The Changing Face of Expert Evidence
Mitchell
L. Lathrop
I.
Introduction
Virtually all cases
involving scientific or technical issues, or even professional standards,
require expert witnesses and expert testimony.
The rules that have evolved and the standards that are required
regarding expert testimony are by no means uniform, as they vary depending upon
the jurisdiction. Juries are frequently
asked to decide between the conflicting testimony of two or more expert
witnesses, with little or no guidance from the court. As Judge Learned Hand pointed out more than a century ago, “how
can the jury judge between two statements each founded upon an experience
confessedly foreign in kind to their own?
It is just because [jurors] are incompetent for such a task that the
expert is necessary at all.”[1] The last half of the twentieth century saw
an ever-growing debate about the standards that should be applied to expert
testimony and the safeguards that should be applied to prevent abuse.[2]
At the outset, it must be
remembered that there are three general areas of expert evidence: (1) pure
opinion expert evidence, (2) scientific expert evidence, and (3) non-scientific
expert evidence. The rules that govern
the admission of each may vary, both in terms of the standards for admission in
the first instance as well as the standard for reviewing decisions of the trial
court. Different jurisdictions have
formulated different tests for the admission of all types of expert evidence,
and care must be taken to identify precisely what rules apply to each
jurisdiction.
All too often courts avoid
the issue of admissibility by stating, “it goes to the weight, not the
admissibility,” and then simply let everything in. The recent trend, however, has been toward a more careful scrutiny
of expert evidence by trial courts. As
the Fifth Circuit Court of Appeals so aptly put it in In re Air Crash Disaster at New Orleans, Louisiana:[3]
Basic
policy questions that affect the very nature of a trial lie behind decisions to
receive expert testimony. Under the
Federal Rules of Evidence, experts not only explain evidence, but are
themselves sources of evidence.
. .
. .
. .
. [W]e recognize the temptation [on the part of the trial judge] to answer
objections to receipt of expert testimony with the shorthand remark that the
jury will give it “the weight it deserves.” . . . Trial judges must be sensitive to the qualifications of persons
claiming to be expert. . . .
In
sum, we adhere to the deferential standard for review of decisions regarding the
admission of testimony by experts.
Nevertheless, we take this occasion to caution that the standard leaves
appellate judges with a considerable task.
We will turn to that task with a sharp eye, particularly in those
instances, hopefully few, where the record makes it evident that the decision
to receive expert testimony was simply tossed off to the jury under a “let it
all in” philosophy. Our message to our
able trial colleagues: it is time to take hold of expert testimony in federal
trials.[4]
The same admonition is equally applicable to state
courts.
II.
The Frye
Rule
Modern rules governing
expert testimony in federal courts and many states have their origin in the
seminal case of Frye v. United States.[5] It has been refined and to some extent
replaced by what has become known as “the expert evidence trilogy.” The three landmark cases decided by the
Supreme Court that make up the trilogy are: Daubert
v. Merrell Dow Pharmaceuticals, Inc.;[6] General Electric Co. v. Joiner;[7]
and Kumho Tire Co., Ltd. v. Carmichael.[8]
Decided in 1923 by the
District of Columbia Court of Appeals, Frye
established the “general acceptance test.”
As the court held “while courts will go a long way in admitting expert
testimony deduced from a well-recognized scientific principle or discovery, the
thing from which the deduction is made must be sufficiently established to have
gained general acceptance in the particular field in which it belongs.”[9] From its genesis in 1923 through at least
the 1960s, the rule of Frye achieved
general acceptance in both federal and state courts. In 1954, however, Professor Charles McCormick published his
treatise on evidence in which he opined that the general acceptance test “is a
proper condition upon the court’s taking judicial notice of scientific facts,
but not a criterion for the admissibility of scientific evidence.”[10] McCormick argued that, “[a]ny relevant
conclusions which are supported by a qualified expert witness should be
received unless there are other reasons for exclusion. Particularly, its probative value may be
overborne by the familiar dangers of prejudicing or misleading the jury, unfair
surprise and undue consumption of time.”[11] In McCormick’s view, any expert testimony
should be admitted if the expert witness has sufficient credentials as an
expert and no independent reasons exist to exclude the testimony. He thought it is the role of the jury to
determine the credibility of the expert witness and decide what weight the
testimony should be given.
A significant weakness of
the Frye rule is that it does not
address situations involving new, unique or novel scientific evidence. Unless the scientific principle that the
expert’s testimony is based upon is sufficiently established in the scientific
community, the expert testimony must be rejected under Frye.
Also, a question left
largely unanswered by the Frye rule
is exactly what the scientific community must generally accept. Should it be the conclusion of the expert
witness, the methodology used to arrive at the conclusion or the mode of
reasoning and applying the scientific principles involved? What should be the effect of applying a
generally accepted scientific principle in an unaccepted way? Should the Frye rule be applied to disciplines other than those considered
strictly scientific, such as economics, social sciences, and epidemiology? Even if an expert’s methodology is generally
accepted, how is that methodology being used in the particular case? It was not until the 1990s that many of
these questions were considered by the courts, and the then-existing Federal
Rules of Evidence offered little help.
Nevertheless, the Frye rule is still followed by at least
seventeen states.[12]
III.
The Federal Rules of Evidence
The Federal Rules of
Evidence became effective in 1975. Like
Frye before them, the Rules contained
no standard for the admission of new or novel scientific evidence, regardless
of the credentials of the expert witness seeking to give such expert
testimony. Expert testimony is governed
by Rule 702, as amended in 2000, which states that “[i]f 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.”[13] However, conspicuously absent from the Rules
and the Advisory Committee comments is any consideration of the Frye “general acceptance test.”
Rule 702 gives wide
discretion to trial courts to accept or reject expert testimony. Further, Rule 703 allows an expert witness
to be “fed” facts or data in a particular case either during trial or
before. Such facts or data could form
the basis for the expert’s opinion “[i]f of a type reasonably relied upon by
experts in the particular field in forming opinions or inferences upon the
subject . . .”[14] Moreover, the facts or data “need not be
admissible in evidence.”[15] The facts or data, however, may be elicited
on cross-examination if not otherwise brought out.[16]
The wide judicial discretion
and lack of strict standards resulted in a proliferation of “junk science,”
although there was also some judicial acceptance of legitimate new scientific
testimony. Courts tended to admit
everything, retreating to the well-worn response that “it goes to the weight,
not the admissibility.” Faced with the
broad, non-specific language of the Rules, federal courts continued to apply
the Frye rule, sometimes without even
mentioning it. For example, in Sterling v. Velsicol Chemical Corp.,[17] the court
excluded testimony about “clinical ecology” because it was not generally
accepted in the relevant scientific community.
The Velsicol case was a class action brought against Velsicol Chemical
Corporation because of its use of rural land in Hardeman County, Tennessee to
dispose of by-products from the production of chlorinated hydrocarbon
pesticides. Velsicol conducted no
hydrogeological studies to determine soil composition, the water flow
direction, or the location of the local water aquifer. The result was the potential contamination
of local drinking water wells.
Additional tests performed after the initial studies confirmed the
contamination of the local drinking water aquifer. Forty-two plaintiffs sued Velsicol. Over its objections, the district court certified a class and
proceeded to hold a bench trial.
At trial, both the
plaintiffs and Velsicol utilized the Trescott, Pinder and Larson computer model
to trace the level of chemical contamination.
However, there were dramatic differences between presentations due to
the use of different assumptions concerning the contaminant loading rates and
porosity.[18] The district court rejected Velsicol’s model
as inaccurately under-representing the extent of chemical contamination in the
ground water supply.
The plaintiffs also
introduced evidence of immune system impairment based upon harm caused by
Velsicol’s chemicals. Their testifying
experts stated that, on the basis of clinical ecological tests, Velsicol's
chemicals damaged the plaintiffs' immune systems. Clinical ecology is premised on a belief that exposure to a
number of factors including, but not limited to, anxiety, radiation, certain
chemicals, and some common household substances can cause immune system
impairments.
The district court found
Velsicol liable to the plaintiffs on legal theories of strict liability, common
law negligence, trespass, and nuisance.
It awarded compensatory damages of over $5 million, prejudgment
interest, and $7.5 million in punitive damages to the class as a whole. Velsicol appealed the decision, challenging
the validity of groundwater modeling techniques in general, as well as the
particular model used by the plaintiffs in that it fatally failed to utilize
all relevant data. Velsicol also
challenged the general concept of clinical ecology.
The Sixth Circuit Court of
Appeals reversed the district court.
Although it upheld the use of computer modeling to determine the rate of
contaminants in soil, it rejected the concept of clinical ecology. The court held that Rule 702 mandates that a
four-part test be met to uphold the admission of expert testimony. The test requires “(1) a qualified expert
(2) testifying on a proper subject (3) which is in conformity to a generally
accepted explanatory theory (4) the probative value of which outweighs its
prejudicial effect.”[19] The court held that the third criterion had
not been met. Clinical ecology was not
sufficiently established to have gained wide acceptance in the field to which
it belongs. The court noted that,
“[t]he leading professional societies in the specialty of allergy and
immunology, the American Academy of Allergy and Immunology (AAAI) and the
California Medical Association (CMA), have rejected clinical ecology as an
unproven methodology lacking any scientific basis in either fact or theory.”[20] The court clearly relied on Frye in reaching its decision, yet it
made no mention of that case in its opinion.
Nevertheless, “junk science”
continues to be used. The case of DeLuca v. Merrell Dow Pharmaceuticals, Inc.[21]
involved birth defects allegedly caused by the mother’s ingestion during
pregnancy of Bendectin, a drug manufactured and distributed by Merrell
Dow. Merrell Dow filed a motion for
summary judgment. It claimed that the
only causation evidence produced by the plaintiff was inadmissible because all
relevant epidemiological studies at the time determined there was no
statistically significant link between the use of Bendectin during pregnancy
and the type of birth defects suffered by the child. The plaintiff submitted affidavits and deposition testimony by an
expert in pediatric pharmacology. That
expert opined that the available epidemiological data did, in fact, support the
conclusion that Bendectin causes limb reduction defects and that he believed,
to a reasonable degree of medical certainty, that Bendectin caused the child’s
defects.[22] The district court held that such testimony
would be inadmissible at trial because it was not based on data of a type
reasonably relied upon by experts in the pertinent fields in issuing opinions
on those subjects. Since the expert’s
testimony was the sole causation evidence tendered in response to Merrell Dow’s
motion, the district court entered summary judgment for Merrell Dow.
On appeal, the plaintiff
argued that the district court misapplied Rule 703. The Court of Appeals reversed under the guise of a strict
reliability test, but in actuality it endorsed expert testimony that was
unlikely to meet either the requirements of Rule 703 or Frye. While there was no
question at the time that Bendectin was the target of hundreds of lawsuits
claiming birth defects resulting from its use during pregnancy, the scientific
evidence was still inconclusive as to its teratogenicity. The court held that “an expert’s opinion
need not be generally accepted before it can be sufficiently reliable and
probative to be submitted to the jury and perhaps support a jury finding.”[23] On remand, the district court found that the
expert witness:
has presented no evidence
that his methodology has been put to any non-judicial use. Although “the Federal Rules of Evidence
contain no requirement that an expert’s testimony be based upon reasoning
subjected to peer-review and published in the professional literature,” the
fact that [the expert’s] methodology has not been used non-judicially weighs
against its admissibility.[24]
The district court concluded that the expert’s
testimony was inadmissible under Rules 702 and 703, and again entered summary
judgment in favor of Merrell Dow.
The economic impact of “junk
science” decisions has been considerable.
Products have been forced off the market because of questionable expert
testimony.[25] Some manufacturers stopped producing
products because they could be the target of the “almost unlimited pool of
[plaintiffs’] experts. . . . While
attorneys are stuck with the testimonial limitations of the available fact
witnesses, an attorney who needs an expert can ‘shop’ for an expert with a
pleasing courtroom manner who will agree with the attorney’s theory of the
case.”[26]
Having signaled in 1989 that
it would support the application of Frye
to toxic torts,[27]
in 1991 the Fifth Circuit Court of Appeals applied Frye in the case of Christophersen
v. Allied-Signal Corp.[28] That case involved a wrongful death claim
from exposure to heavy metal fumes. The
decedent died of a rare, small-cell form of cancer that was allegedly caused by
exposure to fumes at his place of employment.
The district court entered summary judgment in favor of the defendant,
finding that the facts and data relied upon by the plaintiffs’ expert witness
were insufficient to meet the standards of Rule 703. The appellate court, in a 9-3 decision, affirmed the district
court. It determined that a
four-pronged test is required before expert testimony can be admitted:
(1) Whether the witness is
qualified to express an expert opinion, Fed.R.Evid. 702;
(2) whether the facts upon
which the expert relies are the same type as are relied upon by other experts
in the field, Fed.R.Evid. 703;
(3) whether in reaching his
conclusion the expert used a well-founded methodology, Frye; and
(4) assuming the expert's
testimony has passed Rules 702 and 703, and the Frye test, whether under Fed.R.Evid. 403 the testimony’s potential
for unfair prejudice substantially outweighs its probative value.[29]
The court seemingly foresaw the expert evidence
trilogy that was to emerge from the Supreme Court over the next eight years.
At about the same time,
Peter Huber’s book Galileo’s Revenge:
Junk Science in the Courtroom was published. The work attracted great attention throughout the judiciary and
the trial bar, and clearly influenced the Ninth Circuit Court of Appeals when
it decided Daubert v. Merrell Dow
Pharmaceuticals, Inc.[30] Daubert,
like DeLuca, involved birth defects
attributed to Bendectin taken by a mother during pregnancy. In Daubert
two boys were born with defects that reduced the size of their limbs. The parents sued Merrell Dow
Pharmaceuticals. During the ensuing
litigation, Merrell Dow introduced extensive epidemiological studies showing that
exposure to Bendectin in utero did
not result in a higher rate of limb reductions than the rate for babies who
were not exposed. On rebuttal, the
plaintiff’s experts gave opinions based on in
vitro and in vivo animal tests,
chemical structure analyses and the reanalysis of previously conducted
epidemiological studies. On that basis
they opined that Bendectin was a teratogen.
The district court refused to admit the evidence proffered by
plaintiff’s experts and entered summary judgment for Merrell Dow, finding that
the re-analyses had neither been published nor subjected to peer review.
The Ninth Circuit affirmed,
noting that:
Scientific studies conducted
in anticipation of litigation must be scrutinized much more carefully than
studies conducted in the normal course of scientific inquiry. This added dose of skepticism is warranted,
in part, because studies generated especially for use in litigation are less
likely to have been exposed to the normal peer review process, which is one of
the hallmarks of reliable scientific investigation.[31]
The court observed that Frye governed the admissibility of
scientific evidence in the Ninth Circuit, despite the fact that the Frye rule had not previously been
applied in a civil case in the Ninth Circuit, and had only been applied twice
before in the toxic tort context in other jurisdictions.[32]
Daubert’s use of the Frye rule as
the basis for the exclusion of expert testimony in a toxic tort case gained
widespread notoriety, at least while the decision was in effect. However, the Supreme Court granted
certiorari in Daubert to decide
whether Frye was still viable
precedent under the Federal Rules of Evidence.
Thus began what would become the federal expert evidence trilogy.
IV.
The Federal Expert Evidence Trilogy
The Supreme Court reversed
the Ninth Circuit’s decision in Daubert
v. Merrell Dow Pharmaceuticals, Inc.[33] In a unanimous decision as to the principal
holding, Justice Blackmun authored the Court’s opinion.[34] The Court held that the Frye “general acceptance” test was superceded by the adoption of
the Federal Rules of Evidence, but that Rule 702 nonetheless gives trial judges
a “gatekeeping” responsibility in deciding questions of the admissibility of
proffered expert testimony. General
acceptance was held to no longer be a necessary precondition to the
admissibility of scientific evidence under the Federal Rules of Evidence, since
nothing in the text of Rule 702 establishes general acceptance as an absolute
prerequisite to admissibility. Neither
the Rule itself nor the Advisory Committee comments indicate that Rule 702 or
the Federal Rules of Evidence as a whole were intended to incorporate the Frye general acceptance standard. Nevertheless, the Court held, the Federal
Rules of Evidence require that a federal trial judge must ensure that any and
all scientific testimony or evidence is not only relevant but reliable. The majority went on to hold that in a
federal case involving scientific evidence, evidentiary reliability must be
based on scientific validity.
It was this latter point
that caused Chief Justice Rehnquist and Justice Stevens to dissent in
part. Obviously concerned about the
ability of federal judges to become instant scientists capable of determining
the validity of proffered scientific evidence, Chief Justice Rehnquist
observed, “I do not doubt that Rule 702 confides to the judge some gatekeeping
responsibility in deciding questions of the admissibility of proffered expert
testimony. But I do not think it imposes
on them either the obligation or the authority to become amateur scientists in
order to perform that role.”[35]
Although the Ninth Circuit’s
decision was reversed, the Daubert
standard that replaced Frye achieves
much the same end result. Federal
courts must strictly scrutinize scientific expert testimony for both
evidentiary reliability and scientific validity. In some cases that may even require the court to appoint its own
experts under Rule 706(a). Arising as
it did from a birth defect case, Daubert
dealt with scientific evidence focused on alleged harm flowing from the
ingestion of an allegedly defective product.
It did not decide what standard of review should be applied in cases
where the trial court excludes expert testimony. It was not until four years later that a case involving exposure
to allegedly carcinogenic substances reached the high court.
In General Electric Co. v. Joiner,[36] an
electrician, Joiner, contracted lung cancer allegedly promoted by exposure to
polychlorinated biphenyls (PCBs) contained in electrical transformers and
dielectric fluid.[37] The electrician sued the manufacturers of
the transformers and the dielectric fluid on theories of strict liability,
negligence, fraud, and battery. The
district court, on the manufacturers’ motion for summary judgment, excluded the
testimony of the electrician’s experts and granted the manufacturers’
motion. The court found that Joiner
failed to show by a preponderance of the evidence that the expert opinions
regarding a connection between PCB and lung cancer were admissible under the
standards set out by Rule 702 and Daubert.
Joiner appealed to the
Eleventh Circuit Court of Appeals. In a
2 to 1 decision it reversed and remanded, applying a de novo standard of review to the admissibility of expert opinions.[38] The majority decided that the trial court
improperly assessed the admissibility of the expert testimony and overlooked
evidence establishing disputed issues of fact.
It found that Joiner had sufficiently demonstrated the basis of the expert’s
testimony and their scientific reliability. Ruling that the Federal Rules of
Evidence liberalized the Frye
standard, the majority misinterpreted the holding in Daubert. As the dissent
noted:
As a “gatekeeper,” the trial
court must sift through expert testimony to decide not only whether an expert
may testify, but what portion of the expert’s testimony is admissible. A single expert may offer several opinions
to reach his ultimate conclusion, and each opinion must be admissible under Daubert. Further, an expert’s testimony
does not “assist” the trier of fact if the expert does not explain the steps he
took to reach his conclusion. We should
not require the trier of fact to accept blindly the expert’s word to fill the
analytical gap between proffered “scientific knowledge” and the expert’s
conclusions. Therefore, the trial court
“gatekeeper” has broad discretion to decide whether a leap of faith across the
analytical gap is so great that, without further credible grounds, the
testimony is inadmissible.[39]
The Supreme Court granted
certiorari and reversed the Eleventh Circuit.
The Court, in an opinion authored by Chief Justice Rehnquist, held that
an “abuse of discretion” standard applies to a review of a trial court’s
decision to exclude scientific evidence.[40] It found that in the instant case, the
district court did not abuse its discretion in excluding expert testimony based
on studies indicating that infant mice developed cancer after receiving massive
doses of PCBs, nor did the district court abuse its discretion in excluding
expert testimony based on epidemiological studies. The high court pointed out that “while the Federal Rules of
Evidence allow district courts to admit a somewhat broader range of scientific
testimony than would have been admissible under Frye, they leave in place the gatekeeper role of the trial judge in
screening such evidence.”[41] The second leg of the expert evidence
trilogy was now in place, but a decision on the applicability of the Rule 702/Daubert/Joiner standards to the testimony of engineers and other experts
who are not scientists in a traditional sense was yet to come.
On July 6, 1993, the right
rear tire of a minivan driven by Patrick Carmichael blew out. In the accident that followed, one of the
passengers died, and others were severely injured. The Carmichaels sued the tire’s manufacturer and its distributor,
collectively “Kumho Tire.”[42] The claim was that the tire was
defective. On cross-motions for summary
judgment, the Carmichaels relied in large part on deposition testimony given by
an expert in tire failure analysis.
Much of the testimony given by Carmichael’s expert was not in dispute,
including the method of manufacture of steel-belted radial tires. However, the expert made certain assumptions
that the parties could not agree upon, among them the fact that the tire had
traveled a great number of miles. The
tire was manufactured in 1988. The
Carmichaels had purchased the used minivan in 1993 when the odometer showed
88,997 miles, and had driven it approximately 7,000 miles before the accident. The tire tread depth showed considerable
wear, and the tire had suffered at least two punctures that had been
inadequately repaired.
The challenges to the
Carmichael’s expert witness were significant.
The expert whose deposition testimony was used in opposition to Kuhmo
Tire’s motion for summary judgment was the second expert hired by the
Carmichaels, replacing a previous expert.
The original expert had examined and taken photographs of the tire. The second expert reviewed those
photographs, and adopted the first expert’s report and conclusions as his
own. The second expert examined the
tire for the first time on the morning that his deposition was taken, after the
original expert had issued his written report and conclusions regarding the
cause of the blowout. The second expert
performed no tests on any of the minivan’s tires at that time, and his analysis
was limited to a visual inspection of the tire, though he conceded that cutting
the tire and physically examining it could reveal additional pertinent
information.
Kumho Tire moved the
district court to exclude the expert’s testimony on the ground that his
methodology failed Rule 702’s reliability requirement. The court agreed with Kumho Tire that it
should act as a Daubert-type
reliability “gatekeeper,” even though the expert’s testimony was “technical,”
rather than “scientific.”[43] Having examined the expert’s methodology and
the reliability-related factors mandated by Daubert,
the court granted the motion to exclude the testimony and entered summary
judgment in favor of Kuhmo Tire.[44]
On appeal, the Eleventh
Circuit Court of Appeals reversed and remanded. The appellate court held that “[t]he district court erred as a
matter of law in applying the Daubert criteria to the Carmichaels’ proffered expert
testimony.”[45] Its reasoning was that because the testimony
of the expert was based on observation and experience rather than upon
scientific theory, the Daubert
standard did not apply.
The Supreme Court granted
certiorari and reversed. It noted that
Rule 702 states that “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.”[46] The high court noted that the language of
Rule 702 makes no relevant distinction between scientific knowledge and
technical or other specialized knowledge.
Rather, the rule is clear that any type of knowledge could become the
subject of expert testimony. The word
“knowledge” is the governing word that “establishes the standard of evidentiary
reliability.”[47] As a result, the reliability standard
applies to all scientific, technical, or other specialized matters.
The Supreme Court was clear
in Kuhmo Tire that Daubert’s principles apply to all expert
matters described in Rule 702 and serve to clarify and define the standard of
evidentiary reliability. It is the
trial judge who must determine whether proffered expert testimony has a
reliable basis in the knowledge and experience of the relevant discipline, as
well as a valid connection to the subject matter of the issues as a
precondition to admissibility. Factors
which may be properly considered by a trial judge in fulfilling the gatekeeper
obligation to determine the admissibility of an expert’s testimony include
“whether a theory or technique . . . can be (and has been) tested,” whether it
“has been subjected to peer review and publication,” whether, “in respect to a
particular technique, there is a high ‘known or potential rate of error’ and
whether there are ‘standards controlling the technique’s operation,’” and
whether the “theory or technique enjoys ‘general acceptance’ within a ‘relevant
scientific community.’”[48] With the Court’s decision in Kuhmo Tire the expert evidence trilogy
was now complete.
V.
Pure opinion expert evidence
“Pure opinion” expert
evidence is expert evidence developed from inductive reasoning based on the
expert’s own experience, observation, or research. Pure opinion expert testimony is commonly found in professional
liability cases. In that setting
experts are testifying about the standard of care or the standard of conduct,
not about scientific or technical processes or theories. A discussion of pure opinion expert evidence
is found in Kuhn v. Sandoz
Pharmaceuticals Corp.[49] In Kuhn
the plaintiffs’ mother died following childbirth. She had been given a single dose of Parlodel, a drug manufactured
by Sandoz Pharmaceuticals (Sandoz) designed to prevent postpartum lactation in
mothers who did not intend to breast feed their babies. Her survivors sued Sandoz claiming the
Parlodel caused or contributed to her death.
The plaintiffs produced several expert witnesses who pointed to Parlodel
as a cause or contributing factor to the death. On cross-examination, Sandoz brought out that plaintiffs’
experts: (1) were “unable to identify any human study to support their
hypotheses,” (2) admitted that “no epidemiological evidence concludes that
Parlodel causes cerebral edema,” (3) are “not aware of any study demonstrating
a statistically significant rise in blood pressure associated with the use of
Parlodel,” (4) admitted that “there is no epidemiological evidence that a
single dose of Parlodel can cause seizure, hypertension, or death,” (5)
admitted “there is no statistically significant epidemiology demonstrating an
increased incidence of stroke, seizure, myocardial infarction, or hypertension
with Parlodel use,” and (6) were “not aware of any epidemiological studies
associating Parlodel with any cardiac events.”[50] The plaintiffs established that Sandoz had
been requested by the F.D.A. to remove the recommendation that Parlodel be used
for lactation suppression because the possibility that the product might cause
serious adverse experiences in some patients outweighed the limited benefits
associated with its use. After Sandoz
refused to voluntarily remove the indicated use, the F.D.A. initiated
procedures for withdrawing approval for the indication. A day later, Sandoz withdrew the Parlodel
indication for the prevention of lactation in the United States.
The district court ruled
that plaintiffs’ expert witnesses improperly offered medical causation opinions
concerning Parlodel without general acceptance of the bases for those opinions
within the relevant scientific community.
It dismissed the plaintiffs’ case with prejudice and the plaintiffs
appealed. The Kansas Supreme Court
recognized that traditionally it has applied an abuse of discretion standard to
the review of evidentiary decisions by trial courts. It further noted that the Frye
rule should be used when an expert witness reaches a conclusion by deduction
from applying a new or novel scientific principal, formula, or procedure
developed by others. The court held
that the Frye rule was inapplicable
to pure opinion expert testimony.
Rather, the Frye rule applies
only “when an expert witness reaches a conclusion by deduction from applying a
new or novel scientific principal, formula, or procedure developed by others.”[51] The court went on to state that “validity of
pure opinion is tested by cross-examination of the witness. The validity of an opinion subject to Frye is tested by inquiring into general
acceptance as reliable within the expert’s particular scientific field.”[52]
Courts have taken differing
views on whether pure opinion (i.e., personal observation) testimony should be
subject to scrutiny under Frye or
otherwise prior to its admission. For
example, in Case of Canavan,[53]
the plaintiff claimed an inability to work because of exposure to
chemicals. The case involved the
Massachusetts Industrial Accident Reviewing Board (IARB), which upheld a
finding that the plaintiff, a nurse, was temporarily unable to work and that
her medical treatment was reasonable and necessary. She claimed that her duties in the operating room exposed her to
multiple chemicals including ethylene oxide, formaldehyde, and diesel fuel. She experienced headaches, dizziness, nasal
congestion, swelling of her nose and right cheek. Ultimately, a physician highly qualified in pediatrics and
certified in environmental medicine treated her. The American Board of Environmental Medicine certified the
physician. However, environmental medicine was not a field recognized by the
American Board of Medical Specialties.
The physician determined that the nurse suffered from “arthritis,
paresthesias, organic brain syndrome, chemical induced headaches,
immunodeficiency, and multiple chemical sensitivities (MCS) secondary to
chemical poisoning, which [he] believed was caused by exposure during her
employment at the hospital.”[54] He testified as an expert that MCS “is a
systemic reaction of the body with multiple symptoms to multiple kinds of
chemicals, which may be chemically unrelated, which are commonly present in the
everyday working and living environment where that environment has not been
meticulously cleaned up and had the chemical sources removed.”[55] The expert stated that tests that he
conducted showed that the plaintiff suffered from MCS and that her injury was
caused at her work by chemical poisoning. The expert for the defendant hospital
was a board certified expert in allergy and immunology. He testified that chemicals at her work did
not cause the plaintiff’s condition and that MCS is “not accepted as a
diagnostic disease by mainstream allergists/immunologists and occupational
medicine physicians.”[56] The hospital’s expert diagnosed the
plaintiff as suffering from chronic nonallergic rhinitis, a disease caused by
nonspecific stimuli existing in the everyday environment.
The Appeals Court affirmed
the IARB decision and the Supreme Judicial Court of Massachusetts (SJC) granted
further appellate review and reversed.
The hospital argued that the plaintiff’s expert medical testimony was
not based on a reliable methodology in accordance with the standards set forth
in Commonwealth v. Lanigan,[57]
and should not have been admitted by the trial judge. The SJC adopted the abuse of discretion standard set forth in Joiner and Kumho Tire. It noted “that
applying an abuse of discretion standard on appellate review will allow trial
judges the needed discretion to conduct the inherently fact-intensive and
flexible Lanigan analysis, while
preserving a sufficient degree of appellate review to assure that Lanigan determinations are consistent
with the law and supported by a sufficient factual basis in the particular
case.”[58] The SJC went on to observe that since its
decision in Vassallo v. Baxter Healthcare
Corp.,[59]
wherein it explicitly reserved the question whether expert testimony based on
clinical experience and personal observations would be admissible without Lanigan analysis, the Supreme Court had
decided Kumho Tire. There the Court held that the expert’s
observations were subject to a Daubert
analysis. The question before the trial
judge is whether the expert’s specific observations are sufficiently reliable
to support the expert’s ultimate conclusion.
The SJC agreed and adopted Kumho
Tire, requiring a Lanigan
analysis:
“That a person qualifies as
an expert does not endow his testimony with magic qualities.” Observation
informed by experience is but one scientific technique that is no less
susceptible to Lanigan analysis than
other types of scientific methodology.
The gatekeeping function pursuant to Lanigan
is the same regardless of the nature of the methodology used: to determine
whether “the process or theory underlying a scientific expert’s opinion lacks
reliability [such] that [the] opinion should not reach the trier of fact.” Of course, even though personal observations
are not excepted from Lanigan
analysis, in many cases personal observation will be a reliable methodology to
justify an expert’s conclusion. If the
proponent can show that the method of personal observation is either generally
accepted by the relevant scientific community or otherwise reliable to support
a scientific conclusion relevant to the case, such expert testimony is
admissible.[60]
The SJC held there was no evidence to demonstrate
that the expert used a reliable methodology to diagnosis the plaintiff as
suffering with MCS. Therefore, it
reversed the decision of the Appeals Court.
Pure opinion expert evidence
must, of course, meet certain foundational requirements. The expert must be qualified by education,
training and experience to render an expert opinion. Also, the material relied upon or considered by the expert in
forming the opinion must be of a type reasonably relied upon by experts in that
particular field in forming opinions, or inferences upon a subject. Further, there must be a sufficient
analytical connection between the material considered or relied upon and the
expert opinion itself.[61]
In Bailiff v. Manville Forest Products Corp.,[62] the
plaintiff brought an action against numerous chemical suppliers, alleging that
their products caused the plaintiff chronic asthma and bronchitis. The plaintiff’s treating physician supplied
an affidavit. The affidavit indicated that the plaintiff had no medical
problems before the alleged exposure, but after exposure he contracted asthma
and bronchitis. The affidavit stated that the chemicals likely caused the
plaintiff’s condition since the chemicals were known possible respiratory
irritants. The court rejected the physician’s causation testimony. The court first questioned “whether [the
doctor] possesses the necessary qualifications to render an opinion on the
issue of a causative link between the product of a defendant and [plaintiff’s]
medical condition.”[63] The court continued:
In this regard, there is
nothing in [the physician’s] affidavit to indicate that he has any skills,
training, knowledge, education or experience regarding any of the chemicals
manufactured by the defendants (other than that contained in the Material
Safety Data Sheets, discussed infra) . . .
There is no indication that [the physician] possesses any information
concerning exposure times or quantities of chemicals involved in [plaintiff’s]
exposures, or that he has knowledge concerning or has performed any tests that
might offer information about any cause and effect relationship between
exposure to particular chemicals and [the plaintiff’s] diagnosed conditions.[64]
Therefore, the court excluded the physician’s
opinion concerning causation and it granted the defendant’s motion for summary
judgment.
Similarly, in Elder v. Pacific Telephone & Telegraph
Co.,[65]
the plaintiffs offered the testimony of an architect about the custom and
practice of the construction industry.
The exclusion of this testimony was excepted to, and on appeal the court
held that even an expert witness would not be permitted to lapse into legal
commentary. The court stated:
Plaintiffs also called an
architect to testify as to the custom and practices in the construction
industry, and sought his opinion as to the Applicability [sic] to defendants of
certain construction safety orders relating to demolition work. The latter opinion was properly
excluded. While an expert witness may
properly testify as to custom and practice in construction safety, he may not
state interpretations of the law, whether it be of a statute, ordinance or
safety regulation promulgated pursuant to a statute.[66]
Maffei v. Northern Insurance Co.[67] also involved pure opinion
expert testimony. In Maffei the plaintiff owned a warehouse
facility in Berkeley, California where he stored numerous drums of various
chemicals used for the manufacture of dry-cleaning products. One of the drums caught fire and released
sulfur dioxide smoke. The plaintiff’s
insurance covered “hostile fires,” but it excluded other types of pollution
claims. The insurer denied coverage
based on the exclusion in lawsuits brought by third parties for personal injury
and property damage that alleged injury from exposure to the sulfur dioxide
smoke. The plaintiff sued the insurer
for a determination of coverage and alleged bad faith. The primary issue was whether the discharge
of sulfur dioxide was caused by the fire or from a non-fire-related chemical
reaction in the drum. The plaintiff had
a thermal engineering expert submit a declaration that concluded that there had
been a fire. The expert testified that
sodium hydrosulfite decomposes into flammable sulfur compounds when exposed to
small amounts of moisture and the heat generated from the decomposition could
have ignited the chemical compounds to produce emissions of sulfur dioxide gas
and smoke. The trial court struck the
expert’s testimony, holding that:
(1) the defendants
established that the pollution exclusion barred the plaintiffs’ claim; (2) no
evidence supported the plaintiffs’ claim that the hostile fire exception
applied, and (3) the plaintiffs failed to establish that a genuine issue of
material fact existed with regard to the application of the hostile fire
exception.[68]
The court struck the plaintiff’s declarations as
“unnecessary” under Fed. R. Evid. 702, and because one declaration
impermissibly asserted a legal conclusion that was unsupported. The Ninth Circuit Court of Appeals, in a 2
to 1 decision, reversed, holding it was an abuse of discretion to have struck
the expert’s testimony and noting that a material question of fact existed as
to whether a fire occurred within the drum.
Pure opinion expert
testimony has taken a variety of forms.
In Merit Motors, Inc. v. Chrysler
Corp.,[69]
an antitrust action, the plaintiffs relied on an expert that applied an
“inherent” economic effects theory concerning subsidies and other special
programs between Chrysler and its dealers.
The expert asserted that Chrysler dealers were being harmed in three
significant ways according to “standard economic theory.” First, the lower prices to fleet purchasers
resulted in more new cars sold to the fleets, many of which end up on the used
car market. Second, if Chrysler was unable to give subsidies it necessarily
would have to lower wholesale prices to dealers to maximize its profits. These subsidy programs would have the effect
of “squeezing” dealers between higher wholesale prices and lower retail prices. Third, a number of fleet purchasers are also
long-term leasing companies and are in direct competition with the Chrysler
dealers selling new cars. The expert
asserted the dealers were injured in their competition against the leasing
companies because the dealers did not receive subsidies and other benefits the
leasing companies were granted.
Chrysler argued that the expert’s theories were purely speculative. The plaintiffs claimed that their expert
merely applied “standard economic theory” to “a factual basis that is
uncontroverted.”[70] In affirming summary judgment for Chrysler,
the court noted:
[I]t is obvious that [the
expert] makes unsupported assumptions about the elasticities of demand in
various markets and that he virtually ignores the impact of the dominant forces
in the automobile market: General Motors and Ford. To hold that Rule 703 prevents a court from granting summary
judgment against a party who relies solely on an expert’s opinion that has no
more basis in or out of the record than [the expert’s] theoretical speculations
would seriously undermine the policies of Rule 56. We are unwilling to impose the fruitless expenses of litigation
that would result from such a limitation on the power of a court to grant
summary judgment.[71]
It is axiomatic that experts
must be properly qualified. Testimony
by an unqualified expert may constitute prejudice that requires reversal of a
jury verdict.[72] Further, an expert will not normally be
permitted to give an opinion that invades the province of the trier of
fact. Nevertheless, expert opinions can
be given that come very close to that line.
For example, in Nixon v. United
States,[73]
the defendant was convicted of multiple offenses, including assault with a
deadly weapon upon his live-in girlfriend.
The trial court held an in limine
hearing outside the presence of the jury and it ruled the government could
introduce expert testimony on battered woman syndrome (BWS), including “myths
about domestic violence,” “common patterns of battering,” and “common behavior
of victims of battering.”[74] An expert for the government testified about
BWS, despite the fact that she had not examined the defendant or his
girlfriend. Further, the expert did not
even know whether the girlfriend was abused at all, or if the defendant had
abused her, making clear that she was not providing an opinion concerning the
guilt or innocence of the defendant.
The appellate court affirmed the trial court’s decision to admit the
testimony.
Similarly, in Drevenak v. Abendschein,[75]
a medical malpractice case with competing experts on both sides, the trial
court weighed the expert testimony and ruled for the defendant, finding that
the testimony of the defense experts was more convincing, generally, because
they were better qualified. The court
explained that:
If you look at the
collective experience of these experts, it’s clear that the defense experts had
many more years of practice and experience in the areas that they were talking
about than [the plaintiff’s] experts.
And they also had a lot more experience in the number of cases that
they’d seen over the course of their practice compared to [the plaintiff’s]
experts.[76]
On appeal, the appellate court observed that the
plaintiff’s case did not relate to any novel scientific evidence or test or to
any unique, controversial methodology or technique. The case focused solely on the exercise of clinical judgment
based upon specialized medical knowledge.
The case did not fit the mold of one in which novel scientific evidence
or a unique controversial methodology or technique is involved. Therefore, the judgment of the trial court
was affirmed.
In affirming, the court
examined the standards in medical malpractice cases and it identified seven
legal principles that are important when assessing the sufficiency of proof for
a national standard of care proof.
First, the standard of care
focuses on “the course of action that a reasonably prudent doctor with the
defendant’s specialty would have taken under the same or similar
circumstances.” Second, the course of
action or treatment must be followed nationally. Third, the fact that District physicians follow a national
standard of care is insufficient in and of itself to establish a national
standard of care. Fourth, in
demonstrating that a particular course of action or treatment is followed
nationally, reference to a published standard is not required, but can be
important. Fifth, discussion of the
course of action or treatment with doctors outside this jurisdiction, at
seminars or conventions, who agree with it; or reference to “specific medical
literature” may be sufficient. Sixth,
an expert’s personal opinion does not constitute a statement of the national
standard of care; thus a statement only of what the expert “would do under
similar circumstances . . .” is inadequate.
Seventh, national standard of care testimony may not be based upon mere
speculation or conjecture.[77]
Therefore, it is the role of the trier of fact,
aided by vigorous cross-examination, to decide on the worth of the
opinion. In making a determination of
whether there is sufficient evidence to support a jury verdict, the court
should: (1) “consider the evidence most favorable to the prevailing party,” (2)
“assume that all conflicts in the evidence were resolved by the jury in favor
of the prevailing party,” (3) “assume as proved all facts which the prevailing
party's evidence tends to prove,” and (4) “give to the prevailing party the
benefit of all favorable inferences which reasonably may be drawn from the
facts proved.”[78]
The bottom line although is
that expert testimony is not binding on the trier of fact, and the trier of
fact is given considerable latitude in determining the weight to be given such
evidence. Therefore, an expert’s
testimony as to the standard of care does not conclusively establish the standard
of care; it is only evidence of that standard.
VI.
Scientific Expert Evidence
Some scientific principles,
laws and theories are so well established that the court may take judicial
notice of them without the introduction of expert evidence. For example, Charles’s Law[79]
and Boyle’s Law[80]
are accepted without question, as are many other laws of mathematics, physics
and other scientific fields. As the
scientific basis for expert evidence moves away from the clearly proven and
generally accepted areas of science, the courts are called upon to examine the
evidence and determine its reliability, and hence its admissibility. Exactly how that is to be done has been a
subject of controversy for decades.
In Richardson v. Richardson-Merrell, Inc.,[81] the Court of
Appeals unanimously affirmed the trial court’s grant of a motion for judgment
in favor of the defendant, notwithstanding a very large contrary jury verdict,
on the ground that the scientific basis for testimony of the plaintiff’s
experts was inadequate. The case, like
many others of its day, involved the ingestion of Bendectin by a pregnant woman
that allegedly resulted in birth defects in the baby.[82] Both the district court and the Court of
Appeals analyzed the evidence presented and came to the conclusion that the
verdict could not stand. The
plaintiffs’ sole expert[83]
admitted that there was no published work on Bendectin that concluded there is
a statistically significant association between Bendectin and limb reduction
defects of the type at issue in Richardson. The expert was able to reach his opinion
only by recalculating the available data.
The expert also rejected studies that had been published in
peer-reviewed scientific journals. At
the same time, the expert had neither published his own recalculations nor
offered them for peer review.
Under the Frye standard, “the proponent of a new
technology must demonstrate by a preponderance of the evidence that the
technology has been generally accepted in the relevant scientific community.”[84] As the Porter
court demonstrated, the issue is not validity, but consensus versus controversy
over a particular technique. If a
significant number of scientists publicly oppose a new technique as unreliable,
then it does not pass muster under Frye.[85] The same result should be reached under the
“gatekeeper” standard enunciated in Daubert.
VII.
Non-Scientific Expert Evidence
“Non-scientific” is really a
somewhat misleading term. It is used to
define processes, tests and procedures that are not typically the subject of
articles in peer-reviewed journals in the sense that, for example, the
teratogenic effect of chemicals or drugs might be. Engineering studies, construction material standards, and many
environmental analysis techniques fall into the non-scientific realm, even
though they are directly related to scientific inquiry and analysis. For example, groundwater monitoring, aquifer
flow rate and direction, and chemical analysis of potable and non-potable water
would be considered non-scientific areas for the purpose of applying Kumho Tire and its progeny.
VIII.
Expert
Testimony in State Courts
Most litigation takes place
in state courts, not federal courts.
While many states follow the federal expert evidence trilogy, many have
established their own rules governing the admission of expert testimony. Some continue to follow Frye, some follow Daubert,
and some have their own rules governing the admissibility of expert
testimony. Further, not all states have
even established precedent. The
following are recent authorities by those states that have expressed views on
the admissibility and standards for expert evidence.
A. Alabama
The Kumho Tire decision had its genesis in Alabama. Carmichael
v. Samyang Tires, Inc.[86]
was the forerunner to the Supreme Court decision in Kumho Tire. In Carmichael the district court believed
correctly that it should act as a reliability “gatekeeper” under Daubert v. Merrell Dow Pharmaceuticals, Inc.,[87]
and Fed. R. Evid. 702. The trial judge
ruled that the court must ensure scientific testimony is not only relevant, but
reliable. The court noted that Daubert discussed four factors –
testing, peer review, error rates, and “acceptability” in the relevant
scientific community – that might prove helpful when determining the
reliability of a particular scientific theory or technique. The court went on to find that those factors
argued against the reliability of the expert’s methodology. On the plaintiffs’ motion for
reconsideration, the court agreed that Daubert
should be applied flexibly. In
addition, its four factors were simply illustrative with other factors
available to argue in favor of admissibility, however, the court affirmed its
earlier order because it found insufficient indications of the reliability of
the expert’s methodology. The Eleventh
Circuit reversed, holding that the district court had erred as a matter of law
in applying Daubert. It held that Daubert was limited to its specific scientific context and that the
Daubert factors did not apply to
skill- or experience-based testimony.
The Supreme Court subsequently reversed the Court of Appeals in the Kumho Tire decision.[88]
Neither Carmichael nor the later Kumho
Tire decision answered the question of whether Alabama would adopt the
federal expert evidence trilogy. In
fact, it did not do so. In Southern Energy Homes, Inc. v. Washington,[89]
the Alabama Supreme Court adhered to the Frye
test and declined to adopt Daubert as
the standard for the admission of scientific expert testimony in Alabama.
Southern Energy Homes, Inc. was then followed closely by the case of Courtaulds Fibers, Inc. v. Long.[90] In Courtaulds
the plaintiff Long lived and kept horses on property near the defendant’s
fabric manufacturing plant. He sued
Courtaulds alleging that the carbon
disulfide used by the defendant prevented him from enjoying his property and
the plant caused death and injury to his horses. Prior to trial, the court dismissed the plaintiff’s claim for
punitive damages. The jury returned a
verdict against the defendant and the defendant appealed. On appeal the plaintiff cross-appealed the
punitive damage claim. The trial court
held the plaintiff’s expert testimony was admissible under the Frye test, and the expert witness was
not required under Ala. R. Evid. 702 - that tracks its federal counterpart - to
have scientific literature to support his opinion.
The Alabama Supreme Court
reversed, finding the nuisance and negligence claims were not supported by
substantial evidence. The case was
remanded for a new trial on the trespass claim only. The court noted that it has not abandoned the “general
acceptance” test in Frye, and that Daubert had not been adopted as the
standard in civil cases. However, the
Alabama Defense Lawyers Association (ADLA) filed an amicus curie brief in
support of the defendant. The ADLA
sought for the court to abandon the Frye
test and adopt the Daubert
standard. However, the court declined
to consider the issue because neither party in the case raised it. The court noted that it “will not decide a
question presented by amicus curiae which was not presented by the parties to
the cause, and will leave the question for decision when properly raised and
presented.”[91]
B. Alaska
Alaska has not definitively indicated how it will handle the admission of expert evidence. In Bieghler v. Kleppe,[92] the Ninth Circuit Court of Appeals reversed a grant of summary judgment against the plaintiffs in an action against the government. In Bieghler the plaintiff’s expert reconstructed the accident that occurred and opined that it was caused by defective lighting in a tunnel built and maintained by the government. The court observed that when the expert evidence concerning the cause of the accident supports an inference that defendant’s negligence was more probably than not the