                 FOR PUBLICATION
 UNITED STATES COURT OF APPEALS
      FOR THE NINTH CIRCUIT

UNITED STATES OF AMERICA,                  No. 08-10027
                Plaintiff-Appellee,
               v.                            D.C. No.
                                          CR-04-00010-ECR
JERMAINE ALONZO MITCHELL,
                                             OPINION
             Defendant-Appellant.
                                      
       Appeal from the United States District Court
                for the District of Nevada
     Edward C. Reed, Senior District Judge, Presiding

                 Argued and Submitted
       October 20, 2008—San Francisco, California

                    Filed June 23, 2009

     Before: J. Clifford Wallace, Sidney R. Thomas and
              Susan P. Graber, Circuit Judges.

                Opinion by Judge Wallace;
                Dissent by Judge Thomas




                           7499
              UNITED STATES v. MITCHELL        7501




                    COUNSEL

Dennis A. Cameron, Reno, Nevada, for the defendant-
appellant.
7502               UNITED STATES v. MITCHELL
William R. Reed, Assistant United States Attorney, Reno,
Nevada, for the plaintiff-appellee.


                          OPINION

WALLACE, Senior Circuit Judge:

   Mitchell appeals from his conviction and sentence for pos-
session with intent to distribute cocaine base in violation of 21
U.S.C. § 841(a)(1) (Count One), and possession of marijuana
in violation of 21 U.S.C. § 844 (Count Two). On Count One,
he was sentenced to a mandatory term of life imprisonment
without release and ten years of supervised release. On Count
Two, he was sentenced to a term of 90 days of imprisonment
and three years of supervised release. The sentences of
imprisonment are to run concurrently, as are the terms of
supervised release. Although Mitchell raises a number of
issues on appeal, in this opinion we deal with only his claim
that he was denied his constitutional right to an impartial jury.
We address his other arguments in a companion unpublished
disposition. The district court had jurisdiction pursuant to 18
U.S.C. § 3231. We have jurisdiction over this timely filed
appeal pursuant to 28 U.S.C. § 1291 and 18 U.S.C. § 3742.
We affirm.

                               I.

  During voir dire of prospective jurors at Mitchell’s trial, the
court engaged in the following sidebar colloquy with govern-
ment attorney Fahami, defense counsel Edwards, and a pro-
spective juror, whom we refer to here as Jane Doe:

       THE COURT: [Jane Doe], please, after we recess,
    you indicated to the courtroom deputy that you had
    some sort of — there was somebody in your family
    or some friend had had some sort of contact with
    illegal drugs, is that right?
              UNITED STATES v. MITCHELL                    7503
  PROSPECTIVE JUROR [JANE DOE]: Yes. My
— it happened about nine, ten years ago in Mexico.
One of my uncles was actually killed by a drug
dealer.

  THE COURT: Okay. How old were you then?

  PROSPECTIVE JUROR [JANE DOE]: I’m 26.

  THE COURT: Do you remember any of the cir-
cumstances involving —

  PROSPECTIVE JUROR [JANE DOE]: I was
actually here in the United States, and it happened
down in Mexico. But, it was my mom’s youngest
brother.

  THE COURT: All right. Do you think that what
happened there would affect you, in any way, in
being a fair juror in this case?

  PROSPECTIVE JUROR [JANE DOE]: Um, I
don’t think so.

  THE COURT: Well, you’re going — is that the
best you can do, or can you put that out of your
mind?

   PROSPECTIVE JUROR [JANE DOE]: Um, I
think it would be on my mind, to tell you the truth
— no, I’ll be fine. No. Actually, I’m fine.

   THE COURT: I need pretty direct assurance on
this, if you think that would cause you a problem.

  PROSPECTIVE JUROR [JANE DOE]: I think it
will, now that I think about it. I didn’t think about it
7504              UNITED STATES v. MITCHELL
    before. But now that it’s in my mind, it’s a little dif-
    ferent, I think.

      THE COURT: You think it would cause you a
    problem?

       THE COURT: You have to whisper now.

      PROSPECTIVE JUROR [JANE DOE]: Sorry. It
    didn’t affect me —

       THE COURT: You have to whisper.

       PROSPECTIVE JUROR [JANE DOE]: It did
    affect my family, so I think, yes, it will affect me.

       THE COURT: Okay. You may return to your seat.

       (Side bar with the Court and counsel:)

      THE COURT: Do counsel wish me to ask any
    additional questions of the juror? Ms. Fahami.

       MS. FAHAMI: No, Your Honor.

       THE COURT: Mr. Edwards.

       MR. EDWARDS: No, Your Honor.

      THE COURT: Do you wish — do counsel wish to
    challenge the juror?

       MR. EDWARDS: No, Your Honor.

       THE COURT: And on your side, Ms. Fahami?

       MS. FAHAMI: No, Your Honor.
                   UNITED STATES v. MITCHELL                 7505
       THE COURT: Neither counsel wishes to chal-
    lenge for cause? Well, then we’ll be able to proceed
    then. Otherwise, I was going to have to take a step
    back.

      With [sic] those questions and the answers affect
    your challenge or waiver of your first peremptory,
    Ms. Fahami?

       MS. FAHAMI: No, Your Honor.

       THE COURT: All right. Thank you.

  Jane Doe was seated as a juror. Three days later, the jury
convicted Mitchell of both counts on which he had been
indicted. On appeal, Mitchell argues that he was denied his
constitutional right to an impartial jury because Jane Doe har-
bored impermissible bias.

                               II.

   Mitchell did not move to strike Jane Doe for cause during
voir dire. Normally, where a defendant fails to raise a claim
of error at trial, we will review that claim for plain error. Fed.
R. Crim. P. 52(b) (“A plain error that affects substantial rights
may be considered even though it was not brought to the
court’s attention”); United States v. Olano, 507 U.S. 725, 731
(1993) (holding that Rule 52(b) “provides a court of appeals
a limited power to correct errors that were forfeited because
[they were] not timely raised in district court”).

   Plain error exists where (1) there is an “error,” (2) that is
“plain,” and (3) the error affects “substantial rights.” Id. at
732. An “error” is any “[d]eviation from a legal rule,” and it
is “plain” if it is “clear” or “obvious.” Id. at 732-34. An error
affects “substantial rights” if the defendant is prejudiced in
such a manner as to “affect[ ] the outcome of the district court
proceedings.” Id. at 734-35. Even where these conditions
7506               UNITED STATES v. MITCHELL
exist, a court of appeals on plain error review should reverse
a conviction only where the error “seriously affect[s] the fair-
ness, integrity or public reputation of judicial proceedings.”
Id. at 736 (internal quotation marks omitted).

   Our law is ambiguous if not in conflict as to whether this
standard of review applies to unpreserved claims of juror bias.
In United States v. Olano, 62 F.3d 1180, 1192-93 (9th Cir.
1995), we applied the plain error standard of review to a claim
of juror bias where the defendant “did not move for mistrial”
in the district court. Similarly, in United States v. Mitchell, we
limited our review of a juror bias claim on appeal to plain
error because the defendant “did not ask the [trial] court to
excuse [the challenged juror] for cause.” 502 F.3d 931, 955
(9th Cir. 2007), cert. denied, 128 S. Ct. 2902 (2008), citing
United States v. Mendoza-Reyes, 331 F.3d 1119, 1121 (9th
Cir. 2003) (per curiam), and United States v. Ross, 886 F.2d
264, 266 (9th Cir. 1989).

   However, in United States v. Sanchez-Cervantes, 282 F.3d
664, 670 (9th Cir. 2002), we held that “[w]e only review for
plain error or assess whether an error is harmless when the
error is not structural.” And in Dyer v. Calderon, 151 F.3d
970, 973 n.2 (9th Cir. 1998), this court en banc held that “the
presence of a biased juror introduces a structural defect” into
a criminal defendant’s trial. Cf. United States v. Hamilton,
391 F.3d 1066, 1071 (9th Cir. 2004) (holding that a violation
of the Sixth Amendment right to counsel at “critical stage[s]”
of criminal proceedings is not subject to plain error analysis);
but see United States v. Brown, 26 F.3d 1124, 1126 (D.C. Cir.
1994) (concluding that “plain error analysis is applicable to a
sixth amendment claim not raised at trial”).

   These latter cases, apparently in conflict with earlier deci-
sions, suggest that plain error review may not be appropriate
for unpreserved claims of juror bias. However, these cases
may also be read as merely circumscribing the scope of plain
error review with respect to such claims so that a defendant
                   UNITED STATES v. MITCHELL                7507
need not demonstrate that he was prejudiced by the presence
of the challenged juror. Dyer, 151 F.3d at 973 n.2 (“The pres-
ence of a biased juror cannot be harmless; the error requires
a new trial without a showing of actual prejudice”). We need
not resolve this ambiguity or conflict in our jurisprudence,
however, because even if plain error review does not apply,
we conclude that there was no error in the district court’s fail-
ure sua sponte to strike Jane Doe from the jury.

                              III.

   [1] The Sixth Amendment right to a jury trial guarantees
the criminally accused a fair trial by a panel of impartial
jurors. Id. at 973. Even if only one juror is unduly biased or
prejudiced, the defendant is denied this constitutional guaran-
tee. Id.; see also United States v. Plache, 913 F.2d 1375, 1377
(9th Cir. 1990) (“It is well-settled that a single partial juror
deprives a defendant of his Sixth Amendment right to a trial
by an impartial jury”).

   [2] In this case, Mitchell argues that he was denied his right
to an impartial jury because the district court failed to strike
Jane Doe as biased. To succeed on such a claim, a defendant
usually bears the burden of demonstrating that the challenged
juror was biased, and that the district court erred in failing to
strike her from the jury. United States v. Martinez-Martinez,
369 F.3d 1076, 1081-82 (9th Cir. 2004), citing United States
v. Hursh, 217 F.3d 761, 768 (9th Cir. 2000). However, where
as here, no motion was made during jury selection to dismiss
the juror in question for cause, Mitchell assumes a greater
burden: he must show that the evidence of partiality before
the district court was so indicative of impermissible juror bias
that the court was obliged to strike Jane Doe from the jury,
even though neither counsel made the request. See, e.g., Ross,
886 F.2d at 266-67 (evaluating the sufficiency of the evidence
before the district court in evaluating an unpreserved claim of
juror bias); cf. Sims v. Rowland, 414 F.3d 1148, 1155-56 (9th
Cir. 2005) (holding that due process does not require a trial
7508              UNITED STATES v. MITCHELL
court to hold an evidentiary hearing sua sponte when pres-
ented with evidence of juror bias).

                              A.

   [3] “We have analyzed juror bias under two theories —
actual bias and implied bias.” Estrada v. Scribner, 512 F.3d
1227, 1240 (9th Cir.), cert. denied, 128 S. Ct. 2973 (2008).
Actual bias is, in essence, “ ‘bias in fact’ — the existence of
a state of mind that leads to an inference that the person will
not act with entire impartiality.” United States v. Gonzalez,
214 F.3d 1109, 1112 (9th Cir. 2000), quoting United States v.
Torres, 128 F.3d 38, 43 (2d Cir. 1997). Actual bias is found
where “a prospective juror states that he can not be impartial,
or expresses a view adverse to one party’s position and
responds equivocally as to whether he could be fair and
impartial despite that view.” Fields v. Brown, 503 F.3d 755,
767 (9th Cir. 2007) (en banc).

   [4] Implied bias is “bias conclusively presumed as a matter
of law.” Gonzalez, 214 F.3d at 1111, quoting 47 Am. Jur. 2d
Jury § 266 (1995). The inquiry here is “whether an average
person in the position of the juror in controversy would be
prejudiced.” Id. at 1112, quoting United States v. Cerrato-
Reyes, 176 F.3d 1253, 1260-61 (10th Cir. 1999) (emphases
and internal quotation marks omitted). Thus, we have pre-
sumed a challenged juror’s bias “where the relationship
between a prospective juror and some aspect of the litigation
is such that it is highly unlikely that the average person could
remain impartial in his deliberations under the circum-
stances.” Tinsley v. Borg, 895 F.2d 520, 527 (9th Cir. 1990),
quoting Person v. Miller, 854 F.2d 656, 664 (4th Cir. 1988).
We have cautioned, however, that bias should be presumed
only in “extreme” or “extraordinary” cases. Tinsley, 895 F.2d
at 527, quoting Smith v. Phillips, 455 U.S. 209, 222, 223 n.*
(1982) (O’Connor, J., concurring); see also Fields, 503 F.3d
at 770 (holding that bias should be presumed only in “extreme
situations”).
                  UNITED STATES v. MITCHELL                   7509
   In Gonzalez, we applied these standards to conclude that a
juror serving in a narcotics trial displayed impermissible bias
where:

    [the juror] disclosed the fact that her ex-husband, the
    father of her daughter, dealt and used cocaine — the
    same drug and conduct at issue here. Moreover, she
    described her former husband’s drug dealing as one
    of the reasons for her relatively recent divorce and
    the break-up of her family. She admitted that the
    experience was painful. Asked three times whether
    she could put that experience aside and serve fairly
    and impartially, she never affirmatively stated that
    she could. Instead, she equivocated each time.

214 F.3d at 1113. We held that the juror’s equivocal state-
ments regarding her ability to be impartial, coupled with “the
similarity between her traumatic familial experience and the
defendant’s alleged conduct,” warranted reversal of the defen-
dant’s conviction “under either an express or implied bias the-
ory.” Id. at 1114; see also United States v. Eubanks, 591 F.2d
513, 517 (9th Cir. 1979) (per curiam) (presuming bias in a
heroin conspiracy case on the part of a juror whose children
were in prison for heroin-related crimes); United States v.
Allsup, 566 F.2d 68, 71-72 (9th Cir. 1977) (holding that bias
may be presumed from the “potential for substantial emo-
tional involvement” inherent where prospective jurors worked
for a bank, which had a branch that defendants were charged
with robbing).

   By contrast, in Fields, this court sitting en banc concluded
that the challenged juror did not harbor either actual or
implied bias, despite the fact that his wife was a victim of a
traumatic assault similar to the one involved at trial. 503 F.3d
at 764-65. During voir dire, the juror volunteered that his
“wife was assaulted and beaten, robbed, two years ago Christ-
mas.” Id. at 764. When asked if he would be able to be fair
and impartial, the juror answered in the affirmative. Id. He
7510               UNITED STATES v. MITCHELL
was subsequently empaneled on the jury with no objections
from either party. Id. On collateral review and following an
evidentiary hearing at this court’s request, we affirmed the
district court’s finding that the juror had “truthfully repre-
sented that he was impartial” during voir dire. Id. at 767.
Therefore, “there was no manifest error in the district court’s
finding that [the juror] was not actually biased.” Id.

   Fields also declined to presume bias on the part of the chal-
lenged juror, holding that “[b]eing the spouse of a rape victim
is not, in and of itself, such an ‘extreme’ or ‘extraordinary’
situation that it should automatically disqualify one from serv-
ing on a jury in a case that involves rape.” Id. at 774. In so
ruling, we emphasized that “prudence dictates that courts
[determining whether to presume bias] should hesitate before
formulating categories of relationships which bar jurors from
serving in certain types of trials.” Id. at 772, quoting Tinsley,
895 F.2d at 527; see also Tinsley, 895 F.2d at 529 (holding
that a presumption of juror bias was unwarranted where the
defendant was on trial for rape, and the challenged juror had
worked as a psychiatric social worker trained to deal with
rape victims and at one point had testified on behalf of a rape
victim).

                               B.

   [5] In this case, we conclude that the evidence of juror bias
was insufficient to require the district court to strike Jane Doe
from the jury sua sponte. When asked, “[d]o you think that
what happened [to your uncle] would affect you, in any way,
in being a fair juror in this case?” Jane Doe responded that she
did not think so. After being pressed further by the district
court, she answered, “no, I’ll be fine. No. Actually, I’m fine.”
Critically, none of the subsequent questions explicitly
returned to the theme of whether she could be a fair juror in
this case. Rather, she was asked whether she could “put that
[event] out of [her] mind,” and whether “[the event] would
cause you a problem.” To these inquiries, Jane Doe answered
                  UNITED STATES v. MITCHELL                7511
that the experience “did affect my family, so I think, yes, it
will affect me.”

   [6] Jane Doe’s answers were too vague and ambiguous to
have obliged the district court to strike her sua sponte for
actual bias. In response to the only question directly inquiring
into her ability to be an impartial juror, Jane Doe explicitly
stated that her uncle’s death at the hands of a drug dealer
would not affect her impartiality. Although she later stated
that her uncle’s death would “affect” her, she did not elabo-
rate on precisely how she would be affected, nor did the par-
ties ask for further clarification. Clearly, once her uncle’s
death was raised, it would be difficult for her to erase the
event from her mind; but she never stated that it would pre-
vent her from being impartial. Thus, unlike the juror in Gon-
zalez who testified that her husband’s drug dealing was a
primary reason for their eventual divorce, Jane Doe did not
indicate that her uncle’s death affected her in such a way as
to impair her ability to be impartial. The district court there-
fore did not err in failing sua sponte to strike Jane Doe for
actual bias. Cf. United States v. Alexander, 48 F.3d 1477,
1484 (9th Cir. 1995) (denying actual bias claim where a juror
affirmatively stated that she could remain impartial, despite
the fact that her statements were somewhat equivocal).

   [7] In addition, the circumstances do not warrant a pre-
sumption of bias. Mitchell was on trial for possession of mari-
juana and possession with intent to distribute cocaine base.
Jane Doe testified that her uncle was killed by a drug dealer
in Mexico some ten years prior to trial. Although drug traf-
ficking features in both Jane Doe’s personal experience and
Mitchell’s conduct, we rejected an even closer personal con-
nection as grounds for implied bias in Fields. In that case, the
challenged juror’s wife had been a victim of an assault that
was extremely similar to the conduct on trial. Yet we con-
cluded that “[i]t cannot be said that the average person in [the
challenged juror’s] position would be highly unlikely to
remain impartial.” 503 F.3d at 774.
7512               UNITED STATES v. MITCHELL
   [8] Similarly here, Jane Doe’s testimony reveals that her
uncle’s killing at the hands of a drug dealer occurred a full
decade before the trial, and in another country while she was
in the United States. Moreover, Jane Doe had no personal rec-
ollection of the circumstances of her uncle’s killing except in
the most general of terms. It is also salient that Mitchell was
not accused of any violent conduct, making it even less likely
that Jane Doe would connect him to her uncle’s killer. Thus,
this is not a case like Gonzalez, Eubanks, or Allsup, where the
challenged juror’s personal experience closely mirrored the
conduct that was on trial, or where the juror’s personal situa-
tion made the juror especially vulnerable to bias because the
case featured the same kind of conduct to which the juror was
exposed. The district court therefore did not err; the district
judge was not required to remove Jane Doe as a prospective
juror sua sponte on the theory of implied bias.

                               C.

   The dissent reads our precedents differently, concluding
that Gonzales compels reversal of Mitchell’s conviction.
However, as described above, critical distinctions lie between
Gonzales and this case. Chief among those distinctions is the
fact that the defendant in Gonzales raised his claim of juror
bias during voir dire, whereas Mitchell did not do so here. In
fact, none of the cases the dissent cites in support of its posi-
tion involves situations where, as here, the defendant failed to
raise objections to the challenged juror at trial. This distinc-
tion is crucial. We have emphasized that, “[i]n most situa-
tions, voir dire, ‘the method we have relied on since the
beginning,’ should suffice to identify juror bias.” Tinsley, 895
F.2d at 528, quoting Patton v. Yount, 467 U.S. 1025, 1038
(1984); see also Fields, 503 F.3d at 774 (“It is the role of voir
dire to ferret out [relationships evidencing juror bias], and to
develop the extent to which the juror’s ability to be impartial
in the particular case is actually, or presumptively, affected”).
Thus, “[c]hallenges for cause are the means by which partial
or biased jurors should be eliminated.” Gonzalez, 214 F.3d at
                   UNITED STATES v. MITCHELL                   7513
1111; cf. Yakus v. United States, 321 U.S. 414, 444 (1944)
(“No procedural principle is more familiar to this Court than
that a constitutional right may be forfeited in criminal as well
as civil cases by the failure to make timely assertion of the
right before a tribunal having jurisdiction to determine it”).

   [9] Here, the court properly inquired into Jane Doe’s ability
to be impartial and the parties were given an opportunity to
follow up on that line of questioning, but were apparently sat-
isfied with what they heard. Moreover, there is no allegation
that Jane Doe was dishonest in her responses to the court’s
questioning, or that she otherwise concealed material informa-
tion about her past. Cf. Fields, 503 F.3d at 773 (“[W]e have
never [presumed bias] when the juror was honest on voir
dire”). Certainly, it must be significant that neither party at the
time moved to strike Jane Doe for cause, neither attempted to
elicit additional information about her uncle’s killing to set up
a challenge, and neither exercised a peremptory challenge to
exclude her. Under these circumstances, where the evidence
of juror bias is weak, and neither party challenged the juror
for cause, it is not error for the district court to allow the juror
to serve at trial.

                                IV.

   Because we conclude that Jane Doe’s voir dire statements
were insufficient to evidence impermissible bias, we hold that
the district court did not err in failing to strike her from the
jury sua sponte. There was therefore no violation of Mitch-
ell’s Sixth Amendment right to an impartial jury. For these
reasons, and for those stated in the companion unpublished
disposition, we uphold Mitchell’s conviction and sentence.

  AFFIRMED.
7514               UNITED STATES v. MITCHELL
THOMAS, Circuit Judge, dissenting:

   A prospective juror told the court that her ability to be a fair
juror would be affected because a drug dealer had murdered
her uncle. Despite this admission, she was nevertheless
seated. Because the presence of a biased juror is structural
error requiring reversal, I respectfully dissent.

  A juror is “biased in fact” when the juror has “a state of
mind that leads to an inference that the person will not act
with entire impartiality.” United States v. Gonzalez, 214 F.3d
1109, 1112 (9th Cir. 2000) (quoting United States v. Torres,
128 F.3d 38, 43 (2nd Cir. 1997)). “Actual bias is typically
found when a prospective juror states that he can not be
impartial.” Fields v. Brown, 503 F.3d 755, 767 (9th Cir. 2007)
(en banc). Because an impartial jury is so fundamental to the
Sixth Amendment right to a fair trial, “[d]oubts regarding bias
must be resolved against the juror.” Gonzalez, 214 F.3d at
1114 (quoting Burton v. Johnson, 948 F.2d 1150, 1158 (10th
Cir. 1991)).

   Here, the trial judge began by asking the juror whether she
thought that her experience would affect her “in any way, in
being a fair juror in this case?” After some equivocal collo-
quy, the trial judge asked for “pretty direct assurance” as to
whether her experience “would cause [her] a problem.” After
an ambiguous answer, the court pressed further, asking
directly whether the juror thought it would cause her a prob-
lem. In response, the juror finally said that the murder of her
uncle “did affect my family, so I think, yes it will affect me.”
The court then told the juror to return to her seat.

   Our case law compels the conclusion that the juror was
impermissibly biased. In Gonzales, we held that a juror was
impliedly and actually biased even though the juror never
once stated that she could not be impartial. Gonzales, 214
F.3d at 1114. The prospective juror there stated repeatedly
that she would “try” to treat the defendant fairly. Id. at 1111.
                      UNITED STATES v. MITCHELL                        7515
That was enough for us to conclude that the prospective juror
was actually biased. We held that, “[w]hen a juror is unable
to state that she will serve fairly and impartially despite being
asked repeatedly for such assurances, we can have no confi-
dence that the juror will ‘lay aside’ her biases or her prejudi-
cial personal experiences and render a fair and impartial
verdict.” Id. at 1114.

   The juror’s answers here reflect more bias than the pro-
spective juror in Gonzales. In Gonzales, the prospective juror
was at least able to state conclusively that she would try to be
impartial. Here, the juror’s final answer was that her ability to
serve as a juror would be affected by her past experience. She
could not ultimately state that she could “serve fairly and
impartially.” Id.1

   The facts of this case and Gonzales stand in stark contrast
to cases in which we have concluded that no actual or implied
bias existed. For example, in Fields, the prospective juror
responded that he would be unaffected by his prior experience
and would base his decision “strictly on the charges and the
evidence that’s presented.” 503 F.3d at 764. When the judge
followed up with: “And you would accept and follow the law
  1
   The majority attempts to distinguish Gonzales by noting that in Gon-
zales, the defendant’s counsel asked to strike the prospective juror.
Because Mitchell’s counsel did not move to strike Jane Doe, the majority
argues, Doe’s bias must have been particularly severe. The majority thus
creates two standards for juror bias depending on whether the bias was
objected to below. This argument finds no support in case law and is irrel-
evant to a structural error analysis because it conflates the standard of
review and bias analyses. The correct analysis is simpler: the presence of
a biased juror is structural error requiring automatic reversal.
   The majority additionally invokes the principle that a defendant may
forfeit a constitutional right by failing to assert the right. That rule does
not apply in cases of structural error. The Second Circuit has held that the
right to an impartial factfinder was “inherently unwaivable” because to
hold otherwise would result in “fundamentally unfair” proceedings against
the defendant. United States v. Nelson, 277 F.3d 164, 205 (2nd Cir. 2002)
(citing United States v. Fay, 300 F.2d 345, 350-51 (2d Cir. 1962)).
7516                 UNITED STATES v. MITCHELL
given to you by the court and apply it, to the best of your abil-
ity, to the facts as you determine them to be?,” the prospective
juror responded: “Definitely.” Id. The prospective juror’s
answers were clear and unambiguous, and the Fields court
rightfully had no trouble dismissing the actual bias claim.
Similarly, in United States v. Mitchell, 502 F.3d 931 (9th Cir.
2007), the juror initially indicated she thought that certain
types of crime should be punishable by death, but concluded
by saying “she could keep an open mind.” Id. at 955. Fields
and Mitchell follow the usual course of voir dire examination
in which a juror expresses some reservations, but upon ques-
tioning resolves doubt and asserts that he or she can put pre-
conceptions or prior experiences aside and impartially decide
the case based on an open-minded and fair consideration of
the applicable law and evidence. See also United States v.
Nelson, 277 F.3d 164, 202-03 (2nd Cir. 2002) (“[I]t is impor-
tant that a juror who has expressed doubts about his or her
impartiality also unambiguously assure the district court, in
the face of these doubts, of her willingness to exert truly best
efforts to decide the case without reference to the predisposi-
tions and based solely on the evidence presented at trial.”).

   In contrast, the juror in our case affirmatively concluded
that her past experience would affect her ability to be a fair
juror. Her statement did not come at the beginning of voir
dire; it came at the conclusion of her examination after the
trial court had emphasized the need for a “direct assurance”
of impartiality. “A court confronted with a colorable claim of
juror bias must undertake an investigation of the relevant facts
and circumstances.” Dyer v. Calderon, 151 F.3d 970, 974 (9th
Cir. 1998) (en banc). Moreover, “[a] court must excuse a pro-
spective juror if actual bias is discovered during voir dire.”
United States v. Allsup, 566 F.2d 68, 71 (9th Cir. 1977). In the
face of a statement that a juror’s past experience would affect
her ability to be a fair juror, the district court should not have
allowed her to sit on the jury.2
  2
   The majority cannot cite one case where a court found impartial a pro-
spective juror who ultimately concluded, as Doe did, that she was affected
by a crime similar to the one bring tried.
                   UNITED STATES v. MITCHELL                 7517
   Juror bias is structural error requiring reversal. Dyer, 151
F.3d at 973 n.2. We have long recognized that biased jurors
so infect the criminal trial process that their presence on a jury
requires automatic reversal of any verdict produced by that
jury. United States v. Hendrix, 549 F.2d 1225, 1227 (9th Cir.
1977). If even one juror is unduly biased or prejudiced or
improperly influenced, the criminal defendant is denied his
Sixth Amendment right to an impartial panel. Id.

   As the majority rightly points out, defense counsel did not
challenge the juror for cause or raise any other objection to
her empanelment. However, because juror bias is a structural
error, plain error analysis is not appropriate. United States v.
Hamilton, 391 F.3d 1066, 1071 (9th Cir. 2004) (“ ‘We only
review for plain error or assess whether an error is harmless
when the error is not structural.’ ” (quoting United States v.
Sanchez-Cervantes, 282 F.3d 664, 670 (9th Cir. 2002))).

   Additionally, although the majority correctly observes that
“[t]he principal way” trial judges normally assure an impartial
jury “is through the system of challenges exercised during
voir dire,” Allsup, 566 F.2d at 71, our case law nowhere
defines that system of challenges as the only way to achieve
an impartial jury. See Dyer, 151 F.3d at 973 (describing voir
dire only as “[o]ne important mechanism” for ensuring impar-
tiality). Trial judges have a duty to excuse a prospective juror
if bias is discovered during voir dire. Allsup, 566 F.2d at 71.
Because seating a biased juror is a structural error, reversal is
required.

  For these reasons, I respectfully dissent.
