FOR PUBLICATION

UNITED STATES COURT OF APPEALS

FOR THE NINTH CIRCUIT

ESTATE OF HENRY BARABIN;

GERALDINE BARABIN, personal

representative,

Plaintiffs-Appellees,

v.

ASTENJOHNSON, INC.,

Defendant-Appellant.

No. 10-36142

D.C. No.

2:07-cv-01454-

RSL

ESTATE OF HENRY BARABIN;

GERALDINE BARABIN, personal

representative,

Plaintiffs-Appellees,

v.

ASTENJOHNSON, INC.,

Defendant,

and

SCAPA DRYER FABRICS, INC.,

Defendant-Appellant.

No. 11-35020

D.C. No.

2:07-cv-01454-

RSL

OPINION
2 ESTATE OF BARABIN V. ASTENJOHNSON

Appeal from the United States District Court

for the Western District of Washington

Robert S. Lasnik, District Judge, Presiding

Argued and Submitted En Banc

June 25, 2013—Seattle, Washington

Filed January 15, 2014

Before: Alex Kozinski, Chief Judge, and Diarmuid F.

O’Scannlain, M. Margaret McKeown, William A. Fletcher,

Richard C. Tallman, Johnnie B. Rawlinson, Jay S. Bybee,

Milan D. Smith, Jr., N. Randy Smith, Jacqueline H.

Nguyen and Paul J. Watford, Circuit Judges.

Opinion by Judge N.R. Smith;

Partial Concurrence and Partial Dissent by Judge Nguyen

SUMMARY*

Expert Testimony

The en banc court vacated the district court’s judgment,

and remanded for a new trial based on its determination that

the district court failed to make findings of relevancy and

reliability before admitting into evidence certain expert

testimony, and that this error resulted in prejudice to the

defendant. 

* This summary constitutes no part of the opinion of the court. It has

been prepared by court staff for the convenience of the reader.
ESTATE OF BARABIN V. ASTENJOHNSON 3

The en banc court held that the district court abused its

discretion by failing to make appropriate gateway

determinations under Daubert v. Merrell Dow Pharm., Inc.,

509 U.S. 579 (1993), and Federal Rule of Evidence 702,

when it admitted expert testimony at trial. The en banc court

conducted harmless error review by asking if erroneously

admitting or excluding the evidence affected the outcome of

the trial. The en banc court held that the error was prejudicial

because the erroneously admitted evidence was essential to

the defendants’ case. 

The en banc court held that a reviewing court has the

authority to make Daubert findings based on the record

established by the district court, and overruled Mukhtar v.

California State University, 299 F.3d 1053, 1066 n.12 (9th

Cir. 2002), amended by 319 F.3d 1073 (9th Cir. 2003), to the

extent that it required that Daubert findings always be made

by the district court. The en banc court concluded that the

record before the en banc court was too sparse to determine

whether the expert testimony was relevant and reliable, and

remanded for a new trial.

Judge Nguyen, joined by Judges McKeown, W. Fletcher,

Bybee, and Watford, concurred in part and dissented in part. 

Judge Nguyen concurred in Part I of the majority’s opinion,

which concluded that the district court failed to fulfill its

gatekeeping function with regard to the expert testimony at

issue, and agreed that the court was unable to determine on

the current record whether the expert testimony was

admissible. Judge Nguyen dissented with the majority’s

application of harmless error review, and would conditionally

vacate the judgment and remand with instructions to conduct

a Daubert analysis in the first instance. 
4 ESTATE OF BARABIN V. ASTENJOHNSON

COUNSEL

Michael B. King (argued) and Emilia L. Sweeney, Carney

Badley Spellman P.S., Seattle, Washington, for DefendantAppellant AstenJohnson.

Mary H. Spillane and Daniel W. Ferm, Williams, Kastner &

Gibbs PLLC, Seattle Washington, for Defendant-Appellant

Scapa.

Cameron O. Carter, Brayton Purcell LLP, Portland, Oregon;

Philip A. Talmadge (argued) and Sidney Tribe,

Talmadge/Fitzpatrick PLLC,Tukwila, Washington; and Alan

R. Brayton, Gilbert L. Purcell, Lloyd F. LeRoy, James P.

Nevin, and Richard M. Grant, Brayton Purcell LLP, Novato,

California, for Plaintiffs-Appellees.

OPINION

N.R. SMITH, Circuit Judge:

This case requires us to once again consider the district

court’s admission of expert testimony at trial. We review the

admission of expert testimony at trial for an abuse of

discretion. Primiano v. Cook, 598 F.3d 558, 563 (9th Cir.

2010). If the district court improperly admitted the expert

testimony, we apply harmless error review to determine

whether its decision must be reversed. United States v.

Laurienti, 611 F.3d 530, 547 (9th Cir. 2010). When we find

the erroneous admission of evidence actually prejudiced the

defendant, such that the error was not harmless, the

appropriate remedy is a new trial. See United States v. 4.85

Acres of Land, 546 F.3d 613, 620 (9th Cir. 2008). Applying
ESTATE OF BARABIN V. ASTENJOHNSON 5

this well-settled precedent to the facts of this case, we vacate

the judgment and remand for a new trial.1

FACTS

Henry Barabin worked at Crown-Zellerbach paper mill

from 1968 until his retirement in 2001. In the mill, CrownZellerbach shredded logs into chips and then exposed the

chips to corrosive chemicals and high pressure to create paper

slurry. Paper slurry is ninety-nine percent water and one

percent pulp fiber. The mill produced paper by removing

water from the paper slurry. As part of that process,

machines pulled the paper through dryers. Dryer felts held

the paper against the dryers, so that the paper would dry

properly. AstenJohnson, Inc. and Scapa Dryer Fabrics, Inc.

supplied the mill with dryer felts that contained asbestos.

Barabin had a variety of jobs during the time he worked

at the mill. He started as a paper sorter, working in a

different building than where the dryers were located. He

then moved to the technical department, where he worked as

a pulp tester and a paper tester. On occasion, he worked at a

test station that was about twenty feet from the dryers. After

working in the technical department, he went to work on the

paper machines. Part of his job was to clean the dryers. 

However, these jobs were not his only exposure to the dryer

felts; he also took pieces of dryer felt home to use in his

garden.

1 Because we find the erroneous admission of expert testimony warrants

a new trial, we do not address the merits of the other arguments raised by

AstenJohnson and Scapa.
6 ESTATE OF BARABIN V. ASTENJOHNSON

In 2006, Barabin was diagnosed with pleural malignant

epithelial mesothelioma (“mesothelioma”). Mesothelioma is

a rare cancer that affects the tissue surrounding the lungs. 

Alleging that this occupational exposure to asbestos from the

dryer felts caused his mesothelioma, Henry Barabin and

Geraldine Barabin, his wife, brought suit against

AstenJohnson and Scapa.

All parties agree, and the science makes clear, that

asbestos exposure from inhaling respirable fibers can cause

mesothelioma. At trial, the parties argued over whether

exposure to the dryer felts (provided by AstenJohnson and

Scapa) substantially contributed to Barabin’s mesothelioma. 

Of necessity, the case was to be a battle of the experts. Both

parties had experts who were prepared to testify in support of

their arguments.

Two of the Barabins’ experts were Kenneth Cohen and

Dr. James Millette. Mr. Cohen had been employed in the

industrial hygiene field for several decades. He had also

taught industrial toxicology courses at a university. Dr.

Millette had been involved in asbestos related research since

1974. He published a number of articles dealing with

asbestos, including an article dealing with asbestos fiber

release from dryer felts.

Prior to trial, AstenJohnson and Scapa filed motions in

limine to exclude Mr. Cohen and Dr. Millette as expert

witnesses. AstenJohnson argued that Mr. Cohen was not

qualified to testify as an expert and that his theory was not the

product of scientific methodology. AstenJohnson and Scapa

argued that Dr. Millette’s tests were unreliable, because his

methodology was not generally accepted in the scientific

community. They also argued that the disparity between his
ESTATE OF BARABIN V. ASTENJOHNSON 7

tests and the conditions at the mill was so great that his

testimony would not help the jury. The motions also sought

to exclude testimony from any expert regarding the theory

that “every asbestos fiber is causative.”

After receiving the motions, and without a Daubert2

hearing, the district court excluded Mr. Cohen as a witness

because of his “dubious credentials and his lack of expertise

with regard to dryer felts and paper mills.” The district court

also had concerns with Dr. Millette’s testimony. Specifically,

the district court was “troubled by the marked differences

between the conditions of Dr. Millette’s tests and the actual

conditions at the [mill].” Nonetheless, the district court ruled

that Dr. Millette could testify provided the jury was informed

his tests were “performed under laboratory conditions which

are not the same as conditions at the [mill].”

As to the “everyexposure” theory, the district court found

“a strong divide among both scientists and courts” on whether

it is relevant in asbestos cases. However, “[i]n the interest of

allowing each party to try its case to the jury,” the district

court allowed the testimony.

The Barabins then filed a motion to request a pretrial

Daubert hearing regarding Mr. Cohen. At a pretrial

conference, the district court rejected the Barabins’ request

for a Daubert hearing. Instead, it reversed its decision to

exclude Mr. Cohen’s testimony. The district court’s only

explanation for why it reversed its decision was that the

Barabins “did a much better job” in their motion “of

presenting . . . the full factual basis behind Mr. Cohen

testifying and his testimony in other cases.”

 

2 Daubert v. Merrell Dow Pharm., Inc., 509 U.S. 579 (1993).
8 ESTATE OF BARABIN V. ASTENJOHNSON

At trial, numerous experts testified. Both Mr. Cohen and

Dr. Millette testified. Dr. Brodkin, another expert, also

testified for the Barabins. Part of Dr. Brodkin’s testimony

was about the “every exposure” theory. As each of these

experts testified, AstenJohnson and Scapa objected to their

testimony. The district court overruled the objections.

PROCEDURAL HISTORY

After the Barabins presented their case at trial,

AstenJohnson and Scapa filed motions for judgment as a

matter of law. AstenJohnson and Scapa believed they were

entitled to judgment as a matter of law, because the Barabins

had failed to show that their companies had manufactured the

dryer felts to which Barabin had been exposed. In the

alternative, they argued that the Barabins had failed to

demonstrate a causal link between the dryer felts and

Barabin’s mesothelioma. The district court denied the

motions. AstenJohnson and Scapa renewed their motions

after closing arguments. The district court denied the

motions again.

After deliberations, the jury found in favor of the

Barabins and awarded damages totaling $10,200,000. The

district court granted AstenJohnson’s and Scapa’s motions to

vacate the judgment and scheduled a reasonableness hearing. 

The district court found the damages award to be reasonable,

offset the judgment by a total of $836,114.61,3and entered

3 The Barabins had previously settled with a number of third parties.

Washington law requires the court to offset the judgment by the amount

ofsuch settlements, unless the settlements were unreasonable. See Wash.

Rev. Code § 4.22.060(2).
ESTATE OF BARABIN V. ASTENJOHNSON 9

judgment in favor of the Barabins in the amount of

$9,373,152.12.

Both Scapa and AstenJohnson then filed motions for a

new trial or, in the alternative, for a remittitur. One of the

grounds on which Scapa and AstenJohnson sought a new trial

was the improper admission of expert testimony. The district

court denied the motions in their entirety.

AstenJohnson and Scapa filed timely notices of appeal. 

A three-judge panel consolidated the appeals. It unanimously

held that the district court abused its discretion by failing to

make the necessary relevancy and reliability findings under

Daubert. The panel remanded for a new trial pursuant to

Mukhtar v. California State University, 299 F.3d 1053 (9th

Cir. 2002), amended by 319 F.3d 1073 (9th Cir. 2003). The

Barabins petitioned this Court to rehear the case en banc, and

a majority of non-recused active judges voted to rehear the

case.

STANDARDS OF REVIEW

“A district court’s evidentiary rulings should not be

reversed absent clear abuse of discretion and some

prejudice.” Grand Canyon Skywalk Dev., LLC v. ‘Sa’ Nyu

Wa Inc., 715 F.3d 1196, 1202 (9th Cir. 2013) (internal

quotations and citation omitted). However, we review de

novo the “construction or interpretation of . . . the Federal

Rules of Evidence, including whether particular evidence

falls within the scope of a given rule.” United States v.

Durham, 464 F.3d 976, 981 (9th Cir. 2006) (citations

omitted). A ruling on a motion for new trial “will be

overturned on appeal only for abuse of discretion.” Kode v.

Carlson, 596 F.3d 608, 611 (9th Cir. 2010) (citation omitted).
10 ESTATE OF BARABIN V. ASTENJOHNSON

DISCUSSION

I.

Rule 702 of the Federal Rules of Evidence governs

admission of expert testimony in the federal courts:

If scientific, technical, or other specialized

knowledge will assist the trier of fact to

understand the evidence or to determine a fact

in issue, a witness qualified as an expert by

knowledge, skill, experience, training, or

education, may testify thereto in the form of

an opinion or otherwise, if (1) the testimony is

based upon sufficient facts or data, (2) the

testimony is the product of reliable principles

and methods, and (3) the witness has applied

the principles and methods reliably to the

facts of the case.

Fed. R. Evid. 702 (2010).4 We have interpreted Rule 702 to

require that “[e]xpert testimony . . . be both relevant and

reliable.” United States v. Vallejo, 237 F.3d 1008, 1019 (9th

Cir. 2001). Relevancy simply requires that “[t]he evidence

. . . logically advance a material aspect of the party’s case.” 

Cooper v. Brown, 510 F.3d 870, 942 (9th Cir. 2007).

The issue here is reliability: whether an expert’s

testimony has “a reliable basis in the knowledge and

experience of the relevant discipline.” Kumho Tire Co., Ltd.

v. Carmichael, 526 U.S. 137, 149 (1999) (citation and

 

4

 The trial in this case took place before the Federal Rules of Evidence

were restyled in 2011.
ESTATE OF BARABIN V. ASTENJOHNSON 11

alterations omitted). The “evidentiary reliability [is] based

upon scientific validity.” Daubert, 509 U.S. at 590 n.9. We

are concerned “not [with] the correctness of the expert’s

conclusions but the soundness of his methodology.” 

Primiano v. Cook, 598 F.3d 558, 564 (9th Cir. 2010)

(citations and quotations omitted). The duty falls squarely

upon the district court to “act as a ‘gatekeeper’ to exclude

junk science that does not meet Federal Rule of Evidence

702’s reliability standards.” Ellis v. Costco Wholesale Corp.,

657 F.3d 970, 982 (9th Cir. 2011).

The reliability inquiry is “a flexible one.” Kumho Tire,

526 U.S. at 150. The Supreme Court has suggested several

factors that can be used to determine the reliability of expert

testimony: “1) whether a theory or technique can be tested; 2)

whether it has been subjected to peer review and publication;

3) the known or potential error rate of the theory or

technique; and 4) whether the theory or technique enjoys

general acceptance within the relevant scientific community.” 

United States v. Hankey, 203 F.3d 1160, 1167 (9th Cir. 2000)

(citing Daubert, 509 U.S. at 592–94). However, whether

these specific factors are “reasonable measures of reliability

in a particular case is a matter that the law grants the trial

judge broad latitude to determine.” Kumho Tire, 526 U.S. at

153.

The trial judge also has broad latitude in determining the

appropriate form of the inquiry. See United States v.

Alatorre, 222 F.3d 1098, 1102 (9th Cir. 2000) (“Nowhere . . .

does the Supreme Court mandate the form that the inquiry

into relevance and reliability must take.”). While pretrial

“Daubert hearings” are commonly used, see, e.g., United

States v. Lukashov, 694 F.3d 1107, 1112 (9th Cir. 2012), they
12 ESTATE OF BARABIN V. ASTENJOHNSON

are certainly not required, United States v. Jawara, 474 F.3d

565, 582 (9th Cir. 2006).

Nevertheless, Rule 702 “clearly contemplates some

degree of regulation of the subjects and theories about which

an expert may testify.” Daubert, 509 U.S. at 589 (emphasis

added). Applying these principles to the facts before us, we

find the district court abused its discretion by failing to make

appropriate determinations under Daubert and Federal Rule

of Evidence 702.

The district court first excluded Mr. Cohen’s testimony

based on his “dubious credentials and lack of expertise.” The

district court’s only explanation for reversing its decision,

without a Daubert hearing or findings, was, “I think the

plaintiffs did a much better job of presenting to me the full

factual basis behind Mr. Cohen testifying and his testimony

in other cases.” Absent from the explanation is any

indication that the district court assessed, or made findings

regarding, the scientific validity or methodology of Mr.

Cohen’s proposed testimony. Therefore, the district court

failed to assume its role as gatekeeper with respect to Mr.

Cohen’s testimony.

The district court also failed to act as gatekeeper for Dr.

Millette’s testimony. After acknowledging various

arguments as to whether the testimony was admissible, the

district court concluded that it could be admitted, so long as

the jury was informed of the “marked differences” between

conditions of the tests and the actual conditions of the mill. 

Rather than making findings of relevancy and reliability, the

district court passed its greatest concern about Dr. Millette’s

testimony to the jury to determine.
ESTATE OF BARABIN V. ASTENJOHNSON 13

The district court took the same approach with respect to

expert testimony regarding the “every exposure” theory:

There is obviously a strong divide among both

scientists and courts on whether such expert

testimony is relevant to asbestos-related

cases. In the interest of allowing each party

to try its case to the jury, the Court deems

admissible expert testimony that every

exposure can cause an asbestos-related

disease.

(emphasis added). Just as the district court cannot abdicate

its role as gatekeeper, so too must it avoid delegating that role

to the jury.

Here, the district court delegated that role by giving each

side leeway to present its expert testimony to the jury. Before

allowing the jury to hear the expert testimony, the district

court should have first determined that the “expert meets the

threshold established by Rule 702,” Primiano, 598 F.3d at

564–65; that is the entire purpose of Daubert. The district

court abused its discretion by admitting the expert testimony

without first finding it to be relevant and reliable under

Daubert.

II.

When we conclude evidence has been improperly

admitted, “we consider whether the error was harmless.” 

United States v. Bailey, 696 F.3d 794, 802–03 (9th Cir. 2012). 

We treat the erroneous admission of expert testimony the

same as all other evidentiary errors, by subjecting it to

harmless error review. See United States v. Rahm, 993 F.2d
14 ESTATE OF BARABIN V. ASTENJOHNSON

1405, 1415 (9th Cir. 1993). We reverse “only if the error

affect[ed] a substantial right of the party.” Fed. R. Evid.

103(a). “In other words, we require a finding of prejudice.” 

Obrey v. Johnson, 400 F.3d 691, 699 (9th Cir. 2005).

“[T]he burden [is] on the beneficiary of the error either to

prove that there was no injury or to suffer a reversal of his

erroneously obtained judgment.” Id. at 700 (citation

omitted). Thus, “we begin with a presumption of prejudice. 

That presumption can be rebutted by a showing that it is more

probable than not that the jury would have reached the same

verdict even if the evidence had not been admitted.” Jules

Jordan Video, Inc. v. 144942 Canada Inc., 617 F.3d 1146,

1159 (9th Cir. 2010) (citation and internal quotations

omitted).

As the beneficiaries of the erroneouslyadmitted evidence,

the Barabins fail to rebut the presumption of prejudice. 

Indeed, they admit they cannot win without this expert

testimony.

5 Prejudice is at its apex when the district court

erroneously admits evidence that is critical to the proponent’s

case. The improper admission of the expert testimony

severely prejudiced AstenJohnson and Scapa because the

Barabins’ claim depended wholly upon the erroneously

admitted evidence. Given these circumstances, there is no

doubt the error was not harmless.

5 At least twice during the en banc oral arguments the Barabins admitted

they did not have a case without this expert testimony. First, the Barabins’

counsel stated that, if the district judge found the expert testimony

inadmissible (specifically the testimony of Dr. Millette), the result would

be “a judgment in favor of the defendants.” Second, in response to this

Court’s suggestion that without expert testimony it was “game over” for

the Barabins, counsel stated “I think that’s right.” Our review of the

record confirms the wisdom of this concession.
ESTATE OF BARABIN V. ASTENJOHNSON 15

The dissent contends that we must decide whether the

evidence would be admissible before engaging in harmless

error review. Dissent at 23. However, the dissent is reading

a non-existent step into our evidentiary-error case law.

The dissent cites only two cases addressing the use of

harmless error review in these circumstances.6 They both

support our decision. See 4.85 Acres of Land, 546 F.3d at

620; Simpson v. Thomas, 528 F.3d 685, 691 (9th Cir. 2008). 

In 4.85 Acres of Land, we found that the district court abused

its discretion by excluding all post-taking sales from

consideration without first making any findings regarding the

comparability of the excluded sales to the condemned

property. 546 F.3d at 620. Despite being asked to do so, we

refused to address on appeal whether “some of the posttaking comparable sales would have been admissible.” Id.

Instead, we engaged in harmless error review, found that the

error was not harmless, and remanded for a new trial. Id.

In Simpson, we found that the district court abused its

discretion when it admitted three prior convictions that were

more than ten years old without engaging in proper balancing

6 All of the other cases cited by the dissent do not address this issue. 

They are not cases in which the district court failed to answer a threshold

question of admissibility. Instead, in each of those cases (unlike the case

at hand), we were tasked with determining whether evidence was

admissible in order to decide if the district court abused its discretion. See

Bailey, 696 F.3d at 804–05; Jules Jordan Video, Inc., 617 F.3d at

1157–59; Laurienti, 611 F.3d at 547–49; United States v. Cohen, 510 F.3d

1114, 1127 (9th Cir. 2007); Rahm, 993 F.3d at 1415–16; United States v.

Echavarria-Olarte, 904 F.2d 1391, 1398 (9th Cir. 1990). Here, our

inquiry into whether the district court abused its discretion ends with our

determination that it abdicated its gatekeeping responsibility. However,

to the extent that these cases apply, they support our decision to conduct

harmless error review after finding the district court abused its discretion.
16 ESTATE OF BARABIN V. ASTENJOHNSON

under rule 609(b) of the Federal Rules of Evidence. 528 F.3d

at 690–91. The district court identified the correct rule, but

it abused its discretion when it inverted the requirement of the

rule, failed to offer specific facts to support its conclusion,

and did not find that the probative value substantially

outweighed the prejudice. Id. at 690. We did not engage in

609(b) balancing on appeal to determine whether the prior

convictions would have been admissible. Instead, we went

straight to harmless error review, found the evidence to be

prejudicial, and remanded for a new trial. Id. at 690–91.

As both 4.85 Acres of Land and Simpson illustrate, when

the district court abdicates its responsibility to answer a

threshold question of admissibility, we need not determine

whether the evidence would have been admissible before we

determine the district court abused its discretion and proceed

to harmless error review. In both cases we engaged in

harmless error review, as we always do, by asking if

erroneously admitting or excluding the evidence affected the

outcome of the trial.7See 4.85 Acres of Land, 546 F.3d at

7 The dissent cites Hangarter v. Provident Life & Accident Ins. Co.,

373 F.3d 998 (9th Cir. 2004), to support its idea of what constitutes an

appropriate “harmless error inquiry when a district court fails to fulfill its

gatekeeping function.” Dissent at 26. This case is inapposite; the district

court in Hangarter did not fail to fulfill its gatekeeping function. We

specifically held that the district court “did not abuse its discretion in

finding [the expert’s] testimony reliable based on his knowledge and

experience” and that “the district court’s inquiry was sufficient to comply

with its gatekeeping role.” Id. at 1018.

Instead, in Hangarter, we reviewed for harmless error the district

court’s statement that Daubert did not apply. Id. (“While the district court

erred in stating that Daubert did not apply to Caliri’s non-scientific

testimony, that error was harmless.”). It is difficult to imagine a Daubert

case that is less on point: In Hangarter, the district court said Daubert did
ESTATE OF BARABIN V. ASTENJOHNSON 17

620; Simpson, 528 F.3d at 691. We reject the dissent’s

attempt to insert a new step into our review of evidentiary

errors.

III.

When the district court has erroneously admitted or

excluded prejudicial evidence, we remand for a new trial. 

See, e.g., B.K.B. v. Maui Police Dep’t, 276 F.3d 1091, 1109

(9th Cir. 2002). We do so even if the district court errs by

failing to answer a threshold question of admissibility. See,

e.g., 4.85 Acres of Land, 546 F.3d at 620 (excluding other

sales without determining comparability); Simpson, 528 F.3d

at 691 (admitting convictions without Federal Rule of

Evidence 609(b) balancing). We have no precedent for

treating the erroneous admission of expert testimony any

differently.

For seventy years prior to Daubert, the dominant standard

for determining admissibility of novel scientific evidence was

the “general acceptance” test. Daubert, 509 U.S. at 585–86

(citing Frye v. United States, 293 F. 1013 (D.C. Cir. 1923)). 

Under Frye, we required the proponent of novel scientific

evidence to “lay a proper foundation” by demonstrating

“general acceptance” of the evidence “in the particular field

in which it belong[ed].” United States v. Boise, 916 F.2d 497,

503 (9th Cir. 1990).

In Daubert, the Supreme Court set “the standard for

admitting expert scientific testimony in a federal trial” by

holding that the Federal Rules of Evidence superseded the

not apply but went on to make Daubert findings. Here, the district court

said that Daubert did apply but failed to make Daubert findings.
18 ESTATE OF BARABIN V. ASTENJOHNSON

Frye test. Daubert, 509 U.S. at 582, 586–87. Daubert

continues to require that the proponent of expert testimony

lay a proper foundation, but now laying a proper foundation

means establishing relevancy and reliability rather than mere

general acceptance. Id. at 597.

Initially, in grappling with the effects of Daubert, we

remanded two cases to district courts to conduct post-hoc

Daubert hearings. See United States v. Cordoba, 104 F.3d

225, 229 (9th Cir. 1997); United States v. Amador-Galvan,

9 F.3d 1414, 1418 (9th Cir. 1993).8 After the dust of Daubert

had settled, we held that an erroneous admission of expert

testimony, absent a showing the error was harmless, requires

a new trial. See Mukhtar, 299 F.3d at 1066–67. To the extent

Mukhtar requires anything more, it is overruled.

AstenJohnson and Scapa contend that a reviewing court

should have the authority to make Daubert findings based on

the record established by the district court. We agree and

overrule Mukhtar to the extent that it required that Daubert

findings always be made by the district court. See Mukhtar,

299 F.3d at 1066 n.12. If the reviewing court decides the

record is sufficient to determine whether expert testimony is

relevant and reliable, it may make such findings. If it

“determines that evidence [would be inadmissible] at trial and

that the remaining, properly admitted evidence is insufficient

8 These are not cases in which the district court simply failed to conduct

a Daubert hearing. InAmador-Galvan, the trial took place before Daubert

had been decided, 9 F.3d at 1416, so it would have been impossible for the

district court to make Daubert findings. Cordoba dealt with an issue of

first impression: “whether our per se rule excluding the admission of

unstipulated polygraph evidence was effectively overruled by Daubert.” 

104 F.3d at 227. After deciding it was, we remanded to the district court

to conduct a Daubert hearing in the first instance. Id. at 229.
ESTATE OF BARABIN V. ASTENJOHNSON 19

to constitute a submissible case[,]” the reviewing court may

direct entry of judgment as a matter of law. Weisgram v.

Marley Co., 528 U.S. 440, 446–47 (2000).

Citing Weisgram, AstenJohnson and Scapa argue we

should enter judgment in this case. We decline their

invitation. In Weisgram, the Eighth Circuit found, based on

a fully developed record, that the expert testimony was not

reliable. Weisgram v. Marley Co., 169 F.3d 514, 517–18 (8th

Cir. 1999). We cannot speak to the admissibility of the

expert testimony at issue here because the record before us is

too sparse to determine whether the expert testimony is

relevant and reliable. We can only say with certainty that the

district court erred by failing to make that determination.

The Barabins and the dissent argue that we should remand

for a post-hoc Daubert hearing. Even assuming that a limited

remand is available post-Mukhtar, see 319 F.3d at 1074, it

would not be appropriate under the circumstances here, where

the district court abused its discretion by erroneously

admitting expert testimony, and the evidence was prejudicial. 

We therefore remand for a new trial.

CONCLUSION

The district court failed to make findings of relevancyand

reliabilitybefore admitting into evidence the expert testimony

of Mr. Cohen and Dr. Millette and expert testimony regarding

the theory that “every asbestos fiber is causative.” The

district court’s failure to make these gateway determinations

was an abuse of discretion. The error was prejudicial because

the erroneously admitted evidence was essential to the

Barabins’ case. Due to the district court’s abdication of its

role as gatekeeper and the severe prejudice that resulted from
20 ESTATE OF BARABIN V. ASTENJOHNSON

the error, the appropriate remedy is a new trial. We vacate

the judgment and remand for a new trial.

VACATED and REMANDED.

The parties shall bear their own costs on appeal.

Circuit Judge NGUYEN, with whom Judges McKEOWN,

W.FLETCHER,BYBEE, and WATFORDjoin, concurring

in part and dissenting in part:

I concur in Part I of the majority’s opinion, which

concludes that the district court failed to fulfill its

gatekeeping function with regard to the expert testimony at

issue. I also agree with the majority that we are unable to

determine based on the record before us whether the expert

testimony is admissible. See Maj. Op. at 19 (“We cannot

speak to the admissibility of the expert testimony at issue

here because the record before us is too sparse to determine

whether the expert testimony is relevant and reliable.”). 

Further, to the extent the majority overrules Mukhtar v.

California State University, 299 F.3d 1053 (9th Cir. 2002),

amended by 319 F.3d 1073 (9th Cir. 2003), I am in accord. 

There is no reason to require a new trial whenever a district

court fails to conduct a Daubert analysis, regardless of

whether on remand the district court would determine that

disputed expert testimony is relevant and reliable.

I part ways with the majority, however, in its application

of harmless error review. The majority’s analysis is seriously

flawed because it conflates a district court’s gatekeeping error

with a district court’s erroneous determination of
ESTATE OF BARABIN V. ASTENJOHNSON 21

admissibility. Here, assuminginadmissibility—a question we

cannot answer at this juncture—the majority applies harmless

error review and concludes that a new trial is needed because

the “improper admission of the expert testimony severely

prejudiced [defendants].” Maj. Op. at 14 (emphasis added). 

The majority thus unnecessarily burdens both the parties and

the judicial system by ordering a new trial without having a

sufficient basis to determine whether the disputed expert

testimony was admissible. Further, the majority’s approach

undercuts its effort to open the door to a limited remand

occasioned by overruling Mukhtar. Because I would

conditionally vacate the judgment and remand with

instructions to the district court to conduct a Daubert

determination in the first instance, I respectfully dissent from

Parts II and III of the majority opinion.

I.

A district court must “ensure the reliability and relevancy

of expert testimony” and “make certain that an expert,

whether basing testimony upon professional studies or

personal experience, employs in the courtroom the same level

of intellectual rigor that characterizes the practice of an expert

in the relevant field.” Kumho Tire Co., Ltd. v. Carmichael,

526 U.S. 137, 152 (1999); see also Fed. R. Evid. 702. In

short, a district court serves an essential “gatekeeping”

function in evaluating proffered expert testimony. Kumho

Tire, 526 U.S. at 141.

In this case, the district court abdicated its gatekeeping

role by failing to evaluate the relevancy and reliability of the

expert testimony at issue. Given this oversight, we must

determine whether the district court’s misstep resulted in the

admission of evidence that should have been excluded. In the
22 ESTATE OF BARABIN V. ASTENJOHNSON

past, when the record before us was sufficient to make this

determination, we have proceeded to evaluate whether the

erroneous admission or exclusion of evidence was harmless. 

See, e.g., United States v. Morales, 720 F.3d 1194, 1197 (9th

Cir. 2013) (district court’s error “was harmless because the

erroneously admitted hearsay did not materially affect the

verdict”); United States v. 4.85 Acres of Land, 546 F.3d 613,

620 (9th Cir. 2008) (district court’s error was not harmless

because improper exclusion of evidence was prejudicial). 

This approach makes perfect sense—once we determine that

inadmissible evidence was presented, or that admissible

evidence was excluded, we can then analyze whether the

error materially affected the verdict. See United States v.

Bailey, 696 F.3d 794, 803 (9th Cir. 2012).

Here, however, we face a markedly different scenario. As

the majority correctly concludes, “the admissibility of the

expert testimony at issue” cannot be determined “because the

record before us is too sparse.” Maj. Op. at 19. Given this

conclusion, harmless error review is simply not possible at

the current juncture. Indeed, we cannot even say whether

there was an “error” to “materially affect the verdict.” If the

disputed expert testimony was admissible pursuant to Rule

702 and Daubert, despite the district court’s failure to fulfill

its gatekeeping function, then no harm, no foul. On the other

hand, if the testimony was inadmissible, then a harmless error

analysis would be appropriate. Thus, in light of the

outstanding question regarding the admissibility of the expert

testimony at issue, a remand to the district court for a

Daubert analysis is the proper course.
ESTATE OF BARABIN V. ASTENJOHNSON 23

II.

The majority goes awry in adopting an approach that

ignores this antecedent question of admissibility. In

considering the district court’s gatekeeping failure, the

majority asserts that “[w]hen we conclude evidence has been

improperly admitted, ‘we consider whether the error was

harmless.’” Maj. Op. at 13 (quoting Bailey, 696 F.3d at

802–03). Though innocuous at first glance, this remark

harbors a grave oversight: it equates an incorrect

determination of admissibility with a failure to conduct a

Daubert analysis.

The distinction between the two is crucial. With the

former, we know whether a party was wrongfully permitted

or denied the opportunity to present certain evidence, and we

can determine whether that error was prejudicial. With the

latter, we cannot gauge prejudice unless we are able to

determine what the jury would have been permitted to hear

had the district court properly discharged its gatekeeping

duties.1

By skipping over the question of admissibility and

heading straight for prejudice, the majority’s analysis results

in two key missteps. First, the majority dubs the Barabins

“the beneficiaries of . . . erroneously admitted evidence.” Id.

1 The majority cites United States v. Rahm, 993 F.2d 1405 (9th Cir.

1993), for the proposition that “[w]e treat the erroneous admission of

expert testimony the same as all other evidentiary errors, by subjecting it

to harmless error review.” Maj. Op. at 13. Rahm, however, only engaged

in harmless error review after concluding that the testimony at issue was

admissible and thus improperly excluded. See Rahm, 993 F.2d at 1416

(deeming the error not harmless where the district court “erroneously

excluded . . . proffered expert testimony . . . [that] was admissible”).
24 ESTATE OF BARABIN V. ASTENJOHNSON

at 14. But, as the majority acknowledges, we have no idea

whether the expert testimony at issue was in fact “erroneously

admitted.” On a proper Daubert analysis—a task we decline

to engage in on appeal—the testimony might indeed have

been admissible. In this circumstance, the Barabins would

merely be the beneficiaries of evidence they were entitled to

present in the first place.

Second, in bypassing admissibility, the majority engages

in a perplexing prejudice analysis that emphasizes the fact

that the disputed expert testimony was “critical to the

proponent’s case.”2Id. Indeed, based on its conclusion that

“the Barabins’ claim depended wholly upon the erroneously

admitted evidence,” the majority finds “no doubt the error

was not harmless.” Id. Not so. Even if the Barabins’ claim

depended on the expert testimony at issue, we have no idea

whether the testimony was “erroneously admitted,” let alone

whether any error “materially affect[ed] the verdict.” 

Morales, 720 F.3d at 1197. If the expert testimony was

admissible, then the jury simply reached a verdict based on

evidence it was properly permitted to consider, despite the

district court’s error.

The flaw in the majority’s logic is highlighted by the fact

that not a single case it cites supports the type of harmless

error analysis it applies. Rather, in each case, we engaged in

harmless error review only after we determined that evidence

2

It seems to me that it would be the rare case indeed where expert

testimony was not “critical to the proponent’s case.”
ESTATE OF BARABIN V. ASTENJOHNSON 25

had been improperly deemed admissible or inadmissible.3

Indeed, this is true of Simpson v. Thomas and United States

v. 4.85 Acres of Land—two cases specifically discussed by

the majority in support of its decision. Contrary to the

majority’s assertion, neither case involved merely a situation

where a “district court abdicate[d] its responsibility to answer

a threshold question of admissibility.” Maj. Op. at 16. 

Rather, in both cases, we found actual error by the district

court in deeming evidence admissible or inadmissible before

proceeding to harmless error review. See Simpson, 528 F.3d

at 689 (“The district court erred in admitting the evidence of

Simpson’s three prior felony convictions.”); 4.85 Acres of

Land, 546 F.3d at 620 (“[T]he [district] court simply

excluded all post-taking sales based on ‘the erroneous

premise . . . that evidence of subsequent sales is never proper

for consideration in arriving at fair market value.’” (quoting

3

See, e.g., Bailey, 696 F.3d at 805 (not harmless error where trial court

wrongfullyadmitted a civil complaint); Jules JordanVideo, Inc. v. 144942

Canada, Inc., 617 F.3d 1146, 1158–59 (9th Cir. 2010) (harmless error

where district court improperly permitted counsel to read 716 requests for

admissions to the jury); United States v. Laurienti, 611 F.3d 530, 548 (9th

Cir. 2010) (harmless error where district court abused its discretion by

sustaining certain government objections to expert testimony); Simpson

v. Thomas, 528 F.3d 685, 691 (9th Cir. 2008) (not harmless error where

district court improperly admitted prior convictions); 4.85 Acres of Land,

546 F.3d at 620 (not harmless error where district court improperly

excluded post-taking sales in a condemnation action); Cohen, 510 F.3d at

1127 (not harmless error where district court wrongfully excluded expert

testimony); Obrey v. Johnson, 400 F.3d 691, 702 (9th Cir. 2005) (not

harmless error where district court abused its discretion in excluding

testimony); Rahm, 993 F.2d at 1415 (not harmless error where district

court erroneously excluded expert testimony); United States v.

Echavarria-Olarte, 904 F.2d 1391, 1398–99 (9th Cir. 1990) (harmless

error where district court improperly admitted expert testimony on drug

cartel).
26 ESTATE OF BARABIN V. ASTENJOHNSON

United States v. 1,129.75 Acres of Land, 473 F.2d 996, 999

(8th Cir. 1973)) (final alteration in original)).

In fact, our case law suggests a notably different harmless

error inquiry when a district court fails to fulfill its

gatekeeping function. For example, in Hangarter v.

Provident Life & Accident Insurance Co., 373 F.3d 998 (9th

Cir. 2004), the district court incorrectly concluded that

Daubert was inapplicable to the non-scientific testimony of

an independent consultant. Id. at 1015–16, 1018. We found

the error harmless because “the [district] court’s probing of

[the consultant’s] knowledge and experience was sufficient

to satisfy its gatekeeping role under Daubert.” Id. at 1018. 

In short, the district court’s failure to analyze the expert

testimony pursuant to Daubert was harmless because the

analysis it nonetheless conducted satisfied Daubert and the

testimony was thus correctly admitted. This was a proper

application of harmless error review—where the error

identified on appeal pertains to the gatekeeping function, the

reviewing court should consider whether the gatekeeping

error was harmless.4

In contrast, the majority here finds a gatekeeping error,

but embarks on a prejudice inquiry that focuses on how

crucial the disputed expert testimony was to the prevailing

party’s success. In doing so, the majority effectively treats

the testimony as inadmissible, even as it professes to reserve

4 The majority characterizes Hangarter as “inapposite,” describing it as

a case where the district court “did not fail to fulfill its gatekeeping

function.” Maj. Op. at 16 n.7. I disagree. It is hard to imagine a more

clear gatekeeping error than a district court choosing not to analyze

proffered expert testimony under Daubert because it mistakenly found

Daubert inapplicable.
ESTATE OF BARABIN V. ASTENJOHNSON 27

judgment on the question. The majority cannot have it both

ways.

III.

I would conditionally vacate the judgment and remand to

the district court with instructions to determine whether the

disputed expert testimony was admissible pursuant to the

requirements of Rule 702 and Daubert. If the testimony is

determined to be admissible, the district court may reinstate

the verdict. If, however, the testimony is inadmissible, the

district court should ascertain whether the wrongful

admission of that expert testimony prejudiced the defendants

and, if so, order a new trial. In the former case, the system

will not be unreasonably burdened with a retrial. In either

case, the parties retain their right to appeal. This solution

makes practical and legal sense.