               FOR PUBLICATION

  UNITED STATES COURT OF APPEALS
       FOR THE NINTH CIRCUIT


ALAN G. GIMENEZ,                         No. 14-55681
             Petitioner-Appellant,
                                            D.C. No.
                v.                       3:12-cv-01137-
                                           LAB-BLM
J.T. OCHOA, Warden; KAMALA D.
HARRIS, Attorney General,
            Respondents-Appellees.         OPINION


     Appeal from the United States District Court
       for the Southern District of California
      Larry A. Burns, District Judge, Presiding

               Argued and Submitted
       October 22, 2015—Pasadena, California

                     Filed May 9, 2016

        Before: Alex Kozinski, Sandra S. Ikuta
         and John B. Owens, Circuit Judges.

             Opinion by Judge Kozinski
2                       GIMENEZ V. OCHOA

                           SUMMARY*


                          Habeas Corpus

   The panel affirmed the district court’s dismissal of Alan
Gimenez’s second habeas corpus petition challenging his
conviction for the second degree murder of his infant
daughter based on the prosecution’s theory that his daughter
was a victim of shaken baby syndrome.

    The panel held that Gimenez’s ineffective assistance of
counsel claim, which concerns errors primarily related to the
use of expert testimony, is barred as successive because his
arguments don’t present a claim for relief that is distinct from
the claim raised in his first petition.

    The panel held that Gimenez can’t obtain relief under
28 U.S.C. § 2244(b)(2)(B)(ii) on the theory that the
prosecution introduced false testimony by incorrectly
interpreting key hospital records in violation of his due
process rights, where Gimenez simply presents a battle
between experts who have different opinions about how his
daughter died. The panel held that the district court properly
found that he didn’t demonstrate the requisite “constitutional
error” under § 2244(b)(2)(B)(ii).

    Gimenez also argued that new scientific evidence
undermines the prosecution’s theory that his daughter was a
victim of shaken baby syndrome and thus shows that he’s
actually innocent of her murder. The panel held that habeas

  *
    This summary constitutes no part of the opinion of the court. It has
been prepared by court staff for the convenience of the reader.
                     GIMENEZ V. OCHOA                        3

petitioners can allege a constitutional violation from the
introduction of flawed expert testimony at trial if they show
that the introduction of this evidence undermined the
fundamental fairness of the entire trial. The panel concluded
that Gimenez isn’t entitled to relief. The panel explained that
Gimenez failed to show that permitting the prosecution’s
experts to testify based on a triad-only theory of shaken baby
syndrome was so extremely unfair that it violated
fundamental conceptions of justice, and that he presented
literature revealing not so much a repudiation of triad-only
shaken baby syndrome, but a vigorous debate about its
validity within the scientific community.

    The panel wrote that Gimenez could not obtain relief if
the panel were to decouple his claim of actual innocence from
any due process violation and repackage it as a freestanding
“actual innocence” claim. The panel noted that this court has
only assumed, but not held, that petitioners may bring such a
freestanding innocence claim. The panel explained that
Gimenez’s “new” evidence doesn’t undermine the
prosecution’s case so much as beef up the theory that the jury
already rejected: that his daughter suffered from health
problems at birth that caused her subdural hematoma, brain
swelling, retinal hemorrhage and eventually her death.
4                   GIMENEZ V. OCHOA

                        COUNSEL

George L. Schraer (argued), San Diego, California, for
Petitioner-Appellant.

Kevin Vienna (argued), Supervising Deputy Attorney
General; Julie L. Garland, Senior Assistant Attorney General;
Gerald A. Engler, Chief Assistant Attorney General; Kamala
D. Harris, Attorney General, San Diego, California, for
Respondents-Appellees.


                        OPINION

KOZINSKI, Circuit Judge:

    Two decades after being convicted of murdering his
infant daughter, Alan Gimenez seeks federal habeas relief for
the second time. We consider whether Gimenez’s ineffective
assistance of counsel claims are barred as successive. We
also consider whether he may advance a due process claim on
the ground that expert evidence presented at trial has been
undermined by subsequent scientific developments.

                      I. Background

                   A. Medical History

    Gimenez’s daughter, Priscilla, was seven weeks old when
she died. During her short life, she vomited on multiple
occasions after being fed. She also had seizures. On one
occasion when Gimenez was at home alone with Priscilla, he
saw her shaking and having difficulty breathing. Gimenez
performed CPR and called 911. Paramedics took Priscilla to
                        GIMENEZ V. OCHOA                                5

the hospital, where she stayed for three days; she was
diagnosed with epilepsy.

    Hours after Priscilla was discharged, Gimenez’s wife,
Teresa, left for work and Gimenez fed Priscilla. Almost
immediately, Priscilla vomited forcefully and experienced
another seizure. Gimenez administered medicine as he was
instructed by Priscilla’s doctors and called Teresa. The
couple rushed back to the hospital with Priscilla, where they
remained for three days until her death. Gimenez was
charged with her murder.

                               B. Trial

    Gimenez and the government offered competing
narratives at trial. The prosecution theorized that Gimenez
had caused Priscilla’s death by forcefully shaking her on at
least two occasions. The defense argued that Priscilla was a
sickly baby with birth injuries that worsened over time and
eventually killed her.

    Prosecution witnesses testified that Priscilla experienced
a fairly normal birth, did not have a misshapen head, fed well
and displayed normal vital signs in the days after she was
born. Pediatrician Dr. Gooding testified that she discovered
a suspicious fresh tear of Priscilla’s frenulum1 when she
examined Priscilla upon her first hospital visit. Dr. Gooding
commented that the injury usually results from “fairly
vigorous trauma to the oral cavity.” At the hospital, Gimenez
accused an emergency-room doctor of tearing Priscilla’s
frenulum during an examination, but at trial he testified that

 1
   The frenulum is the tissue underneath the tongue that anchors it to the
mouth.
6                    GIMENEZ V. OCHOA

he’d inadvertently caused the injury while cleaning Priscilla’s
mouth. The jury also heard that Gimenez accused Teresa of
infidelity, slapped her and pushed her during an argument late
in her pregnancy, causing her to fall.

    Experts provided the linchpin for the prosecution’s theory
that Priscilla was a victim of shaken baby syndrome (SBS).
Radiologist Dr. Hilton analyzed x-rays of Priscilla’s ribs and
concluded that she was born without any bone damage but
had a rib fracture at the time of her death. Coroner Dr. Eisele
estimated that the rib fracture was about two weeks old when
Priscilla died. He also testified that Priscilla had a subdural
hematoma, or hemorrhage between the lining of her skull and
the surface of the brain. Dr. Eisele also observed
hemorrhaging in Priscilla’s retinas and that her brain was
“severely swollen.” He concluded that Priscilla had been
shaken.

   Pediatrician Dr. Alexander testified that the hallmarks of
SBS include subdural hematoma, brain swelling and retinal
hemorrhage. He also noted that rib fractures are extremely
uncommon in infants. He attributed Priscilla’s two hospital
admissions to separate shaking episodes.

    Gimenez’s experts countered with evidence that Priscilla
was born with serious ailments that ultimately caused her
death. Obstetrician Dr. Kerley testified that Teresa needed a
C-section because she was in labor for more than 24 hours
without achieving full dilation. He opined that the prolonged
pressure of the narrow pelvic canal on Priscilla’s skull may
have caused molding or deformation of Priscilla’s head.

    Forensic pathologist Dr. Guard concluded that Teresa’s
strenuous labor caused Priscilla’s subdural hemorrhage,
                     GIMENEZ V. OCHOA                        7

pointing to doctors’ notes from the delivery room
documenting molding in Priscilla’s head. He explained that
Priscilla’s hemorrhage likely clotted, healed and re-bled in an
uncontrollable “chain reaction” in the weeks following her
birth, causing brain swelling and retinal hemorrhages. He
explained that Priscilla’s vomiting and seizures were an
expected outward manifestation of re-bleeding as her brain
healed. Finally, Dr. Guard attributed Priscilla’s broken rib to
physicians grasping her firmly while lifting her from the
uterus during the C-section.

    Neurologist Dr. Tiznado-Garcia analyzed Priscilla’s
hospital records and CT scans and concluded that she died
from complications caused by a brain bleed that began at
birth. Dr. Tiznado-Garcia ruled out SBS as a cause,
explaining that brain bleeds caused by shaking are acute,
while Priscilla’s was chronic. Radiologist Dr. Harvey,
however, conceded on cross-examination that Priscilla’s
injuries were consistent with non-accidental trauma.

     The jury found Gimenez guilty of murder in the second
degree. He was sentenced to an indeterminate prison term of
fifteen years to life.

             C. Previous Habeas Proceedings

    In his first federal habeas petition, Gimenez alleged that
his trial counsel was ineffective for failing to gather
Priscilla’s entire medical record. The missing documents
suggested that Priscilla suffered from a congenital blood
disorder with effects that mimic those of SBS. He also
claimed that his counsel was ineffective by failing to consult
a hematologist or question the experts he did retain about
whether Priscilla had a blood disorder.
8                        GIMENEZ V. OCHOA

    The district court determined that Gimenez suffered no
prejudice from any deficient use of expert testimony or
failure to obtain medical records: The prosecution’s case
would have been just as strong, and the evidence wouldn’t
have enabled the defense to overcome Gimenez’s credibility
problems. We affirmed in a memorandum disposition.
Gimenez v. Alameida, 135 F. App’x 20 (9th Cir. 2005).

    In 2009, Gimenez filed a habeas petition in the Superior
Court of California nearly identical to the federal petition at
the heart of this case, which the California courts denied.
Gimenez then filed a second federal habeas petition with this
court’s permission. The district court granted the state’s
motion to dismiss, which Gimenez appeals.

                            II. Discussion

    Gimenez’s second federal habeas petition presents three
grounds for relief: (1) his counsel rendered ineffective
assistance; (2) he was convicted based on false expert
testimony; and (3) his due process rights were violated when
he was convicted based on flawed scientific evidence even
though he was innocent. Gimenez must clear the high
hurdles erected by 28 U.S.C. § 2244(b) for obtaining relief on
any of these grounds.

                A. Ineffective Assistance Claim

    Gimenez’s ineffective assistance claim concerns errors
primarily related to the use of expert testimony.2 We must


    2
      Specifically, Gimenez claims that his attorney rendered deficient
performance eight ways by: (1) hiring an incompetent pathologist, Dr.
Guard, to testify that Priscilla suffered from a recurring brain bleed that
                           GIMENEZ V. OCHOA                                    9

dismiss this claim if it is identical to the one raised in his first
habeas petition—that is, if the two share the same “legal basis
for granting . . . relief.” Sanders v. United States, 373 U.S. 1,
14–16 (1963); see 28 U.S.C. § 2244(b)(1).

    The standard for “distinguishing repetitious claims from
new ones is the ‘substantial similarity’ rule” used to
determine whether a claim has been exhausted in state court.
See Randy Hertz & James S. Liebman, 2 Federal Habeas
Corpus Practice & Procedure § 28.1 n.8 (6th ed. 2011).
Under the exhaustion test, a petitioner can introduce
additional facts to support a claim on federal habeas review
so long as he presented the “substance” of the claim to the
state courts. Vasquez v. Hillery, 474 U.S. 254, 257–58
(1986). That the additional facts provide more sophisticated
or reliable support is of no moment where the information
does not “fundamentally alter the legal claim already
considered.” Id. at 260. A claim in a successive petition is
barred when its “basic thrust or gravamen” is the same as a
claim that’s already been raised, even if it’s supported by new
factual allegations or legal arguments. Babbitt v. Woodford,
177 F.3d 744, 746 (9th Cir. 1999) (quoting United States v.



began at birth; (2) failing to call a radiologist to testify that Priscilla’s rib
fracture appeared at birth and that her brain bleed began before her final
hospital stay; (3) hiring radiologist Dr. Harvey, who admitted that
Priscilla’s brain bleeds were consistent with an SBS theory; (4) suffering
neurologist Dr. Tiznado-Garcia to testify that Priscilla’s CT scans revealed
an older, recurring brain bleed instead of employing a radiologist to do so;
(5) not relying on experts more qualified than Dr. Guard and Dr. Tiznado-
Garcia to present the alternate theory of Priscilla’s death; (6) failing to
subpoena Priscilla’s complete medical records and provide them to
defense experts; (7) failing to better prepare Dr. Kerley to testify that
Priscilla’s head underwent “molding”; and (8) not bolstering the
alternative theory of Priscilla’s death with available medical records.
10                   GIMENEZ V. OCHOA

Allen, 157 F.3d 661, 664 (9th Cir. 1998)); accord
Gulbrandson v. Ryan, 738 F.3d 976, 997 (9th Cir. 2013).

    Our cases characterize ineffective assistance “claims” at
a fairly high level of generality. In West v. Ryan, we equated
an allegation that counsel failed to present mitigation
evidence with an allegation that counsel failed to invalidate
petitioner’s aggravating factors by presenting the same
evidence. 652 F.3d 1071, 1077 (9th Cir. 2011). And in
Cooper v. Brown, an ineffective assistance claim based on
counsel’s failure to introduce photographs of hair was barred
where the district court already considered counsel’s
deficiencies in utilizing forensic evidence. 510 F.3d 870,
874, 930–31 (9th Cir. 2007).

     Gimenez essentially concedes that he previously raised at
least one argument: Trial counsel was ineffective for “failing
to subpoena all of Priscilla’s medical records and provide
them to the defense’s expert witnesses.” Gimenez maintained
in his first petition that his case would have been stronger if
trial counsel had reviewed, “with the assistance of appropriate
medical experts, all medical records.” It makes no difference
that Gimenez may now have additional documents supporting
his argument that counsel was deficient in failing to locate all
of Priscilla’s records. The “basic thrust or gravamen” is the
same. Gulbrandson, 738 F.3d at 997; see also Cooper,
510 F.3d at 931.

     Nor can Gimenez succeed by faulting his counsel for
failing to use all available medical evidence. Any criticism
of counsel’s failure to obtain complete records would be
meaningless if counsel weren’t expected to employ favorable
undiscovered evidence in support of his case. These
                      GIMENEZ V. OCHOA                         11

arguments are “two sides of the same coin.” West, 652 F.3d
at 1077.

     Gimenez’s six remaining arguments echo the same
grounds for relief he presented to the district court in his first
habeas petition: Counsel should have used better experts. In
disposing of his first petition, the district court considered
whether trial counsel was deficient for failing to consult the
proper experts to “present a different, more effective
defense.” This time around, Gimenez explains in more detail
why different experts would have improved his case. But a
federal court already denied relief after considering whether
Gimenez suffered prejudice from the failure to present
adequate expert evidence in support of the defense’s theory
of the case. Because the impact of counsel’s deficiencies in
utilizing experts “has already been adjudicated,” Gimenez’s
new arguments don’t present a distinct claim for relief.
Cooper, 510 F.3d at 988.

  B. Due Process Challenge Based on False Testimony

    Gimenez argues that the prosecution’s experts incorrectly
interpreted key hospital records and thus offered false
testimony at trial, violating his due process rights.
Accordingly, Gimenez claims that he alleged the requisite
constitutional error that would entitle him to proceed on his
claim under 28 U.S.C. § 2244(b)(2)(B)(ii). That section
permits relief to petitioners who can show by “clear and
convincing evidence that, but for constitutional error, no
reasonable factfinder would have found [them] guilty.”

    To dismiss a second or successive petition, a district court
must determine that the record “conclusively shows” that the
petitioner failed to meet section 2244’s requirements. United
12                       GIMENEZ V. OCHOA

States v. Villa-Gonzalez, 208 F.3d 1160, 1164–65 (9th Cir.
2000). After conducting a thorough review of Gimenez’s
new petition, the district court properly found that he didn’t
demonstrate “constitutional error” under section
2244(b)(2)(B)(ii) from the introduction of false testimony.
Gimenez presents affidavits from new experts that either
repeat testimony from his trial experts or fail to contradict the
prosecution’s theory.3 To the extent that this new testimony


  3
       First, Gimenez claims that the prosecution’s experts erroneously
determined that Priscilla’s brain bleeds occurred just before her death.
New experts Dr. Wolfe and Dr. Plunkett provide affidavits
concluding—just like Dr. Tiznado-Garcia did at trial—that Priscilla’s
brain bleed was chronic and began soon after her birth. Second, Gimenez
presents affidavits from multiple experts who conclude that Priscilla had
a blood clot that formed before her death—just like Dr. Tiznado-Garcia
testified at trial. Third, Gimenez presents affidavits from two experts who
believe that Priscilla’s retinal hemorrhages were no more than 72 hours
old. Thus, they may have formed during her final hospital stay from
August 10 to August 13—not as a result of any shaking incidents when
she was alone with Gimenez on August 10. This evidence is consistent
with the prosecution’s theory that Priscilla was violently shaken on the
afternoon she returned to the hospital—three days before her death.
Fourth, Gimenez claims that two new experts conclude that Priscilla
suffered from a blood coagulation disorder which led to her death.
However, one of the experts notes that “head trauma in and of itself” may
result in abnormal coagulation patterns, “rendering it virtually impossible”
to determine which came first, as “appears to be the case [here].” And the
other expert found “no medical records to indicate” blood disorders.
These findings are also consistent with the prosecution’s theory of the
case. Fifth, Gimenez introduces an affidavit from a radiologist who
concludes, based on an x-ray taken immediately after Priscilla’s birth, that
she likely had a rib fracture at that time. This testimony supports that of
defense expert Dr. Guard, who testified that doctors likely broke
Priscilla’s rib by accident during her birth. Sixth, Gimenez points to
additional medical records documenting Priscilla’s head “molding” during
her traumatic birth. This merely amplifies the testimony of defense
experts Dr. Kerley and Dr. Guard at trial. Finally, Gimenez points to a
                        GIMENEZ V. OCHOA                              13

contradicts the prosecution’s expert testimony, it’s simply a
difference in opinion—not false testimony. See, e.g., United
States v. Workinger, 90 F.3d 1409, 1416 (9th Cir. 1996);
Harris v. Vasquez, 949 F.2d 1497, 1524 (9th Cir. 1991) (as
amended); cf. Sistrunk v. Armenakis, 292 F.3d 669, 675 & n.7
(9th Cir. 2002) (en banc) (overstating the conclusions of a
study was not a lie). We have found due process violations
from the introduction of false testimony only where a fact
witness told lies (even unknowingly so) or the prosecution
relied on phony documents. See, e.g., Phillips v. Ornoski,
673 F.3d 1168, 1183–86 (9th Cir. 2012); Maxwell v. Roe,
628 F.3d 486, 506 (9th Cir. 2010); Hall v. Dir. of Corr.,
343 F.3d 976, 981–85 (9th Cir. 2003). Neither is the case
here.

    Gimenez presents a battle between experts who have
different opinions about how Priscilla died. Introducing
expert testimony that is contradicted by other experts,
whether at trial or at a later date, doesn’t amount to suborning
perjury or falsifying documents; it’s standard litigation.
Accordingly, Gimenez can’t obtain relief under section
2244(b)(2)(B)(ii) on the theory that the prosecution
introduced false testimony at trial.

 C. Claims Based on Changes in Scientific Knowledge

   Finally, Gimenez argues that new scientific evidence
undermines the prosecution’s theory that Priscilla was a


recent publication suggesting that patterns of hemorrhage from accidental
trauma “may be the same as . . . or completely different from the pattern
seen in [abusive head trauma].” That statement is not inconsistent with
the prosecution’s theory that the patterns of hemorrhage were attributable
to SBS.
14                  GIMENEZ V. OCHOA

victim of SBS and thus shows that he’s actually innocent of
her murder. Gimenez claims that the prosecution’s experts
rested their SBS diagnosis on a triad of symptoms—subdural
hematoma, brain swelling and retinal hemorrhage. He points
to a number of articles supporting his claim that medical
knowledge surrounding SBS has changed in the years since
his conviction. In his view, no longer do forensic
pathologists diagnose SBS simply by noting the presence of
the telltale triad of injuries. Now, the medical community
requires evidence of impact injuries before diagnosing SBS.
Because Priscilla didn’t exhibit head or neck injuries,
Gimenez argues that she couldn’t have been the victim of
SBS.

    Based on this new evidence, Gimenez argues that he’s
entitled to bring a claim under section 2244(b)(2)(B)(ii) and
under caselaw permitting habeas relief for petitioners who are
actually innocent of any crime.

        1. Relief Under Section 2244(b)(2)(B)(ii)

    Gimenez argues that if his new evidence is credited, “no
reasonable factfinder” could have found him guilty.
28 U.S.C. § 2244(b)(2)(B)(ii). But section 2244(b)(2)(B)(ii)
also requires petitioners to state a predicate “constitutional
error.” See Case v. Hatch, 731 F.3d 1015, 1032 (10th Cir.
2013); In re Davis, 565 F.3d 810, 823 (11th Cir. 2009). The
Supreme Court has never recognized “actual innocence” as a
constitutional error that would provide grounds for relief
without an independent constitutional violation. See Schlup
v. Delo, 513 U.S. 298, 315–16 (1995); Herrera v. Collins,
506 U.S. 390, 400 (1993).
                        GIMENEZ V. OCHOA                              15

    Gimenez maintains that he did suffer the required
predicate constitutional error: The prosecution deprived him
of due process by introducing expert testimony about the
discredited triad theory of SBS. The district court couldn’t
find any authority for the proposition that “a conviction based
on the most up-to-date knowledge in the past transforms to a
violation of due process when that knowledge is modified in
ensuing years.” But courts have long considered arguments
that the introduction of faulty evidence violates a petitioner’s
due process right to a fundamentally fair trial—even if that
evidence does not specifically qualify as “false testimony.”
See Estelle v. McGuire, 502 U.S. 62, 68–70 (1991); Dowling
v. United States, 493 U.S. 342, 352–53 (1990); McKinney v.
Rees, 993 F.2d 1378, 1385 (9th Cir. 1993); Kealohapauole v.
Shimoda, 800 F.2d 1463, 1465–66 (9th Cir. 1986).

    Nothing compels a different rule for a challenge brought
in a successive petition to expert testimony about discredited
forensic principles or other junk science. Indeed, recognizing
such a claim is essential in an age where forensics that were
once considered unassailable are subject to serious doubt.4

 4
     In 2009, the National Research Council submitted a comprehensive
report to the U.S. Department of Justice critiquing the state of forensic
science. See Committee on Identifying the Needs of the Forensic Sciences
Community, National Research Council, Strengthening Forensic Science
in the United States: A Path Forward 57 (2009), available at
https://www.ncjrs.gov/pdffiles1/nij/grants/228091.pdf (“In some cases,
substantive information and testimony based on faulty forensic science
analyses may have contributed to wrongful convictions of innocent
people.”). The popular press and legal academia have regularly reported
research breakthroughs debunking or seriously undermining forensics
disciplines once thought to be scientifically sound. See, e.g., Brandon L.
Garrett & Peter J. Neufeld, Invalid Forensic Science Testimony &
Wrongful Convictions, 95 Va. L. Rev. 1 (2009) (reviewing trial records to
determine the incidence of experts overstating the probative value of
16                       GIMENEZ V. OCHOA

And it’s particularly important to permit claims of
constitutional error grounded in faulty science in a second or
successive petition. After all, flawed analytical methods may
not be debunked until well after the expiration of a


various forensic disciplines); Jennifer L. Mnookin, The Validity of Latent
Fingerprint Identification: Confessions of a Fingerprinting Moderate, 7
Law, Probability & Risk 127 (2008); Kelly Servick, Reversing the Legacy
of Junk Science in the Courtroom, Science (Mar. 7, 2016),
http://www.sciencemag.org/news/2016/03/reversing-legacy-junk-science-
courtroom (hair analysis, bite mark analysis, fingerprint comparisons);
NPR Staff, Arson Forensics Sets Old Fire Myths Ablaze, National Public
Radio (Nov. 19, 2011), http://www.npr.org/2011/11/19/142546979/arson-
forensics-sets-old-fire-myths-ablaze (arson and burn pattern analysis);
John Solomon, FBI’s Forensic Test Full of Holes, Wash. Post (Nov. 18,
2007), http://www.washingtonpost.com/wp-dyn/content/article/2007/
11/17/AR2007111701681_pf.html (comparative bullet-lead analysis).
Other sub-fields have been roundly criticized for relying on questionable
methodology or for overstating the probative value of forensic analysis.
Michael Hall, False Impressions, Tex. Monthly (Jan. 2016),
http://www.texasmonthly.com/articles/false-impressions/ (bite mark
analysis); Spencer S. Hsu, Va. Exoneration Underscores Mounting
Challenges to Bite-Mark Evidence, Wash. Post (Apr. 8, 2016),
https://www.washingtonpost.com/local/public-safety/va-exoneration-
underscores-to-mounting-challenges-to-bite-mar k-evidence/
2016/04/08/55bbfe98-fd9a-11e5-886f-a037dba38301_story.html
(reporting the exoneration of a sailor convicted of rape and murder based
on bite-mark analysis); Spencer S. Hsu, FBI Admits Flaws in Hair
Analysis Over Decades, Wash. Post (Apr. 18, 2015),
https://www.washingtonpost.com/local/crime/fbi-overstated-forensic-hair-
matches-in-nearly-all-criminal-trials-for-decades/2015/04/18/39c8d8c6-
e515-11e4-b510-962fcfabc310_story.html?tid=a_inl (“The Justice
Department and FBI have formally acknowledged that nearly every
examiner in an elite FBI forensic unit gave flawed testimony in almost all
trials in which they offered evidence [about hair matches] against criminal
defendants over more than a two-decade period.”); Adam Liptak, You
Think DNA Evidence is Foolproof? Try Again, New York Times (Mar. 16,
2003), http://www.nytimes.com/2003/03/16/weekinreview/the-nation-you-
think-dna-evidence-is-foolproof-try-again.html.
                     GIMENEZ V. OCHOA                         17

petitioner’s one-year deadline to file a habeas petition under
AEDPA.

     The Third Circuit permits petitioners to seek relief from
convictions based on flawed forensic evidence. In Albrecht
v. Horn, the court suggested that a petitioner may claim that
scientific evidence introduced at trial violated his due process
rights if he could show that the evidence “infect[ed] his entire
trial with error of constitutional dimensions.” 485 F.3d 103,
124 n.7 (3d Cir. 2007) (quoting Murray v. Carrier, 477 U.S.
478, 494 (1986)). Such a petition for relief is not a “free-
standing innocence claim,” but a due process claim. Lee v.
Houtzdale SCI, 798 F.3d 159, 162 (3d Cir. 2015) (interpreting
Lee v. Glunt, 667 F.3d 397, 403 n.5 (3d Cir. 2012)). Relying
on this rule, the Lee court granted habeas relief to a petitioner
whose conviction rested on flawed arson forensics, which the
government conceded had been rendered invalid by
subsequent scientific developments. Id. at 167. The
remaining evidence at his trial wasn’t sufficient to show that
the petitioner was guilty beyond a reasonable doubt. Id. at
169.

    We join the Third Circuit in recognizing that habeas
petitioners can allege a constitutional violation from the
introduction of flawed expert testimony at trial if they show
that the introduction of this evidence “undermined the
fundamental fairness of the entire trial.” Id. at 162. Yet
Gimenez isn’t entitled to relief. He failed to show that
permitting the prosecution’s experts to testify based on a
triad-only theory of SBS was “so extremely unfair that it[] . . .
violate[d] fundamental conceptions of justice.” Dowling,
493 U.S. at 352 (internal quotation marks omitted). Gimenez
presented literature revealing not so much a repudiation of
triad-only SBS, but a vigorous debate about its validity within
18                   GIMENEZ V. OCHOA

the scientific community.          In 2006, one textbook
acknowledged that “there is a dispute of whether inflicted
subdural hematomas can occur from shaking alone.” In 2011,
the triad theory of SBS was characterized merely as being
under challenge. See Cavazos v. Smith, 132 S. Ct. 2, 10
(2011) (Ginsburg, J., dissenting) (commenting on the shift in
scientific opinions about SBS). The debate continues to the
present day. See Debbie Cenziper et al., Shaken Science:
Prosecutors Build Murder Cases on Disputed Shaken Baby
Syndrome Diagnosis, Wash. Post (Mar. 20, 2015),
https://www.washingtonpost.com/graphics/investigations/s
haken-baby-syndrome/.

     In any case, Gimenez can’t prove by “clear and
convincing evidence” that “no reasonable factfinder” would
have found him guilty but for the introduction of purportedly
flawed SBS testimony. 28 U.S.C. § 2244(b)(2)(B)(ii); see
Gage v. Chappell, 793 F.3d 1159, 1168 (9th Cir. 2015). That
inquiry requires courts to examine the alleged constitutional
violation “in light of the evidence as a whole” at a petitioner’s
trial. 28 U.S.C. § 2244(b)(2)(B)(ii); Jones v. Ryan, 733 F.3d
825, 845 (9th Cir. 2013). A juror could still have concluded
that Priscilla was shaken to death based on her numerous
suspicious injuries, Gimenez’s inconsistent statements about
Priscilla’s torn frenulum and his admitted violent behavior.
Even assuming the prosecution’s experts couldn’t testify that
the triad alone establishes SBS, the evidence Gimenez
presents isn’t enough to show by clear and convincing
evidence that “no reasonable factfinder” would have found
him guilty. Jones, 733 F.3d at 845; Gage, 793 F.3d at 1168.
                    GIMENEZ V. OCHOA                       19

        2. Freestanding Actual-Innocence Claim

    Nor could Gimenez obtain relief if we were to decouple
his claim of actual innocence from any due process violation
and repackage it as a freestanding “actual innocence” claim.
See Herrera, 506 U.S. at 417. For one, we have only
assumed, but have not held, that petitioners may bring such
a freestanding innocence claim. Jones v. Taylor, 763 F.3d
1242, 1246 (9th Cir. 2014). And our cases suggest that relief
would be available, if at all, only in very narrow
circumstances. Gimenez must “go beyond demonstrating
doubt about his guilt, and must affirmatively prove that he is
probably innocent.” Carriger v. Stewart, 132 F.3d 463, 476
(9th Cir. 1997) (en banc).

    Gimenez’s “new” evidence doesn’t undermine the
prosecution’s case so much as beef up the theory that the jury
already rejected: Priscilla suffered from health problems at
birth that caused her subdural hematoma, brain swelling,
retinal hemorrhage and eventually her death. Introducing a
superior version of the same evidence supporting the theory
doesn’t “affirmatively prove that [Gimenez] is probably
innocent.” Id. The evidence falls far short of a persuasive
alibi, exculpatory physical evidence or a credible confession
from another suspect—all of which are types of new evidence
that we have suggested could meet this demanding standard.
Id. at 477.

                         *    *   *

    We acknowledge that AEDPA’s requirements make it
extremely difficult to reexamine convictions based on
scientific theories that are presently in flux. But challenges
to flawed expert testimony are cognizable in successive
20                  GIMENEZ V. OCHOA

habeas petitions. While Gimenez may not meet the exacting
prerequisites for obtaining relief from his conviction, he and
others may be able to do so in the future as forensic science
continues to evolve.

     AFFIRMED.
