from Richter’s residence to Johnson’s house during the
first or second week of December.

   The district court found that Axup made a tactical decision
not to call the additional witnesses in question. This finding
is not clearly erroneous. Axup testified in his 2004 deposition
that he believed the State’s cross-examination of these addi-
tional witnesses would harm their credibility, and that calling
the witnesses would not be in the best interest of his client.
The fact that, nearly nine years after trial, Axup could not
recall the exact reasons why he believed that the witnesses
were not credible does not mean that Axup had no basis for
his decision at the time he made it. Axup had already called
one witness who testified that the safe was in Richter’s resi-
dence before the shootings. Axup’s tactical decision not to
call the other lay witnesses was not unreasonable. See Strick-
land, 466 U.S. at 690 (stating that strategic choices made by
counsel after thorough investigation are “virtually unchal-
lengeable”).
3674                  RICHTER v. HICKMAN
                               D

   [9] Richter argues that Axup provided ineffective assis-
tance of counsel by not investigating whether it was possible
to retrieve a fragment of floorboard with a bullet hole in it.
The floorboard came from Johnson’s bedroom. Johnson testi-
fied that he made the hole when he accidentally fired his .22
caliber firearm while cleaning it a couple of weeks before the
shootings. During trial, the prosecutor sent Investigator Brian
Maloney (“Maloney”) to investigate the bullet hole. Maloney
photographed the hole with a measuring device next to it, and
then cut out the piece of floorboard with the hole in it in an
attempt to find the bullet. The floorboard fell into the crawl
space beneath the house. Maloney testified at trial that the
crawl space was inaccessible, and therefore he could not
retrieve the floorboard. Maloney testified that he believed the
hole was consistent with the size of a .22 caliber bullet.

   After trial, Richter’s father discovered that the crawl space
was accessible. He retrieved the floorboard and gave it to
Axup, who gave it to a firearms evidence expert, James Aiello
(“Aiello”), for testing. Aiello determined that the hole was
probably caused by a .380 caliber firearm, rather than a .22
caliber. This conclusion, if known at trial, would have given
some support to the defense’s theory that Johnson fired the
.380 caliber Mac-12 at Branscombe on the night of the shoot-
ing. It also would have contradicted Johnson’s testimony that
he created the hole while cleaning his .22 caliber.

   Axup’s decision not to attempt to recover the floorboard
was reasonable given the circumstances. Maloney testified
under oath at trial that the floorboard was inaccessible, and
Axup had no reason to disbelieve him. Given Maloney’s testi-
mony that the hole was consistent in size with one created by
a .22 caliber bullet, Axup could reasonably believe that, even
were it possible to retrieve the floorboard, the evidence would
be inculpatory, not exculpatory. Further, Maloney did not cut
out the floorboard until a week after the start of trial. Consid-
                         RICHTER v. HICKMAN                         3675
ering the considerable time pressures during this trial and
Maloney’s testimony that the floorboard was inaccessible,
Axup’s decision not to search for the floorboard was reason-
able.

                                   IV

   Appellants argue that the prosecution suppressed exculpa-
tory evidence at trial in violation of Brady v. Maryland, 373
U.S. 83 (1963). Appellants allege that the Brady violation
occurred when Maloney lost the floorboard containing the
bullet hole in the crawl space and incorrectly testified that
there was no possible way to retrieve it.

   [10] It is well-established under Brady and its progeny that
the State violates due process when it suppresses or fails to
disclose material exculpatory evidence. See Illinois v. Fisher,
540 U.S. 544, 547 (2004); Brady, 373 U.S. at 87. The
Supreme Court limited Brady’s reach in California v. Trom-
betta, 467 U.S. 479 (1984) and Arizona v. Youngblood, 488
U.S. 51 (1988). Trombetta holds that, for the Brady standard
to apply, “evidence must . . . possess an exculpatory value
that was apparent before the evidence was destroyed.” 467
U.S. at 489 (emphasis added); see also Youngblood, 488 U.S.
at 56 n.*. Youngblood holds that the State’s failure to preserve
“potentially useful” evidence does not constitute a due pro-
cess violation unless the defendant can show bad faith on the
part of the police. 488 U.S. at 58; see also United States v.
Estrada, 453 F.3d 1208, 1212 (9th Cir. 2006) (drawing a dis-
tinction between “potentially exculpatory” and “apparently
exculpatory” evidence).

  Trombetta and Youngblood both involve evidence that the
police permanently lost or destroyed before its inculpatory or
exculpatory value could be conclusively determined. In both
cases, the police had no reason to believe that the evidence
would be exculpatory at the time the evidence was destroyed.2
  2
    In Trombetta, the Supreme Court determined that the State did not vio-
late due process when it failed to preserve samples of respondents’ breath
3676                      RICHTER v. HICKMAN
Here, similar to Trombetta and Youngblood, Maloney and the
prosecutor did not believe that the floorboard would be excul-
patory evidence at the time that it fell into the crawl space
beneath the house. In contrast to Trombetta and Youngblood,
however, the evidence at issue here was recovered after trial
and was found to have exculpatory value.

   [11] We have not yet specifically addressed whether the
rules announced by the Supreme Court in Trombetta and
Youngblood apply in the unusual factual situation presented
here. By their own terms, Trombetta and Youngblood apply in
situations where, as here, the police did not believe evidence
to have exculpatory value when it was lost or misplaced, even
if the evidence is later recovered and determined to be excul-
patory.

   [12] The Supreme Court made clear in Trombetta and
Youngblood that the dispositive issue for due process pur-
poses is the state of mind of police or prosecutors at the time
the evidence is lost or destroyed. See Youngblood, 488 U.S.
at 56 n.*; Trombetta, 467 U.S. at 488-89.3 The Supreme Court

in cases where respondents were convicted of drunk driving. 467 U.S. at
491. The respondents claimed that, had the breath samples been preserved,
they would have been able to impeach the incriminating test results. Id. at
483. The Court held in Youngblood that the failure of the police to pre-
serve semen on clothing that could have potentially exculpated the defen-
dant of sexual assault charges did not violate due process. 488 U.S. at 58.
The defendant alleged that he had been misidentified as the perpetrator. Id.
at 54. The Court held that, absent a showing of bad faith, police do not
violate due process when they fail to disclose or preserve “evidentiary
material of which no more can be said than that it could have been sub-
jected to tests, the results of which might have exonerated the defendant.”
Id. at 57.
   3
     In Youngblood, for example, the Supreme Court focused specifically
on the police officers’ state of mind at the time the evidence was lost:
“Here, respondent has not shown that the police knew the semen samples
would have exculpated him when they failed to . . . refrigerate the boy’s
clothing; this evidence was simply an avenue of investigation that might
have led in any number of directions.” 488 U.S. at 56 n.* (emphasis
added).
                      RICHTER v. HICKMAN                    3677
reached this conclusion based upon their stated “unwilling-
ness to read the . . . Due Process Clause as imposing on the
police an undifferentiated and absolute duty to retain and to
preserve all material that might be of conceivable evidentiary
significance in a particular prosecution.” Youngblood, 488
U.S. at 58 (citation omitted). The Supreme Court did not
approve a constitutional standard where acceptable manage-
ment of evidence by law enforcement could retroactively be
found unconstitutional if, after trial and conviction, a defen-
dant shows that the evidence would have been exculpatory.
The post-trial retrieval of the floorboard does not entitle
appellants to a retroactive determination that Maloney vio-
lated appellants’ due process rights by inadvertently losing or
misplacing the evidence.

   [13] Applying the Trombetta-Youngblood rule here, we
find no evidence in the record of bad faith on the part of
Maloney or the prosecution. Maloney testified that he
believed the floorboard to be in an inaccessible location after
he cut it out of the floor in Johnson’s residence. The prosecu-
tion fully disclosed the nature and location of the evidence. At
worst, Maloney’s actions could be described as negligent.
Appellants were not denied due process of law, and the state
court’s denial of habeas relief on this ground was not an
unreasonable application of federal law.

                               V

   [14] Branscombe argues that his trial counsel, Thomas
Dixon (“Dixon”), failed to subject the prosecution’s case to
meaningful adversarial testing in violation of United States v.
Cronic, 466 U.S. 648 (1984). In Cronic, the Supreme Court
identified three situations where the Court does not require a
showing of prejudice to establish a violation of the Sixth
Amendment right to counsel. See id. at 658-61. These situa-
tions include (1) where there has been a complete denial of
counsel at a critical stage of trial, (2) where counsel “entirely
fails to subject the prosecution’s case to meaningful adver-
3678                     RICHTER v. HICKMAN
sarial testing” and (3) where “surrounding circumstances
made it . . . unlikely that any lawyer could provide effective
assistance.” Id. at 659-61. The Supreme Court later empha-
sized that Cronic’s exception for failing to test the prosecu-
tion’s case applies only when the attorney’s failure to do so
is complete. Bell v. Cone, 535 U.S. 685, 697 (2002). An attor-
ney’s failure to oppose the prosecution at specific points dur-
ing the trial does not rise to the level of a Cronic violation.
See id. Rather, the attorney’s failure must implicate the pro-
ceeding as a whole. United States v. Thomas, 417 F.3d 1053,
1057 (9th Cir. 2005) (citing Bell, 535 U.S. at 697).

   [15] Branscombe argues that Dixon’s lack of investigation
and preparation for trial resulted in a failure to subject the
prosecution’s case to meaningful adversarial testing. We are
not persuaded that Dixon’s lackluster preparation for trial
resulted in a complete failure to contest the prosecution’s
case. To the contrary, the record shows that Dixon engaged in
adversarial testing on numerous occasions throughout trial. As
the district court and the state appellate court noted, Dixon
cross examined most of the witnesses, successfully moved to
suppress statements and strike testimony, successfully moved
to exclude evidence and had a witness perform a demonstra-
tion. Dixon also asked several questions of Richter at trial to
support the theory that Branscombe had returned to Johnson’s
house to give Johnson a firearm, and had fired the weapon in
self-defense. Dixon’s participation at trial demonstrates that
he did not entirely fail to subject the prosecution’s case to
meaningful adversarial testing.4
  4
   We agree with the State that Branscombe’s Cronic claim is unex-
hausted. Branscombe did not present to the California state courts the
“substantial equivalent” of the claim presented in federal court. Lopez v.
Schriro, 491 F.3d 1029, 1040 (9th Cir. 2007). The factual basis for Bran-
scombe’s current Cronic claim rests primairly upon new evidence that the
California state courts did not have the opportunity to consider on direct
review. The State did not expressly waive its exhaustion defense before
the district court. The State may therefore raise the defense here, even
                         RICHTER v. HICKMAN                        3679
                                  VI

   Richter alleges that the trial court violated his Eighth and
Fourteenth Amendment rights by providing an incorrect or
inaccurate answer to a request for clarification that the jury
submitted to the trial court during deliberations. The jury
requested the following clarification from the trial court: “If
a defendant is found to have aided & abetted in [robbery], is
he guilty of all charges (or can you find him guilty of lesser
charges) as found for the other defendant.” The trial court
responded “yes” (i.e., that the defendant is guilty of all
charges), over defense counsel’s objections. Richter argues
that this response was an incorrect statement of California
law, that this error violated Richter’s rights to a jury trial and
to due process of law and that a writ of habeas corpus must
issue as a result.

   To obtain habeas relief following an erroneous response to
a jury’s request for clarification, a petitioner must show that
(1) the response was an incorrect or inaccurate application of
state law, (2) constitutional error resulted and (3) the error
was not harmless. See Morris v. Woodford, 273 F.3d 826, 833
(9th Cir. 2001). To determine whether constitutional error
occurred, we ask “whether there is a reasonable likelihood
that the jury has applied the challenged instruction in a way
that violates the Constitution.” Estelle v. McGuire, 502 U.S.
62, 72 (1991) (internal quotations and citation omitted). In
other words, constitutional error occurs when (1) there is a
reasonable likelihood that the jury understood the trial judge’s
response to a request for clarification as stating a certain rule
of law, (2) that rule, as potentially understood by the jury, was

though the district court did not address the exhaustion issue. See 28
U.S.C. § 2254(b)(3). We deny Branscombe’s unexhausted petition on the
merits. See 28 U.S.C. § 2254(b)(2). For the reasons stated above, we find
it perfectly clear that Branscombe does not raise even a colorable Cronic
claim. See Cassett v. Stewart, 406 F.3d 614, 623-24 (9th Cir. 2005).
3680                  RICHTER v. HICKMAN
incorrect or inaccurate and (3) the rule, so understood, was
unconstitutional as applied to the defendant. See Calderon v.
Coleman, 525 U.S. 141, 147 (1998). In attempting to deter-
mine what the jury understood the response to mean, the
response “may not be judged in artificial isolation, but must
be considered in the context of the instructions as a whole and
the trial record.” Estelle, 502 U.S. at 72 (internal quotations
and citation omitted).

   To determine whether the error was harmless, we consider
whether the error had a “substantial and injurious effect or
influence on the jury’s verdict.” Calderon, 525 U.S. at 147.
“If we are in grave doubt as to whether the error had such an
effect, the petitioner is entitled to the writ.” Morris v. Wood-
ford, 273 F.3d 826, 833 (9th Cir. 2001) (internal quotations
and citation omitted).

   [16] The trial court’s response to the jury’s request for clar-
ification could be interpreted as an inaccurate statement of
California law. The jury’s request and the trial court’s answer
(referred to hereafter as the “colloquy”) created an ambiguity.
The most natural reading of the colloquy is that it correctly
states California’s felony murder rule: when a defendant aids
and abets a robbery, and someone is killed during the robbery,
the defendant is guilty of both robbery and murder, even if his
accomplice does the killing. See People v. Washington, 402
P.2d 130, 134 (Cal. 1965). But the colloquy goes further. It
permits the jury to conclude that a defendant who aids and
abets a robbery-murder must be found guilty of robbery and
murder even if he does not begin to aid or abet the robbery
until after the murder has already occurred. This interpretation
of the colloquy results in an incorrect statement of California
law. California permits a defendant who aids and abets a rob-
bery to be found guilty of felony murder only if he began his
aiding and abetting before the commission of the killing. See
People v. Pulido, 936 P.2d 1235, 1236 (Cal. 1997).

  [17] Constitutional error did not result because it is not rea-
sonably likely that the jury interpreted the colloquy in a man-
                      RICHTER v. HICKMAN                   3681
ner that misstates the law. In phrasing the request for
clarification the way they did, it is unlikely that the jury was
attempting to determine whether someone who began to aid
and abet a robbery only after a murder had been committed
must be found guilty of the murder. If the jury were intending
to pose such a question to the judge, they likely would have
done so in a more direct manner. The manner in which the
question was phrased strongly suggests that the jury was ask-
ing for a clarification of the felony murder rule for accom-
plices, as described above. Given the question that the jury
was posing to the trial judge, it is not reasonably likely that
the jury understood the response to mean anything more than
a straightforward and accurate statement of California’s fel-
ony murder rule.

   Even if the trial court did commit constitutional error, the
error was harmless. For the error to have an injurious effect
or influence in determining the jury’s verdict, the jury must
have believed that Branscombe committed robbery and mur-
dered Klein, but that Richter did not begin to aid or abet the
robbery until after the murder occurred. To believe this, the
jury would have to have found, based on the facts presented
to them at trial, that (1) Richter had no intention of robbing
Johnson (or of helping Branscombe rob Johnson) when he
and Branscombe drove to Johnson’s house around 4:00 that
morning, (2) Branscombe, unbeknownst to Richter, decided to
rob Johnson and shoot Klein, (3) after Klein was shot, Richter
decided to aid and abet Branscombe in committing the rob-
bery. Neither the State nor the defendants argued such a the-
ory of the case. Such a conclusion would go against
significant evidence presented at trial, including the evidence
showing that Richter owned the same type of bullets used to
shoot Klein. This conclusion would also be inconsistent with
the testimony of both Richter and Johnson. It is unlikely that
any member of the jury arrived at this conclusion.

   [18] Because the trial court did not commit constitutional
error, and because any error would have been harmless, Rich-
ter is not entitled to a writ of habeas corpus on this claim.
3682                RICHTER v. HICKMAN
                            VII

  We affirm the district court’s denial of Richter and Bran-
scombe’s petitions for writs of habeas corpus.

  AFFIRMED.
