Looking Back at 'Daubert'

Article, California LawyerOctober 2017


Almost 25 years ago, a key U.S. Supreme Court decision set the standard for the admissibility of expert testimony in federal court. Frank Wisehart looks back on that venerable precedent in California Lawyer.

As appeared in California Lawyer, October 9, 2017.

By: Frank Wisehart

While valuation experts are generally familiar with the concept that their litigation testimony is subject to challenge under the U.S. Supreme Court’s Daubert decision (see Daubert v. Merrell Dow Pharmaceuticals, Inc., 509 U.S. 579 (1993)), very few appraisers have read the decision or understand what the case was about. Since it is the norm today for expert testimony to be closely scrutinized, knowledge of the underlying facts and historical significance of Daubert is very beneficial. Let’s take a look back at how this key case came to dominate the admissibility of expert testimony under the Federal Rules of Evidence


In the beginning, there was Frye v. United States, 293 F. 1013 (D.C. Cir. 1923).

During the first quarter of the 20th Century, courts frequently heard testimony based on first-hand or direct observation. In other words, testimony pertained to what people saw, whether they could identify something, such as the speed of an automobile, and what they heard. Trial judges vetted the credibility of fact witnesses and determined what was allowed to be presented and what was not allowed to be presented. Accordingly, the trial court established itself as the gatekeeper to evidence.

The trial court landscape was evolving, however. A new trend in evidence was occurring: expert testimony. Experts presented no eyewitness accounts; they did not see or hear anything that happened. Rather, experts testified about what happened based on circumstantial data and the scientific methods they applied. They did not see the cars collide in an accident; instead they examined the length and pattern of skid marks to determine the rate of speed and direction of the automobiles based on scientific observation.

Trial judges, as gatekeepers, were faced with the task of trying to decipher which experts were, and which experts were not, allowed to present evidence in court. Complicating matters, judges could not possibly have enough knowledge about certain scientific matters to ascertain what to let in and what to exclude. In many proceedings, a standard of, “do you make a living doing what you intend to testify about” was often the determining factor in the admission or denial of expert evidentiary issues. Evidentiary rulings varied substantially from jurisdiction to jurisdiction.

And then suddenly, a sensational murder, a recanted confession and a systolic blood pressure machine focused media coverage on scientific evidence.

On the evening of November 25, 1920, in Washington, D.C., James Alfonso Frye, a former World War I private, shot and killed a prominent physician, Dr. Robert W. Brown in his office. On hearing the first shot fired, Dr. Jackson, who was visiting Dr. Brown at the time, went into the hallway and witnessed the fatal second shot. Frye fled the scene. Jackson pursued until Frye fired at Jackson. Dr. Jackson, who did not know Frye, provided the police with a general description of the murderer.

Seven months later, on August 16, 1921, Frye was picked up by the D.C. police on a burglary charge. After five days in custody, Frye confessed to the murder of Dr. Brown. At his trial, Frye claimed he was tricked into a confession. He had an alibi; that he was visiting Mrs. Essie Watson the evening of the murder. But, Mrs. Watson’s ill health prevented her from testifying. A trial continuance to accommodate Mrs. Watson was denied. So, Frye’s attorney, Richard V. Mattingly, turned to science for help. Mattingly sought to enter into testimony the results from a systolic blood pressure test administered by Dr. William Moulton Marston. Dr. Marston was prepared to testify that, based on the results of his systolic blood pressure device, Frye was telling the truth when he stated he did not murder Dr. Brown.

A heated argument before District Judge William McCoy and the jury ensued over the admissibility of Frye’s confession, Dr. Marston’s lie detection results testimony, and the reliability of the scientific evidence.

(The jury was present during evidentiary arguments and learned firsthand of Dr. Marston’s lie detection results that were ultimately precluded from being placed on the record. After deliberation, the jury reduced Frye’s premeditated murder charge to second degree murder. Thus, the lie detector may have spared Frye’s life. Later, procedural rules were enacted to prohibit juries from hearing evidentiary admittance arguments.)

The confession stood, the lie detector was out, and Frye spent the next 18 years in jail until his release in 1939.

But that is not Frye’s legal legacy, as the trial court’s decision to exclude Dr. Marston’s testimony and the test results was appealed to the District of Columbia Circuit Court of Appeals. The court affirmed in an opinion that was to set evidentiary standards for 70 years.

The appellate court applied a “general acceptance” reliability test to the admissibility of scientific evidence.

Now commonly known as the “Frye standard,” the appellate tribunal’s short opinion, written by Circuit Judge Josiah A. Van Orsdel, stated that:

“Just when a scientific principle or discovery crosses the line between the experimental and demonstrable stages is difficult to define. Somewhere in this twilight zone the evidential force of the principle must be recognized and 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.” Frye, supra, 293 F. at 1013.

To meet the Frye standard in court, scientific evidence must be “generally accepted” within its scientific community. This standard applies to scientific methods, procedures, principles and techniques.

Unfortunately, Frye as court’s science gatekeeper tilted evidentiary admissibility issues in favor of books, published reports, and judicial precedents for making reliability and general acceptance decisions. Reliability was demonstrated by offering scientific publications, judicial decisions, evidence of practical use, or testimony by scientists on their peers’ position regarding the evidence in question.

For decades, courts favored the Frye standard when faced with determining the admissibility of a wide array of scientific evidence. Often, new scientific evidence failed to survive these demanding requirements. Evidence laws varied from state to state and district to district and what was generally acceptable in one jurisdiction failed the same test in another jurisdiction. The common law rules were harsh in some instances and made little sense in others. A single, comprehensive set of rules was necessary to eliminate this rather complicated variance.


To address these issues, in 1965 Chief Justice Earl Warren appointed an advisory committee of 15 prominent trial lawyers, legal academics, and judges to draft a new set of rules—that standard we know today as the Federal Rules of Evidence (FRE). The FRE provide procedures and standards governing the admissibility of, evidence.

The advisory committee was special indeed. It was chaired by prominent trial lawyer Albert E. Jenner from Chicago. Other members included legendary defense counsel Edward Bennett Williams of Washington, D.C.; President Eisenhower’s former Solicitor General, Judge Simon E. Sobeloff of Maryland; and renowned Columbia Law School professor and U.S. District Court Judge, Jack B. Weinstein.

The U. S. Supreme Court promulgated drafts of the FRE in 1969, 1971, and 1972, but Congress exercised its right under the Rules Enabling Act to suspend implementation of the rules for further study. After a long delay blamed on the June 1972 Watergate Hotel break-in scandal, Congress allowed the FRE to become federal law in 1975.


As defined in FRE 102, the thrust of the FRE is to “secure fairness in administration, elimination of unjustifiable expense and delay, and promotion of growth and development of the law of evidence to the end that the truth may be ascertained and proceedings justly determined.” Among other things, the FRE were designed to serve as a guide for the judiciary in determining the procedure over and acceptance of scientific evidence in the courtroom. The rules themselves are punctuated by their brevity and concise writing style.

Key provisions relating to the admissibility of scientific evidence are found in FRE 401, 402, 702, 703, and 705.

Noticeably missing from the newly minted FRE was the Frye court’s “general acceptance” reliability standard. Instead, FRE 401 requires evidence to be relevant. It defines relevancy as evidence that “has any tendency to make a fact more or less probable than it would be without the evidence and the fact is of consequence in determining the action.” See FRE 401(a) and (b).

The relevancy requirement focuses on the probative value of the evidence to be admitted. In other words, does the evidence tend to prove the matter that is sought to be proven?

FRE 402 provides that all relevant evidence is admissible, except as otherwise provided by the Constitution, an Act of Congress, other provisions of the FRE, or by other rules prescribed by the Supreme Court pursuant to statutory authority.


FRE 702 discusses expert testimony. It states:

“A witness who is qualified as an expert by knowledge, skill, experience, training, or education may testify in the form of an opinion or otherwise if:

(a) the expert’s scientific, technical, or other specialized knowledge will help the trier of fact to understand the evidence or to determine a fact in issue;

(b) the testimony is based on sufficient facts or data;

(c) the testimony is the product of reliable principles and methods; and

(d) the expert has reliably applied the principles and methods to the facts of the case.”

Note the key use of the word “or” in the listing of the five requirements for how an expert may be qualified: knowledge, skill, experience, training, or education. Proficiency in any one of the five requirements qualifies an expert witness to testify. The key requirement of FRE 702 is that the expert must possess specialized understanding of the subject matter involved in the dispute.

We get a further gloss from the very next rule, as FRE 703 provides:

“An expert may base an opinion on facts or data in the case that the expert has been made aware of or personally observed. If experts in the particular field would reasonably rely on those kinds of facts or data in forming an opinion on the subject, they need not be admissible for the opinion to be admitted. But if the facts or data would otherwise be inadmissible, the proponent of the opinion may disclose them to the jury only if their probative value in helping the jury evaluate the opinion substantially outweighs their prejudicial effect.”

The thrust of this provision, according to the advisory committee notes, is to “bring the judicial practice into line with the practice of the experts themselves when not in court.”

To cite but one example, let’s consider a doctor. Her testimony about how she might treat a patient given firsthand observation, education, training, or research is an admissible opinion under FRE 703.

FRE 705 requires experts to disclose on cross-examination the facts and data used in forming their opinion. Stating the opinion is not enough; the expert must disclose how he or she formed that opinion and on what data it is based. This allows the cross-examiner an opportunity to explore the strength of the expert’s underlying opinion and to present competing views based on the same set of data.


Bendectin was a popular anti-nausea drug marketed to combat morning sickness during pregnancy. It was manufactured by Merrell Dow Pharmaceuticals, Inc. from 1956 until its withdrawal from the market in 1983.

In the 27 years during which Bendectin was sold, more than 33 million pregnant women used it to curb their nausea and vomiting. Its ingestion by pregnant mothers was later believed to cause significant birth defects including oral clefts, club foot, heart disorders, diaphragmatic problems, and limb malformation.

Bendectin thus became the subject of massive class action litigation, with over 2,000 claimants over a 15-year period. Despite an impressive track record in defense of Bendectin lawsuits, Merrell Dow tried unsuccessfully to invoke a $120 million class settlement for all claims in order to hedge its mounting legal defense costs. This failure left intact Merrell Dow’s continued exposure to individual lawsuits.

Jason Daubert and Eric Schuller were minor children born with serious birth defects. They and their parents sued Merrell Dow, alleging that the birth defects were the result of the mothers’ ingestion of Bendectin.

Plaintiffs offered the testimony of eight experts who concluded that Bendectin could cause birth defects. These experts cited epidemiological evidence, including animal-cell studies, live animal studies, and chemical-structure analysis to support their causation argument. Some of this analysis was based on a reinterpretation of previously conducted studies that concluded that Bendectin was not a cause of birth defects. Plaintiff counsel expected this evidence to be admitted under the FRE despite the fact that the expert’s work had not yet been published nor subjected to peer review. (To be sure, plaintiffs’ list of experts was impressive. It included Shanna Helen Swan, who received a master’s degree in biostatistics from Columbia University and a doctorate from the University of California at Berkeley. At the time of the trial, Dr. Swan was the chief of the section of the California Department of Health and Services that determines causes of birth defects.)

Merrell Dow was not to be outdone. The company employed Dr. Steven H. Lamm, a medical expert and consultant for the National Center for Health Statistics, to refute the plaintiffs’ claims. Dr. Lamm did not testify about the causes and effects of Bendectin on pregnancy nor about chemical effects on pre-natal fetus development. Instead, Dr. Lamm testified that there had been no published reports linking Bendectin to malformations in fetuses. He concluded that, therefore, maternal use of Bendectin during the first trimester of pregnancy had not been shown to be a human birth defect risk factor, and argued that the plaintiff’s methods had not yet been generally accepted. Accordingly, Merrell Dow’s counsel moved for summary judgment based on the 1923 Frye reliability standard of general acceptance. The district court granted Merrell Dow’s motion for summary judgment. Daubert v. Merrill Dow Pharmaceuticals, Inc., 727 F. Supp. 570 (S.D. Cal, 1989).

The trial judge, relying on the continued authority of the Frye standard, held that scientific evidence is admissible only if the principle on which it is based is sufficiently established to have “general acceptance in the field to which it belongs.” Since the petitioners’ studies were not published and had not been subjected to peer review, the court ruled that the evidence was inadmissible under the general acceptance doctrine. That ruling was upheld by the Ninth Circuit, which also cited Frye’s general acceptance standards. Daubert v. Merrill Dow Pharmaceuticals, Inc., 951 F.2d 1128 (9th Cir. 1991).

Plaintiffs then appealed to the U.S. Supreme Court.


In an opinion authored by Associate Justice Harry Blackmun, the Supreme Court held that Frye’s “general acceptance” standard is not a necessary precondition to admissibility of scientific evidence under Federal Rules of Evidence. The court also concluded that the FRE assign to trial judges the task of ensuring that expert’s testimony both rests on reliable foundation and is relevant to task at hand.

In ruling that Frye’s 1923 standard had been eclipsed by the FRE, Court held true to the core premise of Chief Justice Warren’s advisory committee: namely that all relevant evidence is admissible. The Daubert ruling cemented the recognition that it may well be appropriate for the court and jury to consider relevant, well-founded theories that are too new or of too-limited interest to meet Frye’s general acceptance requirement.

The Daubert decision dug deep into the FRE 702 factors regarding scientific process, methodology, and conclusion. Although the FRE address relevancy, the key concept of “reliability” was not codified within the rules. The Daubert decision helped clarify the rules concerning scientific testimony by incorporating some of Frye’s general acceptance standards. The court recognized that the Frye general acceptance standard could serve as an aid to the application of FRE 702’s methodology requirements by introducing a reliability standard into scientific methodology relative to:

  1. The proof of testing of the basic underlying hypothesis on which the technique rests.
  2. Whether the method has been subjected to peer review and publications.
  3. What is the known or potential error rate.
  4. Whether the method used is accepted methodology.
  5. The general acceptance of the technique used in the scientific community.

Nonetheless, the court watered down these reliability requirements by explicitly stating that they are not rigid and are to be flexibly applied.

“The inquiry envisioned by Rule 702 is, we emphasize, a flexible one. Its overarching subject is the scientific validity and thus the evidentiary relevance and reliability—of the principles that underlie a proposed submission. The focus, of course, must be solely on principles and methodology, not on the conclusions that they generate.” See Daubert, supra, 509 U.S. at 594-595.

Daubert has proven to be the most influential ruling in the last quarter century on the admissibility of expert testimony and scientific evidence. The decision provided courts with a framework for admitting scientific testimony that is both relevant and reliable. As science continues to teach us new things, we must look to future cases to further define the meaning, application, and reach of the landmark decision we casually refer to today as Daubert.


Frank A. Wisehart CPA, ABV, CFE, CVA, MAFF is a partner in the San Francisco office of RGL Forensics, a leading financial investigations company.

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