                      FOR PUBLICATION

    UNITED STATES COURT OF APPEALS
         FOR THE NINTH CIRCUIT


 UNITED STATES OF AMERICA,                    No. 16-10261
           Plaintiff-Appellee,
                                               D.C. No.
                 v.                       4:14-cr-01750-RCC-
                                                 DTF-1
 LASHAY MARIE LOPEZ,
        Defendant-Appellant.                     OPINION


        Appeal from the United States District Court
                 for the District of Arizona
         Raner C. Collins, Chief Judge, Presiding

         Argued and Submitted November 17, 2017
                 San Francisco, California

                      Filed January 10, 2019

 Before: Johnnie B. Rawlinson and Jay S. Bybee, Circuit
     Judges, and Paul L. Friedman,* District Judge.

                   Opinion by Judge Bybee;
                  Dissent by Judge Rawlinson




    *
      The Honorable Paul L. Friedman, United States District Judge for
the District of Columbia, sitting by designation.
2                    UNITED STATES V. LOPEZ

                            SUMMARY**


                            Criminal Law

    The panel vacated a conviction for false statement during
the purchase of a firearm, aggravated identity theft, and felon
in possession of a firearm, in a case in which the only issue
before the jury was the affirmative defense of duress.

    The panel held that expert testimony on Battered Woman
Syndrome may be used by a defendant to support her duress
defense and rehabilitate her credibility, that the district court
therefore erred in precluding the defendant’s expert witness
from testifying, and that this decision was prejudicial to her
defense.

    The panel held that the district court did not abuse its
discretion by excluding a video of the defendant’s entire
interview in jail with ATF agents, where the evidence would
have consisted nearly exclusively of hearsay statements,
including those made by the defendant.

    Dissenting, Judge Rawlinson could not say that the
district judge abused his discretion in determining that the
expert testimony on Battered Woman Syndrome was not
admissible in the context of establishing a duress defense, as
opposed to the usual context of its admission—to establish
self-defense.

    The panel remanded for a new trial.

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

                        COUNSEL

Michael L. Burke (argued), Assistant Federal Public
Defender; Jon M. Sands, Federal Public Defender; Office of
the Federal Public Defender, Phoenix, Arizona; for
Defendant-Appellant.

Erica Anderson McCallum (argued), Assistant United States
Attorney; Robert L. Miskell, Appellate Chief; Elizabeth A.
Strange, Acting United States Attorney; United States
Attorney’s Office, Tucson, Arizona; for Plaintiff-Appellee.


                         OPINION

BYBEE, Circuit Judge:

    Defendant-Appellant Lashay Marie Lopez was convicted
on three federal charges stemming from her purchase of a
firearm through the use of false identification (ID). Because
Lopez admitted to the offense conduct, the only issue before
the jury was the affirmative defense of duress. Lopez claims
that she purchased a handgun for Hector Karaca using her
identical twin sister’s ID in violation of her probation and
federal law because Karaca threatened to harm Lopez and her
family if she failed to acquire a gun for him.

    In support of her duress defense, Lopez asked the district
court to allow her to introduce expert testimony on Battered
Woman Syndrome (BWS) and the effects of past abuse.
Lopez, who had been physically and sexually abused by her
stepfather, contended that this evidence would “help provide
context” to the jury regarding her fear of Karaca and why she
did not seek help from the police. Lopez similarly asserted
4                   UNITED STATES V. LOPEZ

that the expert’s description of the “characteristics of [a]
domestic violence victim” would help explain her
“counterintuitive” behavior regarding Karaca. The court,
however, excluded this evidence in a series of oral rulings,
concluding that BWS evidence is incompatible with the
duress defense’s use of an objective reasonable-person
standard.

    We join the weight of authority in holding that such
expert testimony may be used by a defendant to support her
duress defense and rehabilitate her credibility. We therefore
find that the district court committed legal error in precluding
Lopez’s expert witness from testifying and conclude that this
decision was prejudicial to her defense. Accordingly, we
vacate her conviction and remand this case to the district
court for a new trial.

               I. FACTS AND PROCEEDINGS

                                 A

    Lopez, who was twenty-seven years old at the time of the
crimes at issue, dated Karaca when the two were teenagers.
The relationship ended when Karaca was sentenced to eight-
years imprisonment in 2006 for a convenience-store
shooting.1 Karaca was released from prison during the Fall of
2013, but mere weeks later, police were searching for him in
connection with a double homicide in Phoenix, Arizona.

   In November 2013, Karaca arrived at Lopez’s home in
Tucson, where she lived with her mother, her identical twin

    1
        It was, however, disputed at trial whether the two remained in
contact while he was in prison.
                  UNITED STATES V. LOPEZ                      5

sister, her sister’s two young children, and a teenage sibling.
Karaca and Lopez spoke for several hours and drank together.
Karaca eventually admitted to Lopez that night that he was
“on the run” from the police due to a shooting and asked her
if she knew where he could get a gun. She told him she did
not, and Karaca accepted her answer. He later began making
sexual advances towards Lopez, suggesting that they restart
their relationship. Lopez initially rejected these overtures,
telling Karaca that she was currently involved with someone
else. Lopez “push[ed] him away” and “told him no . . . but he
didn’t stop” and “so [Lopez] just gave in.” Karaca eventually
left without further incident.

    Two days later, however, Karaca returned to Lopez’s
home and again asked her about acquiring a gun. She
explained to him at this point that she could not purchase a
gun or “be around” one because she was on probation on a
felony drug conviction. Karaca responded by grabbing Lopez
by the arm and threatening that, if she failed to get him a gun,
“he[] [would] come back and shoot up [her] house and he
[would] hurt [her] family.” Several days later, Karaca
returned to Lopez’s home and was limping. He told her that
he was in a “shootout” in the desert during a drug deal and
was shot in the leg. Lopez later testified at her trial that
Karaca’s reference to a “shootout” made her believe that he
already had a gun, which increased her fear that he would
harm her family.

    Four days later, Karaca returned and demanded that
Lopez purchase a gun for him that day from a nearby
pawnshop. She again responded that she was on probation.
Karaca then insisted that Lopez pose as her identical twin
sister during the purchase, demanding that they go to Lopez’s
home and retrieve her sister’s ID. After Lopez made various
6                 UNITED STATES V. LOPEZ

excuses as to why she could not obtain the ID that day,
Karaca grabbed her again and threatened: “I already told you
what I was going to do if you don’t get this gun for me. I
know you don’t want anything happening to your mom or
your sisters.” The two retrieved the ID and went to the
pawnshop that same day, where Lopez purchased a Ruger
pistol using the ID and her sister’s identifying information.
Shortly after she left the store, Karaca grabbed her purse,
removed the gun, and walked away.

    Two days later, Lopez saw Karaca one last time before
her arrest. The two went together to a family barbeque hosted
by her twin sister’s ex-husband, who was also Karaca’s
friend. The three left the party at one point to go to the store,
where Karaca accused Lopez of flirting with her sister’s ex-
husband and slapped her in the face. Karaca initially left but
eventually returned to the party. Later that evening, Karaca
grabbed Lopez’s arm and told her he would “f--- [her] up, and
no one will do anything about it.”

    Twelve days after purchasing the gun for Karaca, Lopez
met with her probation officer and a U.S. Marshal, who was
searching for Karaca. Lopez initially denied knowing
Karaca, but after the probation officer found the pawnshop
receipt in Lopez’s purse, she admitted that she had purchased
a gun for Karaca. Lopez also stated she was seeing Karaca
romantically, referring to him at one point as “my man.”
Lopez did not explain to the officers at this juncture why she
had bought the gun for Karaca and did not claim that Karaca
had threatened her. After refusing to provide them with any
specifics on Karaca’s location, Lopez was sent to jail. She
later explained at trial that she was afraid that Karaca would
harm her if he discovered she had spoken to the authorities.
                  UNITED STATES V. LOPEZ                     7

    The following day, two agents with the Bureau of
Alcohol, Tobacco, Firearms, and Explosives (ATF)
interviewed Lopez in a private room in the jail. For the first
time, Lopez claimed that she had purchased the gun for
Karaca because he had threatened her and her family. She
also informed the agents that Karaca had told her he had
another gun. At trial, Lopez claimed that she only told the
ATF agents these details—as opposed to her probation officer
the previous day—because she felt “safer in the jail”:
“[Karaca] can’t get me when I’m . . . in jail. There is no way
of him getting ahold of me and finding out what I’m saying”
to the agents. Shortly thereafter, the police located Karaca in
Tucson. He stole a vehicle using the gun purchased by Lopez
and led the police on a lengthy car chase, which ended with
Karaca taking his own life.

                              B

    In late 2014, Lopez was indicted on three federal charges:
(1) false statement during the purchase of a firearm under
18 U.S.C. §§ 922(a)(6), 924(a)(2); (2) aggravated identity
theft under 18 U.S.C. §§ 1028A(a)(1), (c)(3); and (3) felon in
possession of a firearm under 18 U.S.C. §§ 922(g)(1),
924(a)(2). The case proceeded to a jury trial. Lopez
stipulated to many of the elements of these offenses and
conceded that she purchased the firearm using the false ID.
Her trial strategy thus consisted entirely of proving that she
acted under duress as a result of Karaca’s threats against her
and her family.

    “Duress is not a statutory defense, but a common-law
defense that allows a jury to find that the defendant’s conduct
is excused, even though the government has carried its burden
of proof.” United States v. Kuok, 671 F.3d 931, 947 (9th Cir.
8                 UNITED STATES V. LOPEZ

2012). In order to establish the defense, a defendant bears the
burden of proving three elements by a preponderance of the
evidence: “(1) [s]he was under an immediate threat of death
or serious bodily injury, (2) [s]he had a well grounded fear
that the threat would be carried out, and (3) [s]he had no
reasonable opportunity to escape.” Id.; see also United States
v. Navarro, 608 F.3d 529, 532 (9th Cir. 2010); United States
v. Johnson, 956 F.2d 894, 897 (9th Cir. 1992), superseded by
regulation on other grounds; United States v.
Contento-Pachon, 723 F.2d 691, 693 (9th Cir. 1984)). If
successful, a defendant is “legally excuse[d]” of the crime
committed and must be found not guilty. Navarro, 608 F.3d
at 532–33.

    Prior to trial, Lopez advised the district court of her intent
to introduce testimony from Dr. Cheryl Karp, an expert “on
issues of trauma, domestic violence, and victim behaviors.”
Lopez asserted that Dr. Karp’s testimony would assist the
jury “in understanding the evidence because . . . the trial
[would] involve evidence as to coercion and threats of
violence leading up to the day Karaca took her from her home
and forced her to purchase a firearm for him.” Lopez further
contended that Dr. Karp’s testimony regarding “behaviors of
victims of domestic violence” would “help provide context”
to her duress defense, including whether her fear of Karaca
was “well-grounded” and whether she had a “reasonable
opportunity” to escape from him. Finally, Lopez asserted that
Dr. Karp’s testimony would “liken to that of standard
government expert testimony in a domestic violence case
where there is the counter-argument that the victim’s
behavior was not consistent or credible victim behavior.”

    The government moved in limine to exclude this
testimony, primarily arguing that the testimony would be
                  UNITED STATES V. LOPEZ                      9

irrelevant because the duress defense applies an objective
standard. In an oral ruling, the district court described the
issue as “pretty close” but ultimately granted the
government’s motion: “I don’t see how [Dr. Karp] can do
anything to tell this jury how a reasonable person would have
acted under the circumstances, so I’m not letting her in for
that purpose.” Lopez moved for reconsideration at several
points during trial, which the court orally denied each time.
The district court did, however, instruct the jury on the duress
defense and permitted Lopez herself to testify about how her
experience as an abuse victim influenced her interactions with
Karaca.

    After the jury rendered a guilty verdict on all counts,
Lopez moved for a new trial, arguing in part that the
preclusion of Dr. Karp’s testimony prejudiced her defense.
Included with the motion was Dr. Karp’s affidavit, in which
she provided more detail as to her intended testimony.
Specifically, Dr. Karp asserted that “[t]he jury [did] not have
the proper knowledge base to understand some of the
psychological explanations as to the dynamics involved in
Battered Woman Syndrome and why Battered Women
remain with abusive men, including the theory of Learned
Helplessness.” She further attested that her “testimony would
also have given the jury an opportunity to hear from an expert
on Trauma and how that may have influenced [Lopez’s]
feelings when she did not seek the help of the police, given
her own trauma history of being sexually abused by her step-
father and the police never protecting her.” The court denied
the motion in an oral ruling.

   The court eventually sentenced Lopez to a combined 30-
months imprisonment. Lopez filed a timely appeal, and we
have jurisdiction under 28 U.S.C. § 1291.
10                    UNITED STATES V. LOPEZ

                            II. ANALYSIS

    Lopez claims that two erroneous evidentiary rulings
prejudiced her duress defense. First, she argues that the
district court erroneously excluded Dr. Karp’s testimony
regarding BWS. Because we hold that the district court
committed reversible error by barring this expert testimony,
we devote the bulk of our discussion below to addressing why
such evidence is generally admissible. We then conclude by
briefly addressing (and ultimately rejecting) Lopez’s separate
argument that the district court erred by excluding a video of
her entire interview in jail with the ATF agents.2

                                     A

    Lopez argues that Dr. Karp’s testimony supports two
elements of the duress defense: (1) whether Lopez had a
well-grounded fear that Karaca would harm her and her
family if she refused to purchase a gun for him and (2)
whether she had a reasonable opportunity to escape from him
by calling the police. The government continues to counter
that BWS evidence is incompatible with a duress defense

     2
        Lopez also claims that the government engaged in prosecutorial
misconduct during its cross examination of her by stating, in response to
one of her answers, “Well, that’s just a lie right now” and, at several other
points, “Does that make sense?” Although the district court gave the jury
a curative instruction—“that what the lawyers said in their questioning and
cross-examination is not evidence”—Lopez contends that the court should
have cited the prosecutor’s specific comments. On appeal, the
government concedes that the “that’s just a lie” comment was improper
but contends that the curative instruction was sufficient and that any
potential error was harmless. Given the government’s concession and the
fact that we are remanding for a new trial, we need not address this claim.
Similarly, we also decline to address Lopez’s claim of cumulative error.
                     UNITED STATES V. LOPEZ                           11

because both aforementioned elements assess objective
reasonableness. See United States v. Willis, 38 F.3d 170, 176
(5th Cir. 1994); Johnson, 956 F.2d at 898. BWS, the
government argues, reflects only a defendant’s “subjective
vulnerability.”

   Like the majority of courts that have addressed this
question, we are unpersuaded by this proposed distinction.
Before turning to these authorities, however, we must first
address our decision in Johnson, which the government
argued before the district court controls this question.3

                                    1

    Johnson involved several female defendants who were
convicted for their nominal participation in a violent drug
organization. 956 F.2d at 897. Three of the defendants—
Wood, Johnson, and Breck—had claimed that they acted
under duress from the organization’s “kingpin,” who
threatened and assaulted two of the defendants and their
immediate family members. Id. at 897–99, 901–02. The
district court permitted testimony on BWS from an expert on
behalf of Wood, but denied Johnson and Beck the opportunity
to call an expert or cross-examine Wood’s expert. Id.
Because the jury nonetheless found all three defendants
guilty, “[t]he dominant issue on the appeals of” these

    3
        The government sparingly cites Johnson on appeal, and it no
longer appears to assert that we decided in Johnson that BWS supports
evidence only of subjective reasonableness. But because at least one other
court has interpreted Johnson in this manner, we must ensure that we are
not bound by our prior decision. See Willis, 38 F.3d at 175 (“[T]he
Johnson court found that subjective evidence of the battered woman’s
syndrome could not be taken into account in determining criminal liability
and thus could not upset the convictions.”).
12                UNITED STATES V. LOPEZ

defendants was “the duress defense as it interacts with
sentencing.” Id. at 897. Indeed, we remanded these
defendants’ cases for resentencing, in part, because the
district court erroneously believed that it lacked the authority
under the sentencing guidelines to depart downward based on
duress if a defendant failed to prove the affirmative defense
at trial. Id. at 900–03.

    Before addressing each defendant’s claims, we discussed
the principles underlying duress generally. We specified that
the defense applies an objective, reasonable-person standard:

           The formula is addressed to the impact of
       a threat of force upon a reasonable person:
       The fear must be “well-grounded.” There
       must be no “reasonable” opportunity to
       escape. The formula is in harmony with the
       analysis of duress in the Model Penal Code
       which recognizes duress in the use of
       unlawful force “that a person of reasonable
       firmness in his [or her] situation would have
       been unable to resist.” American Law
       Institute, Model Penal Code § 2.09(i) (1985).

Id. at 898. In determining whether a fear is well-grounded,
the jury may “take into account the objective situation in
which the defendant was allegedly subjected to duress. Fear
which would be irrational in one set of circumstances may be
well-grounded if the experience of the defendant with those
applying the threat is such that the defendant can reasonably
anticipate being harmed on failure to comply.” Id. (emphasis
added). In Johnson, for instance, there was little doubt that
the jury, in assessing the reasonableness of the defendants’
fear, could properly consider the fact that the defendants had
                  UNITED STATES V. LOPEZ                       13

witnessed the kingpin commit brutal acts against others. See,
e.g., id. at 898 (“Given the violence that [one defendant] had
already observed on the part of [the kingpin], including his
putting of dynamite in her housemate[’s] . . . mouth, she was
under threat of immediate severe physical harm.”).

    The more difficult question was “whether a special
vulnerability to fear—a vulnerability not produced by those
persons causing the defendant’s criminal action—may be
taken into account.” Id. at 898 (emphasis added). We noted
that, “[a]s a defense to a charge of criminal conduct, such
subjective vulnerability has not been admitted.” Id. Our
analysis at this juncture was brief and opaque, however, as we
provided no elaboration on what constitutes a special,
subjective vulnerability to fear.

    Instead, we reasoned that there are factors related solely
to the defendant—rather than to the coercing, threatening
party—that may be considered in the reasonableness inquiry.
Relying on the Model Penal Code (MPC), we highlighted
“[s]tark, tangible factors,” such as a person’s “size, strength,
age, or health.” Id. (quoting MODEL PENAL CODE § 2.09 cmt.
3 (AM. LAW INST. 1985)); see also MODEL PENAL CODE
§ 2.09 cmt. 3 (“The [‘person of reasonable firmness’]
standard is not, however, wholly external in its reference;
account is taken of the actor’s ‘situation,’ a term that should
here be given the same scope it is accorded in appraising
recklessness and negligence.”). Indeed, a 5’ 3”, 100 lbs., 80-
year old individual will, all else equal, likely perceive a threat
of physical violence differently than a 6’ 4”, 200 lbs., 25-year
old. While we then acknowledged that the MPC did not list
“gender as one of the ‘stark, tangible factors,’” we assured
that our analysis would demonstrate that “there are sets of
14               UNITED STATES V. LOPEZ

circumstances in which gender is also a factor to be
considered.” Johnson, 956 F.2d at 898.

    Once we turned to the claims raised by three of the female
defendants, it became evident that our mention of “gender”
referred to BWS evidence. At trial, one of the defendants,
Wood, “buttressed her contention of duress with the” expert
testimony of a psychologist who “had substantial experience
in dealing with battered women.” Id. at 899. Summarizing
this testimony and the texts the psychologist cited, we
explained that BWS

       is a set of psychological and behavioral
       reactions exhibited by victims of severe,
       long-term, domestic physical and emotional
       abuse. L. Walker, The Battered Woman
       Syndrome (1984). Battered woman syndrome
       is not a mental disease or defect; rather,
       battered woman syndrome is a post-traumatic
       stress disorder. Its psychological effects are
       often similar to the effects of imprisonment on
       kidnap victims and prisoners of war. Once
       battered women believe themselves to be
       helpless victims of abusive men, they behave
       like hostages and link themselves to their
       captors out of fear that it is the only way to
       survive. Battered women are unable to
       respond effectively to violence because they
       are psychologically trapped in the violent
       relationship.

           Repeated beatings diminish the battered
       woman’s motivation to respond and instill in
       her a negative belief about the effectiveness of
                 UNITED STATES V. LOPEZ                    15

       her actions. This “learned helplessness”
       keeps the battered woman from leaving her
       batterer. One of the primary survival skills of
       battered women is hyperalertness. The
       battered woman learns to be sensitive to her
       environment to prevent further violence to
       herself. The development of survival skills,
       however, comes “at the expense of escape
       skills.” L. Walker at 33 & 87-89. Society
       often misinterprets the survival skills of
       battered women as signs of passivity and
       weakness coupled with an unwillingness to
       leave the violent relationship. Id. at 33. A
       common misunderstanding is that the battered
       woman’s responses are indicative of weak
       character. Rather, these responses must be
       seen as attempts to cope with the abusive and
       controlling environment in which she lives
       and from which she is helpless to escape.

Id.

    Although the duress defense did not sway the jury, we
held that the district court “should properly consider the
individual before the court and her particular vulnerability”
in sentencing. Id. BWS evidence, we concluded, “has a
particular relation to the defense of duress as it has been
expanded by the commentary to the Model Penal Code.” Id.
at 900. We highlighted the MPC’s citation to “[a] leading
authority on the common law [who] added that the defense
applies when the defendant is so far ‘in thrall to some power’
that a legal sanction would be ineffective in controlling any
choice that may be made.” Id. (quoting GLANVILLE
WILLIAMS, CRIMINAL LAW: THE GENERAL PART 755–62 (2nd
16                UNITED STATES V. LOPEZ

ed. 1961)); see also MODEL PENAL CODE § 2.09 cmt. 2. We
described this model of duress as a “substantial expansion of
the defense,” which we cautioned “may go too far if not
linked to gross and identifiable classes of circumstances.” Id.
But we concluded that “[b]attered women are in
circumstances forming such a class.” Id.

    Regrettably, our discussion in Johnson of BWS provides
no guidance on the appropriate role of such evidence in
supporting the affirmative defense of duress at trial. We
noted, without approval or disapproval, that Wood was
permitted to call an expert on BWS, who testified not only on
BWS generally, but opined that Wood “fitted the profile of a
battered woman.” Id. at 899.

    Nor did we add clarity in addressing the claims raised by
the other defendants. Johnson claimed that she should have
been permitted either to call the same expert as Wood or
cross-examine her. Id. at 901. We found no abuse of
discretion in the exclusion of such evidence because the
expert had never examined Johnson and could only have
testified as to “a stereotype applied to a case she knew only
in the most external way.” Id.

    The third defendant, Breck, also contended that the
district court erred in denying her a jury instruction on duress
and by precluding her from calling the BWS expert on her
own behalf. Id. at 902. Unlike the other two defendants who
had claimed duress, “Breck began to work for [the kingpin]
without any overt threat on his part, and she continued to
work for him without such threats being made directly.” Id.
Rather, Breck’s defense relied solely on her testimony that
she had once seen his bodyguards strike a woman and had
“herself heard on numerous occasions from [the kingpin] of
                  UNITED STATES V. LOPEZ                    17

his violent treatment of persons who crossed him.” Id. We
upheld her conviction. Breck, we reasoned, “had not made
out a prima facie case of duress because she had made no
showing that she could not far earlier have escaped [the
kingpin], as she in fact finally did.” Id. Moreover, the expert
witness’ “testimony, going to [Breck’s] special subjective
vulnerability, would not have established the lack of
opportunity to escape that the defense of duress requires.” Id.

    Ultimately, we remanded all three defendants to the
district court for resentencing. Even though the defendants
had not proven their defense of duress at trial, the district
court could take into account at sentencing their “subjective
vulnerability” and, as appropriate, “depart downwards on the
grounds of incomplete duress.” Id. at 903.

    There is language in Johnson that lends support to the
government’s argument here that BWS evidence is
incompatible with the duress defense’s objective
reasonableness standard. See id. at 898. But we decline to
apply such a broad reading to our brief discussion of the three
defendants’ evidentiary challenges. Wood was permitted the
use of an expert to testify at trial as to BWS generally and as
to Wood’s own profile. Id. at 899. Johnson was denied the
use of the same expert, in part because she wanted the expert
to testify as to her motivation, and the expert had never
examined Johnson. Id. at 901. As to the third defendant,
Breck, we held only that she lacked the elements of a prima
facie duress defense because she was not actually threatened
directly by the drug kingpin and ultimately escaped. Id. at
902.

   Unfortunately, our Johnson decision never elaborated on
what it meant for Breck to have had a reasonable opportunity
18                   UNITED STATES V. LOPEZ

to escape from the kingpin. We thus have no means of
discerning what factors led us to conclude that Breck’s duress
defense was so lacking in evidentiary support that she failed
to make out a prima facie case, nor can we discern how BWS
evidence might have influenced those factors. If, for
instance, Breck had decided not to call the police at the first
opportunity, then a decision holding that BWS evidence was
inadmissable in assessing the reasonableness of her decision
would certainly be relevant to the case before us.
Unfortunately, Johnson does not supply these answers. We
must, therefore, conclude that our holding was limited to the
dearth of duress evidence in Breck’s case. We are unwilling
to read Johnson as establishing a categorical bar on BWS
evidence in support of a duress defense at trial; we think that
reads too much into Johnson. See United States v. Marenghi,
893 F. Supp. 85, 93 (D. Me. 1995) (“[T]he admissibility of
expert testimony during trial in a duress defense was not
squarely before the appellate court in Johnson”).

    Our conclusion is bolstered by United States v. Homick,
964 F.2d 899 (9th Cir. 1992), which we decided mere months
after Johnson.4 There, a woman and her ex-husband were
tried for wire fraud stemming from her falsified affidavit
regarding stolen jewelry. 964 F.2d at 901–02. The female
defendant claimed that she acted under duress from her ex-
husband, and on appeal, contended “that the district court

     4
       Our conclusion is also consistent with our non-BWS precedent,
which has allowed consideration of factors unique to the defendant, rather
than the threatening party, in assessing whether the defendant had a
reasonable opportunity to escape. See, e.g., Contento-Pachon, 723 F.2d
at 694 (holding that it is the jury’s role to “decide whether one in [the
defendant’s] position might believe that some of the Bogota police were
paid informants for drug traffickers and that reporting the matter to the
police did not represent a reasonable opportunity of escape”).
                  UNITED STATES V. LOPEZ                    19

improperly excluded expert testimony regarding battered
woman syndrome and thereby deprived her of her theory of
defense.” Id. at 905. We found no error in this exclusion, as
the wiretapped phone calls between her and her ex-husband
revealed “[t]here was nothing implicitly or explicitly
threatening about [their] conversation[s]” and she “readily
agreed” to write the fraudulent affidavit. Id. at 906. In
reaching this conclusion, we stated that “[t]he battered
woman defense is a species of the defense of duress.” Id. at
905. And, citing to Johnson, “[w]e recognize[d] that the
unique nature of battered woman syndrome justifies a
somewhat different approach to the way we have historically
applied” the duress defense. Id. Homick thus adds little
clarity to the proper role of BWS evidence at trial except for
this: It demonstrates that we have not viewed evidence of
BWS as categorically incompatible with duress. Rather, as
in Johnson, we rejected the defendant’s claim of duress based
on the lack of evidence supporting the affirmative defense.


    Here, Lopez testified that Karaca—a convicted felon
fleeing from the police—threatened to harm her and her
family if she failed to comply with his demands and that she
feared that he would carry out these threats if she went to the
police. Such evidence was more than sufficient to warrant a
duress instruction, which Lopez received. We must therefore
address the question left unanswered in our prior decisions:
what role BWS evidence may play in supporting the
affirmative defense of duress.

                              2

   We do not begin from a blank slate. Because duress is a
common-law defense, state and federal courts have long
20                   UNITED STATES V. LOPEZ

opined on its application and parameters. See Johnson, 956
F.2d at 897 (“The defense of duress is a common law concept
that federal criminal law has incorporated.”). Tellingly, the
government has cited to only one jurisdiction that
categorically bars BWS evidence in the duress context.5 In
Willis, the Fifth Circuit held that BWS evidence is
“inherently subjective” and thus incompatible with the duress
defense’s objective, reasonable-person standard. 38 F.3d at
175. The court reasoned that

         [s]uch evidence is not addressed to whether a
         person of reasonable firmness would have
         succumbed to the level of coercion present in
         a given set of circumstances. Quite the
         contrary, such evidence is usually consulted to
         explain why this particular defendant
         succumbed when a reasonable person without
         a background of being battered might not
         have.      Specifically, battered woman’s
         syndrome evidence seeks to establish that,
         because of her psychological condition, the
         defendant is unusually susceptible to the
         coercion.



     5
        Curiously, the government also cites United States v. Smith, 987
F.2d 888 (2d Cir. 1993). In that case the district court declined to appoint
the defendant a psychiatrist “on the ground that testimony as to [the
defendant’s] unusual susceptibility to coercion was irrelevant and
inadmissible.” Smith, 987 F.2d at 891. The Second Circuit held this was
error: “A psychiatrist might have testified to other issues at trial and
sentencing, including that [the defendant’s] behavior was not inconsistent
with his being under duress. . . . Explaining this behavior might have
bolstered the credibility of his duress claim, which was relevant to the
jury’s determination.” Id.
                     UNITED STATES V. LOPEZ                           21

Id. (emphasis added); see also United States v. Dixon, 413
F.3d 520, 523–24 (5th Cir. 2005) (applying Willis in a case
involving facts similar to the instant case), aff’d on other
grounds, 548 U.S. 1 (2006).

    In contrast, in a recent case the D.C. Circuit observed that
“[m]ost courts that have considered th[is] question—
especially in recent years—have recognized that expert
testimony on battered woman syndrome can be relevant to
prove duress.” United States v. Nwoye, 824 F.3d 1129, 1136
(D.C. Cir. 2016) (Kavanaugh, J.). In Nwoye, the D.C. Circuit
concluded that “expert [BWS] testimony can help a jury
assess whether a battered woman’s actions were reasonable.”
Id. Reasonableness, the court explained, “is not assessed in
the abstract. Rather, any assessment of the reasonableness of
a defendant’s actions must take into account the defendant’s
‘particular circumstances,’ at least to a certain extent.” Id. at
1137 (emphasis added).

    Turning first to whether a defendant who suffers from
BWS can have a well-grounded fear that the threat will be
carried out against her,6 the court explained that “women in

    6
        The D.C. Circuit describes the duress defense as a two-element
test: (1) whether the defendant “acted under an unlawful threat of
imminent death or serious bodily injury” and (2) whether “there was no
‘reasonable, legal alternative to committing the crime.’” Nwoye, 824 F.3d
at 1135 (quoting United States v. Nwoye, 663 F.3d 460, 462 (D.C. Cir.
2011)). Because the D.C. Circuit has stated that reasonableness is a
component of both elements, id. at 1137, we interpret this test as the
functional equivalent of our own three-part test. Its first element merely
combines the question of whether the defendant suffered “an immediate
threat of death or serious bodily injury” and whether she had “a
well-grounded fear that the threat will be carried out.” Johnson, 956 F.2d
at 897. Moreover, we see no meaningful distinction between whether the
defendant had a “reasonable opportunity to escape the threatened harm,”
22                   UNITED STATES V. LOPEZ

battering relationships are often ‘hypervigilant to cues of
impending danger and accurately perceive the seriousness of
the situation before another person who had not been
repeatedly abused might recognize the danger.’” Id.
(emphasis added) (quoting Lenore E.A. Walker, Battered
Women Syndrome and Self-Defense, 6 NOTRE DAME J.L.
ETHICS & PUB. POL’Y 321, 324 (1992)). Thus, “[r]emarks or
gestures that may seem harmless to the average observer
might be reasonably understood to presage imminent and
severe violence when viewed against the backdrop of the
batterer’s particular pattern of violence.” Id.; see also
Marenghi, 893 F. Supp. at 95 (“Providing the jury with
information of specific incidents of abuse while providing no
information about how such treatment can, over time,
establish a dynamic where the threat of abuse hovers over
every interaction between the individuals, even if such threat
is not always articulated, would give the jury only half of the
story.    In effect, [BWS] expert testimony may be
characterized as explaining how a reasonable person can
nonetheless be trapped and controlled by another at all times
even if there is no overt threat of violence at any given
moment.”).

    As to the separate inquiry of whether a defendant has a
reasonable opportunity to escape the threatened harm, the
D.C. Circuit concluded that “battered women face significant
impediments to leaving abusive relationships.            Most
importantly, battered women who leave their abusers risk a
retaliatory escalation in violence against themselves or those
close to them—sometimes termed ‘separation abuse.’”
Nwoye, 824 F.3d at 1137–38 (quoting Mary Ann Dutton,


id., and whether she had a “reasonable, legal alternative to committing the
crime,” Nwoye, 824 F.3d at 1135.
                  UNITED STATES V. LOPEZ                     23

Validity of “Battered Woman Syndrome” in Criminal Cases
Involving Battered Women, in DEPARTMENT OF JUSTICE, ET
AL., THE VALIDITY AND USE OF EVIDENCE CONCERNING
BATTERING AND ITS EFFECTS IN CRIMINAL TRIALS pt. I, at
14–15 (1996)). “Expert testimony on those impediments to
separation can help explain why a battered woman did not
take advantage of an otherwise reasonable-sounding
opportunity to avoid committing the alleged crime.” Id. at
1138 (emphasis added). Indeed, a defendant’s experiences
may lead her to “reasonably believe[] that reporting [the
threatening party] to the police (or others) would have been
unlikely to result in his immediate arrest and would . . .
therefore place[] her at greater risk in the interim.” Id.
at 1139.

    As the court in Nwoye observed, the majority of
courts—federal and state—that have addressed BWS in the
context of a duress defense have concluded that such
evidence is relevant and may be admitted. See, e.g., Dando
v. Yukins, 461 F.3d 791, 801 (6th Cir. 2006); United States v.
Ramirez, 87 Fed. R. Evid. Serv. 1154 (D.P.R. 2012); United
States v. Ceballos, 593 F. Supp. 2d 1054, 1060–63 (S.D. Iowa
2009); Marenghi, 893 F. Supp. at 91–97; Commonwealth v.
Asenjo, 82 N.E.3d 966, 973–74 (Mass. 2017); Wonnum v.
State, 942 A.2d 569, 572–73 (Del. 2007); State v. Williams,
937 P.2d 1052, 1058 (Wash. 1997) (en banc). But see United
States v. Willis, 38 F.3d 170 (5th Cir. 1994); State v. Richter,
424 P.3d 402 (Ariz. 2018); State v. B.H., 870 A.2d 273 (N.J.
2005).

   This analysis of BWS as applied to duress also comports
with the way courts have long viewed self-defense, which is
similar to duress in that both defenses “require a defendant to
demonstrate that she acted reasonably in response to a
24                UNITED STATES V. LOPEZ

reasonable fear of death or bodily injury.” Marenghi, 893 F.
Supp. at 95; see Nwoye, 824 F.3d at 1138 (“Our conclusion
is further supported by the decisions of the vast majority of
courts that have long held that expert testimony on battered
woman syndrome can be relevant in the analogous context of
self-defense.”); Johnson, 956 F.2d at 900 (“The majority of
state courts that have considered the issue [of BWS] have
admitted expert testimony as to the syndrome on behalf of a
woman contending that she acted in self-defense.”); see also
see State v. Curley, No. 2016-KP-1708, 2018 WL 3154627,
at *8 (La. June 27, 2018); Commonwealth v. Pike, 726 N.E.2d
940, 948 (Mass. 2000); Boykins v. State, 995 P.2d 474,
476–79 (Nev. 2000); People v. Humphrey, 921 P.2d 1, 8–9
(Cal. 1996); People v. Wilson, 487 N.W.2d 822, 823–24
(Mich. Ct App. 1992).

     In People v. Humphrey, the California Supreme Court
concluded that, by admitting BWS evidence in a self-defense
trial, it was “not changing the standard from objective to
subjective, or replacing the reasonable ‘person’ standard with
a reasonable ‘battered woman’ standard.” 921 P.2d at 9.
Rather, “[t]he jury must consider [a] defendant’s situation
and knowledge, which makes the evidence relevant, but the
ultimate question is whether a reasonable person, not a
reasonable battered woman, would believe in the need to kill
to prevent imminent harm.” Id. (first emphasis added). As
with duress, “objective reasonableness” for self-defense
“must view the situation from the defendant’s perspective.”
Id. at 8 (emphasis in original). “As violence increases over
time, and threats gain credibility, a battered person might
become sensitized and thus able reasonably to discern when
danger is real and when it is not.” Id. at 9. “The cyclical
nature of an intimate battering relationship enables a battered
spouse to become expert at recognizing the warning signs of
                  UNITED STATES V. LOPEZ                    25

an impending assault from her partner—signs frequently
imperceptible to outsiders.” Id. at 17 (Brown, J., concurring)
(emphasis added) (quotation marks and citation omitted).
Thus, “[a]lthough a jury might not find the appearances
sufficient to provoke a reasonable person’s fear, they might
conclude otherwise as to a reasonable person’s perception of
the reality when enlightened by expert testimony on the
concept of hypervigilance.” Id. (emphasis in original).

    On balance, we are persuaded that expert testimony on
how BWS can cause individuals to become hypervigilant to
impending harm does not, as the Fifth Circuit perceives, seek
to alter the duress defense’s reasonable-person standard. See
Willis, 38 F.3d at 175. The question is still whether or not “a
person of reasonable firmness in [the defendant’s] situation
would have been unable to resist.” MODEL PENAL CODE
§ 2.09(1) (1985) (emphasis added). We acknowledge,
however, that the “‘snapshot’ of circumstances” shown to the
jury is not limited to just those circumstances existing
immediately prior to the commission of the crime. Marenghi,
893 F. Supp. 94. This court has long recognized that a
defendant’s particular situation includes consideration of past
experiences. See Johnson, 956 F.2d at 898 (“Fear which
would be irrational in one set of circumstances may be
well-grounded if the experience of the defendant with those
applying the threat is such that the defendant can reasonably
anticipate being harmed on failure to comply.” (emphasis
added)).

     Moreover, BWS evidence is compatible with assessing
whether a defendant had a reasonable opportunity to escape
from the coercing party. As seen above, this inquiry often
focuses on why the defendant did not call the police at the
first opportunity. See, e.g., Kuok, 671 F.3d at 949;
26                UNITED STATES V. LOPEZ

Contento-Pachon, 723 F.2d at 694; see also Nwoye, 824 F.3d
at 1133. Experts on BWS, however, have explained that:

       The battered woman’s perception of viable
       options for stopping the violence and abuse by
       any means is not only shaped by her own
       prior experience with violence, but also
       influences her future actions in response to
       violence. The perception or understanding of
       whether there are options available that would
       end the violence is based largely on what has
       actually been learned through experience.

Mary Ann Dutton, Understanding Women’s Responses to
Domestic Violence: A Redefinition of Battered Woman
Syndrome, 21 HOFSTRA L. REV. 1191, 1219 (1993). For
example, a woman may “‘learn[]’ during childhood that the
police [are] not a viable option to stop the violence even in an
immediate situation” if she “observed her mother call the
police on many occasions when her father beat her mother,
only to hear them say that since the situation was ‘a
domestic,’ they could not intervene.” Id. at 1220. Indeed, an
ineffective attempt to seek help will likely amplify a woman’s
risk of being harmed. See id. at 1119–20; see also Humphrey,
921 P.2d at 3 (“[M]any battered women remain in the
relationship because of lack of money, social isolation, lack
of self-confidence, inadequate police response, and a fear
(often justified) of reprisals by the batterer.”).

    Because an “assessment of the reasonableness of a
defendant’s actions must take into account the defendant’s
‘particular circumstances,’” Nwoye, 824 F.3d at 1137, a jury
may consider the defendant’s prior experience with police
response to abuse in determining whether it was reasonable
                  UNITED STATES V. LOPEZ                     27

for her not to contact them once threatened by the coercing
party. We perceive no meaningful distinction between a jury
considering such evidence and assessing whether it was
reasonable for a defendant not to contact the police due to
fear either that close family members will be harmed or that
the police are in league with the coercing party. See, e.g.,
Kuok, 671 F.3d at 949–50 (“[T]he government’s suggestion
that [the defendant] should have cooperated with the
authorities immediately upon landing in the Atlanta airport
may be unreasonable, given that [the defendant] knew his
family was still in danger of being jailed by Chinese
government officials beyond the control of U.S. authorities”);
Contento-Pachon, 723 F.2d at 694 (“The trier of fact should
decide whether one in [the defendant’s] position might
believe that some of the Bogota police were paid informants
for drug traffickers and that reporting the matter to the police
did not represent a reasonable opportunity of escape.”); see
also Nwoye, 824 F.3d at 1132 (“[The defendant] also testified
that she was afraid to report [the coercing party] to the police
because [he] had told her that he was a former FBI agent.”).

    Although a defendant may testify to how her experiences
shaped her perceptions, as the defendant was permitted to do
in this case, this lay testimony is often insufficient to
effectively mount a duress defense. “To effectively present
the situation as perceived by the defendant, and the
reasonableness of her fear,” a defendant must often
“overcome stereotyped impressions about women who
remain in abusive relationships. It is appropriate that the jury
be given a professional explanation of the battering syndrome
and its effects on the woman through the use of expert
testimony.” Humphrey, 921 P.2d at 9; see also Johnson, 956
F.2d at 899 (“Society often misinterprets the survival skills of
battered women as signs of passivity and weakness coupled
28                UNITED STATES V. LOPEZ

with an unwillingness to leave the violent relationship. A
common misunderstanding is that the battered woman’s
responses are indicative of weak character.” (citation
omitted)). We therefore conclude that expert testimony on
BWS is relevant to supporting a defendant’s argument that
she had a well-grounded fear that she would be harmed if she
failed to commit the illegal act demanded of her and that she
had no reasonable opportunity to avoid committing the crime.

    Beyond directly buttressing the elements of duress, BWS
is also relevant to the related issue of rehabilitating a
defendant’s credibility. Humphrey, 921 P.2d at 9; see also
State v. Hennum, 441 N.W.2d 793, 798 (Minn. 1989) (citing
state cases in which “courts have admitted expert testimony
on” BWS for, inter alia, “the specific purpose of bolstering
the defendant’s position and lending credibility to her version
of the facts”). Courts addressing “psychological states
analogous to BWS, such as rape trauma syndrome and child
sexual abuse accommodation syndrome, . . . have generally
held expert opinion admissible for” the purpose of
“disabus[ing] the jury of some widely held misconceptions
about [the] victims, so that it may evaluate the evidence free
of the constraints of popular myths.” Humphrey, 921 P.2d at
15 (Brown, J., concurring) (quotation marks and citations
omitted). To this end, “[j]urors faced with testimony from a
battered woman concerning her abuse and its effects may
doubt the testimony because they do not believe that a woman
subject to such abuse would stay with her abuser without
alerting police or others.” Nwoye, 824 F.3d at 1140. “Expert
testimony on battered woman syndrome” can help “dispel the
ordinary lay person’s perception that a woman in a battering
relationship is free to leave at any time.” Id. (quoting
Humphrey, 921 P.2d at 9).
                  UNITED STATES V. LOPEZ                     29

    Moreover, BWS testimony can provide juries an
understanding of why victims of abuse sometimes make
inconsistent statements or act in ways that appear
counterintuitive to a layperson. For instance, in Arcoren v.
United States, the key witness recanted at trial her prior grand
jury testimony that her husband, the defendant, had raped her.
929 F.2d 1235, 1238 (8th Cir. 1991). The government then
moved to introduce expert testimony on BWS. It argued, and
the Eighth Circuit agreed, that such evidence would aid the
jury in determining the defendant’s credibility by providing
the jury an explanation for the victim’s change in testimony.
Id. at 1239. “As the [expert] witness told the jury, [BWS] is
a psychological condition, which leads a female victim of
physical abuse to accept her beatings because she believes
that she is responsible for them, and hopes that by accepting
one more beating, the pattern will stop.” Id. at 1240. The
expert testimony thus “provided the jury with information
that would help it to determine which” version of the victim’s
“testimony to credit.” Id. Similarly, in the context of a child-
abuse prosecution, we held that expert testimony on such
abuse had “significant probative value in that it rehabilitated
(without vouching for) the victim’s credibility after she was
cross-examined about the reasons she delayed reporting and
about the inconsistencies in her testimony.” United States v.
Bighead, 128 F.3d 1329, 1331 (9th Cir. 1997). Expert
testimony on BWS could likewise rehabilitate the testimony
of a domestic-abuse victim in cases of duress, regardless of
whether she is the defendant or a government witness.

    With this understanding of the appropriate role of BWS
evidence in raising the affirmative defense of duress, we turn
to the expert evidence proffered in this case.
30                UNITED STATES V. LOPEZ

                               3

    Although Lopez’s proffer of Dr. Karp’s proposed
testimony—before trial, during trial and in her motion for a
new trial—was fairly cursory, it is evident that the testimony
would have comported with the permissible uses of BWS
evidence. Dr. Karp attested that her testimony “would have
provided the jurors with information about . . . what the
dynamics of the ‘hypervigilant’ behaviors experienced by
abused women . . . are in deciding the dangerousness of the
situation.” If jurors harbored any doubt that Lopez had a
well-grounded fear that Karaca would harm her and her
family if she failed to purchase a gun for him, this testimony
may have helped them understand why she “accurately
perceive[d] the seriousness of the situation before another
person who had not been repeatedly abused might recognize
the danger.” Nwoye, 824 F.3d at 1137 (citation omitted).

    Moreover, Dr. Karp’s testimony would have supported
Lopez’s contention that she had no reasonable opportunity to
escape from Karaca. Lopez testified at trial that her
stepfather beat her, her mother, and her sisters on a near daily
basis and also sexually assaulted her. The police would often
“take the report and leave,” and after one of the few occasions
they arrested her stepfather, “he was out the next day” and
“broke into the house.” Lopez attributed these experiences to
why she decided not to call the police after Karaca threatened
her, explaining that she feared they would not help her and
that Karaca would discover that she had called them. The
government attempted to assail this point throughout its
closing argument, contending that Lopez’s fear “just doesn’t
make sense” and referring to her explanation as “really
incredible.” Dr. Karp, however, attested that Lopez’s past
trauma “may have influenced [Lopez’s] feelings when she did
                  UNITED STATES V. LOPEZ                       31

not seek the help of the police, given her own trauma history
of being sexually abused by her step-father and the police
never protecting her.” We, of course, offer no opinion as to
whether a jury would believe Lopez or, as the government
argues, find her “really incredible,” but that is the jury’s role.
Kuok, 671 F.3d at 950. This proposed testimony would have
therefore aided the jury in assessing the reasonableness of
Lopez’s decision to buy Karaca the gun and not call the
police. See Nwoye, 824 F.3d at 1139 (“[The defendant] may
have reasonably believed that reporting [the coercing party]
to the police (or others) would have been unlikely to result in
his immediate arrest and would have therefore placed her at
greater risk in the interim. Thus, [her] testimony concerning
[his] abuse, supplemented by expert testimony on battered
woman syndrome, would have constituted ‘sufficient
evidence from which a reasonable jury could find’ for [the
defendant] on a theory of duress.”).

    Similarly, Dr. Karp’s testimony could have rehabilitated
Lopez’s credibility in light of the government’s contention
that Lopez complied with Karaca, not out of fear of him, but
to keep her “relationship [with him] alive[] [and] to keep her
contact with Karaca ongoing.” Indeed, the government
highlighted the fact that, when confronted by her probation
officer, Lopez referred to Karaca as “my man,” asserting that
this was why she bought the gun. This is precisely the type of
behavior that might appear outwardly inconsistent with being
a victim of domestic violence but can be placed in context
through expert testimony “as to the dynamics involved in
Battered Woman Syndrome and why Battered Women
remain with abusive men.”

    We garner from the district court’s series of oral rulings
on the admissibility of Dr. Karp’s testimony that the court
32                    UNITED STATES V. LOPEZ

perceived the question of admitting the BWS evidence as
“close,” but ultimately concluded that it was categorically
irrelevant to Lopez’s duress defense. In light of the foregoing
discussion, this was an error of law, which constitutes an
abuse of discretion. United States v. Finley, 301 F.3d 1000,
1007 (9th Cir. 2002). “A non-constitutional error requires
reversal unless there is a ‘fair assurance’ of harmlessness, or
stated another way, unless ‘it is more probable than not that
the error did not materially affect the verdict.’”7 United
States v. Torres, 794 F.3d 1053, 1063 (9th Cir. 2015)
(quoting United States v. Seschillie, 310 F.3d 1208, 1214 (9th
Cir. 2002)). The government argues that the exclusion of Dr.
Karp’s testimony was harmless, contending that it would
have been cumulative of Lopez’s own testimony about her
past abuse and its effect on her decisions.8 But as discussed


     7
        Lopez argues that the exclusion of Dr. Karp’s testimony prevented
her from raising a complete defense and thus amounted to constitutional
error, which requires “the Government [to] convince[] us that the error
was harmless beyond a reasonable doubt.” United States v. Stever, 603
F.3d 747, 757 (9th Cir. 2010). Because we find sufficient prejudice under
the less onerous standard for non-constitutional errors, we need not reach
this issue.
     8
        The government also briefly argues that the testimony should be
excluded under Federal Rule of Evidence 403 as unfairly prejudicial
because it would “likely . . . elicit a sympathetic emotional response in the
jury that would have affected their verdict.” We have cautioned, however,
“that the exclusion of evidence offered by the defendant in a criminal
prosecution under Rule 403 is ‘an extraordinary remedy to be used
sparingly.’” United States v. Haischer, 780 F.3d 1277, 1281 (9th Cir.
2015) (quoting United States v. Mende, 43 F.3d 1298, 1302 (9th Cir.
1995)). Lopez had already testified to the physical and sexual abuse
inflicted by her stepfather. The proposed expert testimony would have
merely explained how this abuse affected her interactions with Karaca and
the police. We perceive no undue prejudice. In any event, that is a matter
for the district court to decide.
                  UNITED STATES V. LOPEZ                      33

above, expert testimony on BWS serves an important role in
helping dispel many of the misconceptions regarding women
in abusive relationships. Such evidence was vital to Lopez’s
defense, which hinged on persuading the jury that she acted
only out of an objectively reasonable fear. We will therefore
vacate Lopez’s conviction on all counts and remand for a new
trial.

                             ***

    We hold that expert testimony on BWS is not
categorically excludable and may be relevant to a defense of
duress. We understand that our opinion leaves open many
questions concerning the proper scope of an expert’s
testimony on BWS. These questions will have to be
addressed in the first instance by the district court.

                               B

    Finally, we turn to Lopez’s argument that the district
court erred in excluding the tape of her complete interview
with the ATF agents as inadmissable hearsay. Lopez moved
the district court several times before and during trial to admit
the entire interview, raising numerous theories of
admissibility. In her motion for a new trial, Lopez again
argued that the entire taped interview should have been
admitted. She contended that the ATF agents’ statements
were non-hearsay because she offered them to show their
effect on her as the listener rather than for the truth of the
matter asserted. For instance, one of the agents told Lopez
during the interview that Karaca “is not gonna touch you. He
has no power in here. He is gonna be in jail or dead within a
week.” Lopez argued, as she does on appeal, that such
statements would not have been offered to prove that Karaca
34                UNITED STATES V. LOPEZ

could not harm her in jail, but rather to show that the
statements had the effect of making her feel safe, which
therefore led to her telling the agents about Karaca’s threats.
Lopez contended that this evidence would have helped her
counter the government’s argument at trial that the impact of
spending a night in jail led to her fabricating a story of acting
under duress the very next day. In a brief oral ruling, the
court denied the motion for a new trial, merely commenting
as to this issue that the statements were “self-serving
hearsay.”

    A district court’s evidentiary rulings are reviewed for
abuse of discretion, United States v. Beydler, 120 F.3d 985,
987 (9th Cir. 1997), as is its denial of a motion for a new trial,
United States v. King, 660 F.3d 1071, 1076 (9th Cir. 2011).
“As a general rule, a party is prohibited from introducing a
statement made by an out-of-court declarant when it is
offered at trial to prove the truth of the matter asserted.”
Torres, 794 F.3d at 1059. Accordingly, an out-of-court
statement is not hearsay if offered for any purpose other than
the truth of whatever the statement asserts. See United States
v. Sanchez-Lopez, 879 F.2d 541, 554 (9th Cir. 1989). One
common application of this principle is admitting a
declarant’s out-of-court statement for the purpose of
establishing what effect it had on the listener. See, e.g.,
United States v. Payne, 944 F.2d 1458, 1472 (9th Cir. 1991);
2 MCCORMICK ON EVIDENCE § 249 (7th ed. 2016) (providing
examples).

    Lopez is correct that the ATF agents’ statements would be
non-hearsay if considered only in the context of assessing
their impact on Lopez—i.e., convincing her that it was safe
to speak to the agents about Karaca. This conclusion is
underscored by the fact that there would be little relevance to
                     UNITED STATES V. LOPEZ                             35

the truth of the agents’ statements that Karaca could not harm
Lopez while she was in jail. In contrast, the non-hearsay
application of these statements would be relevant to rebutting
the government’s argument that Lopez’s night in jail
convinced her to fabricate her duress story.

    Nonetheless, the district court did not err in excluding this
evidence because Lopez consistently sought to introduce the
video of the entire interview. This evidence would have
undoubtedly consisted nearly exclusively of hearsay
statements, including those made by Lopez.9 There was no
abuse of discretion.

                         III. CONCLUSION

    The district court abused its discretion in categorically
excluding Lopez’s expert witness on Battered Woman
Syndrome. Because we find that this error prejudiced her
defense, we VACATE her conviction on all counts and
REMAND for a new trial.




    9
       Lopez has not argued on appeal that her statements would be non-
hearsay (e.g., under the exclusion for prior consistent statements) or would
fall under a hearsay exception.
36                UNITED STATES V. LOPEZ

RAWLINSON, Circuit Judge, dissenting:

     I respectfully dissent. Although I absolutely support the
use of expert testimony on Battered Woman Syndrome in
appropriate circumstances, I cannot say that the able district
court judge in this case abused his discretion in determining
that the testimony was not admissible in the context of
establishing a duress defense, as opposed to the usual context
of its admission - to establish self-defense.

    We start from the premise that we owe deference to the
district court’s evidentiary rulings, particularly in the realm
of expert testimony. See Saravia v. Sessions, 905 F.3d 1137,
1141 (9th Cir. 2018) (“Abuse-of-discretion review is highly
deferential to the district court. . . .) (citation omitted); see
also Skidmore v. Led Zeppelin, 905 F.3d 1116, 1136 (9th Cir.
2018) (“District courts have broad discretion in making
evidentiary rulings, including whether to allow expert
testimony. . . .) (citation and internal quotation marks
omitted).

    A district court abuses its discretion if it commits an error
of law or “reaches a result that is illogical, implausible, or
without support in the inferences that may be drawn from the
record.” Kode v. Carlson, 596 F.3d 608, 612 (9th Cir. 2010)
(citation omitted); see also Mujica v. Airscan, Inc., 771 F.3d
580, 589 (9th Cir. 2017) (same). If the district court commits
no error of law “[t]he abuse of discretion standard requires us
to uphold a district court determination that falls within a
broad range of permissible conclusions.” Kode, 596 F.3d at
612 (citation omitted). In my view, the district court’s
decision to exclude the evidence was based on such a
“permissible conclusion” that the evidence was inadmissible.
Id.
                  UNITED STATES V. LOPEZ                     37

    The proposed testimony from Dr. Cheryl Karp focused on
the defendant’s history of having been “sexually abused by
her step-father and the police never protecting her.”
However, our precedent has not characterized evidence of
this nature as relevant to a duress defense.

    In United States v. Homick, 964 F.2d 899, 905 (9th Cir.
1992), we recognized that the battered woman defense “is a
species of the defense of duress.” In that case, the defendant
sought to have expert testimony admitted to establish that her
ex-husband, who was charged with the murder of the victims,
coerced her into participating in the charged offenses through
“his complete domination over her.” Id. at 902, 905. We
ultimately concluded that any error in excluding the proffered
expert testimony was harmless because the two recorded
telephone conversations between the defendant and her ex-
husband reflected ready acquiescence, with “nothing
implicitly or explicitly threatening about either conversation.”
Id. at 906.

    Notably, in Homick we addressed battered woman
syndrome in the context of a defense tethered to the co-
perpetrator, who was alleged to be the duressor. See id. at
902, 905. Similarly, in United States v. Johnson, 956 F.2d
894 (9th Cir. 1992), superseded on other grounds in Martinez
v. Martinez, 369 F.3d 1076, 1089 (9th Cir. 2004), we
considered the duress defense in the context of women
convicted of drug offenses, who asserted that the drug
kingpin for whom they worked abused and “psychologically
threatened” them. Id. at 901–02. We phrased the issue in the
following manner: “The question, relevant to the defense of
duress in the cases before us, is whether a special
vulnerability to fear—a vulnerability not produced by those
persons causing the defendant’s criminal action—may be
38                UNITED STATES V. LOPEZ

taken into account.” Id. at 898. We resolved the issue by
answering the question in the negative: “As a defense to a
charge of criminal conduct, such subjective vulnerability has
not been admitted.” Id. (emphasis added).

    In other words, we held in Johnson that evidence of
subjective vulnerability “not produced by” the named
duressor is not admissible to establish the affirmative defense
of duress. Id. Rather, such evidence may be used at
sentencing. See id. (“[A] purely subjective element that
cannot be taken into account in determining criminal liability
may be taken into account in sentencing. . . .”) (citations
omitted).

    The real takeaway from our holding in Johnson is that the
expert testimony addressing Battered Woman Syndrome must
address vulnerability “produced by” the named duressor. Id.
And that holding, in my view, solidifies why the district court
in this case acted within its discretion by excluding the
proffered expert testimony. As discussed, the record reflects
only that the testimony would focus on the defendant’s
history of having been “sexually abused by her step-father
and the police never protecting her.” Because her step-father
was not the named duressor for the crime for which she was
on trial, our reasoning in Johnson rendered the district court’s
exclusion of the proffered evidence a “permissible
conclusion” under our precedent. Kode, 596 F.3d at 612.

    The majority seeks to avoid our holding in Johnson by
expressing its “unwilling[ness] to read Johnson as
establishing a categorical bar on [Battered Woman
Syndrome] evidence in support of a duress defense at trial.”
Majority Opinion, p.18. But Johnson does not purport to
establish a categorical bar on Battered Woman Syndrome
                     UNITED STATES V. LOPEZ                           39

evidence. Rather, it limits admissibility of that evidence to
circumstances where the individual producing the
vulnerability to duress is the same as the named duressor for
the offense being defended. See Johnson, 956 F.2d at 898.
And as a three-judge panel, we are bound to follow the
precedent of our court, no matter how unwilling we may be
to hew to our past decisions, or how unpalatable the result
may be. See Lair v. Bullock, 798 F.3d 736, 747 (9th Cir.
2015), as amended (“[W]e are bound by a prior three-judge
panel’s published opinions . . .”) (citing Miller v. Gammie,
335 F.3d 889, 892–93 (9th Cir. 2003 (en banc)).

     The majority also relies on Homick to bolster its disregard
of our analysis in Johnson. See Majority Opinion, pp. 18–19,
39. But as the majority must acknowledge, “Homick . . . adds
little clarity to the proper role of [Battered Woman
Syndrome] evidence at trial . . .” Majority Opinion, p.19.
Indeed, other than a cf. citation to Johnson, the panel in
Homick did not grapple at all with the analysis in Johnson.
Rather, the Homick panel resolved the issue by noting that the
facts in Homick did not “fall within the scope of any
reasonable approach to the battered woman defense, no
matter how we modify the traditional duress standards.” 964
F.2d at 905–906 (emphasis added). Nevertheless, it is notable
that the Homick case fit within the parameters of the Johnson
analysis: a battered woman defense tethered to the alleged
duressor. See Homick, 964 F.2d at 902, 905.

     The only other circuit to substantively address this issue
is the Fifth Circuit.1 In United States v. Willis, 38 F.3d 170,


    1
      The majority opinion cites to a case from the D.C. Circuit, United
States v. Nwoye, 824 F.3d 1129 (D.C. Cir. 2016). However, that case
addressed the issue in the context of a claim of ineffective assistance of
40                   UNITED STATES V. LOPEZ

176 (5th Cir. 1994), the Court relied on our Johnson decision
to hold that subjective evidence of vulnerability is irrelevant
to the duress defense in determining criminal liability.
Admittedly, the Fifth Circuit did not acknowledge our
explanation that the evidence attesting to subjective
vulnerability is only subjective when the “vulnerability is not
produced by those persons causing the defendant’s criminal
action.” Johnson, 956 F.2d at 898. Nevertheless, the analysis
is consistent with Johnson because the Fifth Circuit similarly
focused on the irrelevance of subjective evidence in meeting
the objective standard required to establish a duress defense.
See Willis, 38 F.3d at 175.

    The expert testimony proffered by the defendant in this
case hinged on the childhood abuse suffered by the defendant
at the hands of her step-father. In an affidavit, Dr. Karp
described how she would have testified:

             My testimony would have provided the
         jurors with information about the cycle of
         violence, how battered women behave when
         under duress, and what the dynamics of the
         “hyper-vigilant” behaviors experienced by
         abused women, as part of the dynamics of
         PTSD, are in deciding the dangerousness of
         the situation.




counsel, and says nothing more than that Battered Woman Syndrome
evidence “would have entitled [the defendant] to a jury instruction on
duress.” Id. at 1135. Nothing about that statement is inconsistent with our
analysis in Johnson, especially considering that the batterer and the
duressor were one and the same in Nwoye. See id. at 1131.
                 UNITED STATES V. LOPEZ                    41

           My testimony would also have given the
       jury an opportunity to hear from an expert on
       Trauma and how that may have influenced
       [defendant’s] feelings when she did not seek
       the help of the police, given her own trauma
       history of being sexually abused by her step-
       father and the police never protecting her.
       [Defendant] felt they would not protect her or
       believe her, given her prior childhood history
       of trauma and never being “heard” or
       “protected” by law enforcement. The jury
       should have been given an explanation by an
       expert to understand how [Defendant’s]
       childhood abuse influenced her decision-
       making.

    It is enlightening to consider what the expert did say in
her affidavit and what she did not say. She did say that the
source of Defendant’s PTSD was her step-father. She did not
say that the source of her PTSD was the named oppressor. In
fact, the named oppressor was not mentioned once in the
expert’s affidavit. She did pinpoint the time of the trauma as
Defendant’s childhood. She did not point to any trauma
during adulthood. Clearly, the focus of the expert was the
defendant’s childhood, specifically the sexual abuse inflicted
upon the defendant when she was a child. This is precisely
the type of “subjective vulnerability” evidence that Johnson
held was not relevant to a duress offense. See 956 F.2d at
898.

    I am not persuaded by the cases cited by the majority,
particularly in view of the binding precedent in this circuit
that supports the decision of the district court.
42                UNITED STATES V. LOPEZ

    In Dando v. Yukins, 461 F.3d 791 (6th Cir. 2006), the
admissibility of similar evidence was decided in the context
of a claim of ineffective assistance of counsel, see id. at 798.
The Sixth Circuit concluded that defense counsel “failed . . .
to adequately investigate the availability of a duress defense
and the related possibility that [the defendant] suffered from
Battered Women’s Syndrome.” Id. However, this Sixth
Circuit case actually fits within the holding of Johnson,
inasmuch as the defendant in Dando asserted that her co-
perpetrator and duressor were one and the same. See id.; see
also Johnson, 956 F.2d at 898 (explaining that the proffered
expert testimony must address vulnerability “produced by”
the duressor to be relevant). In any event, the Sixth Circuit
expressly noted that the issue of allowing evidence of
Battered Woman Syndrome to establish a duress defense had
not been “addresse[d] either way” under Michigan law. See
Dando, 461 F.3d at 801. This case absolutely does not
support a conclusion that the district court in our case abused
its discretion in disallowing the proffered testimony.
Similarly, the non-binding district court case of United States
v. Ramirez, No. 10-344 (PG), 2012 WL 733973 at *1
involved a co-perpetrator who was also the named duressor,
as did the non-binding cases of United States v. Ceballos, 593
F. Supp. 2d 1054, 1060–63 (S.D. Iowa 2009); and United
States v. Marenghi, 893 F. Supp. 85, 97 (D. Maine 1995).

    The non-binding state court cases are also singularly
unpersuasive because they rely upon state statutes specifically
addressing the admissibility of evidence establishing Battered
Woman Syndrome. See Commonwealth v. Asenjo, 82 N.E.3d
966, 973 (Mass. 2017) (“G.L.C. 233 § 23F, provides the
defendant the statutory right to present [evidence of Battered
Woman Syndrome]”); see also Wonnum v. State, 942 A.2d
569, 573 (Del. 2007) (referencing Del. Code §§ 303 and 304);
                  UNITED STATES V. LOPEZ                    43

State v. Williams, 937 P.2d 1052, 1058 (Wash. 1997) (en
banc) (involving a statutory duress defense and a co-
perpetrator who was also the named duressor). Importantly,
the Supreme Court of Arizona, the state where Lopez
committed her crime, has recently ruled that similar expert
testimony is not admissible under Arizona law. See State v.
Richter, 424 P.3d 402, 404 (Ariz. 2018).

    In sum, none of the non-binding cases relied upon by the
majority, singly or in combination, are sufficiently persuasive
that the district court was compelled to admit the proffered
expert testimony. This is especially true considering that the
district court’s decision fit squarely within our binding
precedent, as the proffered testimony was not linked by the
expert to the asserted duressor. See Johnson, 956 F.2d at 898
(explaining that the proffered expert testimony must address
vulnerabilities that are “produced by” the duressor). And the
district court’s decision was consistent with precedent from
the highest court in the state where the crime was committed.
See Richter, 424 P.3d at 404.

    Under the deferential abuse of discretion standard of
review, it cannot be fairly said that the district court
committed an error of law, because its decision did not run
afoul of any binding precedent, and the non-binding
precedent relied on by the majority was singularly
unpersuasive. Indeed, the district court’s decision was
actually consistent with Ninth Circuit precedent and Arizona
precedent. Largely for the same reason, the district court’s
decision was not “illogical, implausible, or without support in
the inferences that may be drawn from the record.” Kode,
596 F.3d at 612. Rather the district court’s decision fell
“within a broad range of permissible conclusions.” Id. I
would affirm the judgment of the district court.
