A Practical Guide To Daubert

Chilivis Grubman Dalbey Warner, LLP
3127 Maple Drive, N.E.
Atlanta, GA 30305
(404) 233-4171

While there is considerable controversy swirling around Daubert v. Merrill Dow Pharmaceuticals, 509 U.S. 579 (1993), Kumho Tire Co. v. Carmichael, 526 U.S. 137 (1999), and General Electric Co. v. Joiner, 522 U.S. 136 (1997), it is a fact of life for trial lawyers that expert testimony in federal court must meet the so-called “gatekeeper” requirements.

Statistics suggest that “judges may exercise more control over expert evidence post-Daubert than was done in the pre-Daubert times.” Carol Krafka, et al., Judge and Attorney Experiences, Practices, and Concerns Regarding Expert Testimony in Federal Civil Trials,p. 15 (Federal Judicial Center 2002) (excerpted from Psychology, Public Policy, and Law 2002, vol. 8, no. 3, pp. 309-332 (2002).

Daubert and Kumho set out a number of factors for trial judges to apply to determine whether an expert opinion is based on reliable principles and methodology. Before allowing a jury to hear and see expert testimony, the trial judge must ask questions like:

  • Has the expert’s theory, technique, or methodology been tested?
  • Have papers validating the theory, technique, or methodology been published in peer-reviewed journals?
  • What is the error rate of the theory, technique, or methodology?
  • Are there standards controlling the technique’s, the theory’s, or the methodology’s application or operation?
  • Is the opinion based on sufficient facts and data?
  • Is the theory, technique, or methodology generally accepted in the scientific community?
  • Has the technique, theory, or methodology been used outside of litigation? Whether the expert is proposing to testify about matters growing naturally and directly out of research he/she conducting independent of the litigation, or whether he/she developed his/her opinion expressly for purposes of testifying?Advisory Committee Notes, 2000 Amendments, Rule 702
  • Whether the expert is being as careful as he would be in his/her regular professional work outside his/her paid litigation consulting? Advisory Committee Notes, 2000 Amendments, Rule 702
  • Has the expert applied his/her theory, technique, or methodology reliably to the facts of the case? Does the opinion “fit” the facts of the case? See, e.g., Joiner v. General Electric, 864 F.Supp. 1310, 1320-1322 (N.D.Ga. 1994)(Evans, J.), rev’d,78 F.3d 524, 534 (11th Cir. 1996), rev’d, 522 U.S. 136 (1997).
  • Has the expert improperly extrapolated, leaping from an accepted scientific fact or premise to an unfounded conclusion? See, e.g., Joiner v. General Electric, 864 F.Supp. 1310, 1326 (N.D.Ga. 1994)(“analytical gap . . . too wide”). Advisory Committee Notes, 2000 Amendments, Rule 702.
  • Has the expert relied on anecdotal evidence?
  • Has the expert merely relied on temporal proximity, in the absence of any scientific method?
  • Has the expert ruled out all other possible causes? Has the expert adequately accounted for obvious alternative explanations? Advisory Committee Notes, 2000 Amendments, Rule 702.
  • Whether the field of expertise claimed by the expert is known to reach reliable results for the type of opinion the expert would give. Advisory Committee Notes, 2000 Amendments, Rule 702. See, e.g., Sterling v. Velsicol Chem. Corp., 855 F.2d 1188 (6thCir. 1988) (rejecting testimony based on “clinical ecology” as unfounded and unreliable).

These factors are not rigid. Rather, the “trial court must have the same kind of latitude in deciding how to test an expert’s reliability, . . . as it enjoys when it decides whether or notthat expert’s relevant testimony is reliable.” Kumho, 526 U.S. at 152. When reviewing a trial court’s application of the Daubert and Kumho factors, courts of appeals are to apply the “abuse of discretion” standard when reviewing a reliability determination. Joiner, 522 U.S. 136.

These factors apply not only to expert witnesses, but also to machines applying scientific concepts. U.S. v. Lee, 25 F.3d 997 (11th Cir. 1994)(judgment vacated and case remanded to hold Daubert hearing to determine whether two machines used to detect trace amounts of drugs satisfied the Daubert factors or were too experimental).

The standard for obtaining a hearing under Daubert and Federal Rule of Evidence 104, is explained in a recent article in the Mercer Law Review:

“The Eleventh Circuit’s decision in United States v. Hansen [262 F.3d 1217 (11th Cir. 2001)], provides guidance on how to raise a Daubert challenge. In Hanson, defendants were convicted of conspiring to commit violations of various environmental laws. At trial, the government relied on expert testimony regarding employee exposure to hazardous substances. Prior to trial, the defendants moved to convene a Daubert hearing to challenge this testimony. The district court refused to convene the hearing. On appeal the Eleventh Circuit first noted that a district court’s denial to hold a Dauberthearing is subject to the abuse of discretion standard. The court, however, acknowledged that a district court “should conduct a Daubert inquiry when the opposing party’s motion for hearing is supported by ‘conflicting medical literature and expert testimony.”‘ The district court denied the motion to convene a hearing because the motion did not identify the source, substance, or methodology of the challenged testimony, and therefore, the district court concluded, there was nothing for the court to assess. The Eleventh Circuit agreed. The practice pointer to be taken fromHansen is that requests for Daubert hearings should be very detailed; should identify the source, substance or methodology of the challenged testimony; and should be supported with contrary data or testimony.”

53 Mercer L. Rev. 1399, 1406-07 (2002).

Local Civil Rule 26.2 requires Daubert motions to be filed “no later than the date that the proposed pretrial order is submitted.” Otherwise, “such objections will be waived.” LR 26.2C.

Controversy about Daubert/Kumho/Joiner swirls because of several issues raised by those decisions:

(1) “While the standards appear to be more stringent than what existed earlier, we do not know whether they have led to improvements in the quality of evidence admitted or to exclusion of evidence that should have been admitted.” Lloyd Dixon and Brian Gill, Changes in the Standards for Admitting Expert Evidence in Federal Civil Cases Since the Daubert Decision, The Rand Institute for Civil Justice (2001). However, according the Advisory Committee Notes for the 2000 Amendments to Rule 702, “A review of the case law afterDaubert shows that the rejection of expert testimony is the exception rather than the rule. Daubert did not work a ‘sea change over federal evidence law.'”

Plaintiff’s counsel routinely ask whether he/she even wants to “run the gauntlet” ofDaubert/Kumho/Joiner in federal court; or whether the state courts are a far friendlier forum. For instance, Georgia specifically rejected the Daubert test. Norfolk Southern R. Co. v. Baker, 237 Ga.App. 292, 294(1), 514 S.E.2d 448 (1999).[1]

Similarly, federal prosecutors often attempt to avoid Daubert/Kumho hearings by characterizing their experts as mere “summary witnesses” under Rule 1006 of the Federal Rule of Evidence. By doing so, they also avoid the disclosures required by Rule 16(a) (1) (G) of the Federal Rules of Criminal Procedure.

Rule 701 of the Federal Rules of Evidence was recently amended to prevent the government from using lay witnesses ostensibly “not testifying as an expert” to express opinions. A witness “not testifying as an expert” cannot express opinions “based on scientific, technical, or other specialized knowledge within the scope of Rule 702.” See, U. S. v. Figueroa-Lopez, 125 F.3d 1241 (9th Cir. 1997) (the results of the decision are essentially codified by the amendment to Rule 701).

A conviction was recently reversed by the Fifth Circuit where the government offered expert testimony under the guise of a Rule 1006 summary witness. U. S. v. Hart, 295 F.3d 451 (5thCir. 2002). “Under the guise of a “summary” presentation, the government introduced its sole witness who could explain to the jury the proper preparation of FHPs [Farm and Home Plan submitted to the Farm Service Agency].” 295 F.3d at 457. The “assumptions” contained within the “summary” were the equivalent of the witness’s opinions. The trial court observed, “Here I am concerned about the issue that is raised that, apparently, she would testify that this is the proper way to prepare this Farm and Home Plan from these. And I don’t know that’s a summary witness. That sounds more like an expert witness.” 295 F.3d at 457. The Fifth Circuit reversed because “defendant has been convicted through a judicial process which is defective in some fundamental respect, e.g., incorrect receipt or rejection of evidence.” 295 F.3d at 459.[2]

  1. Motions challenging expert testimony have vastly expanded the time and expense of litigation, although the Eleventh Circuit noted, “Daubert hearings . . . are almost always fruitful uses of the court’s time and resources in complicated cases involving multiple expert witnesses.” City of Tuscaloosa v. Harcros Chemicals, Inc., 158 F.3d 548, 564 n.21 (11th Cir. 1998) Many commentators believe Daubertcreated “mini-trials” and a proliferation of motions to exclude expert testimony.See, Salzburg, Martin and Capra, Federal Rules of Evidence Manual, 8th ed., vol. 3, 702.02[10], p. 702-50, 1.
  2. Different factors are applied depending on whether the expert opinion falls into the scientific area, e.g., causation in a toxic tort action like Daubert, or a non-scientific area,e.g., tire failure analysis by engineers in Kumho.
  3. Application of the Daubert/Kumho factors to “soft science”, e.g., opinions interpreting behavior, is more problematic than applying the factors to opinions analyzing data, “hard science.” Tyus v. Urban Search Management, 102 F.3d 256 (7th Cir. 1996)(noting that the Daubert factors do not neatly apply to expert testimony from a sociologist);U.S. v. Gold, 743 F.2d 800 (11th Cir. 1984)(legal expert allowed to testify about what claims are reimbursable under Medicare).
  4. It is often difficult for trial judges to understand technical areas of science. The Eleventh Circuit recognized this difficulty in Joiner where Circuit Judge Stanley F. Birch, Jr., argued in his concurring opinion:

    “In discharging the Daubert mandate, the trial court can enhance the record for appellate review by appointing an expert, under Fed.R.Evid. 706, to assist the court in evaluating proffered scientific evidence. Augmentation of the record with the testimony of a competent, independent and philosophically neutral Rule 706 expert focused upon evaluating the reliability of the proffered expert evidence will likely promote a more comprehensive and adequate ruling by the trial court. As complex scientific and technical evidence becomes more commonplace, in this ever-advancing computer age, the need for the trial court generalist to seek expertise in dischargingDaubert responsibilities becomes increasing evident and compelling.”Joiner v. General Electric Co., 78 F.3d 524, 534 (11th Cir. 1996), rev’d,522 U.S. 136 (1997).

Judge Birch’s insight is illustrated in Pipitone v. Biomatrix, Inc., 2001 WL 568611(E.D.La. 2001), rev’d, 288 F.3d 239 (5th Cir. 2002), where the trial court lacked a basic understanding of epidemiology, criticizing an infectious disease specialist because he “performed no epidemiological study in the instant case.” 288 F.3d at 245. The Fifth Circuit reversed, explaining “that such a study is not necessary or appropriate in a case such as this in which only one person is infected.” 288 F.3d at 246.

The difficulty trial courts face when applying Daubert/Kumho was illustrated recently in U.S. v. Plaza, 179 F.Supp.2d 492, vacated for reconsideration, 188 F.Supp.2d 549 (E.D. Pa. 2002). In Plaza, the trial court barred the government from presenting expert fingerprint testimony. The court’s application of the Daubert/Kumho factors was careful and learned. The Judge is a former law professor and Dean of both the Yale Law School and the University of Pennsylvania Law School.

The government moved for reconsideration while presenting live testimony from some of the world’s leading fingerprint experts. This new evidence revealed that the FBI had, in fact, conducted a considerable number of tests to determine the reliability of fingerprint evidence. The evidence answered two key Daubert/Kumho questions: The method had been tested; and the error rate was low.

Additionally, while the first decision in Plaza criticized fingerprint matching methodology for its subjectivity, the second decision took note of the fact the FBI uses the same standardized safeguards for matching latent to rolled prints as are used in the United Kingdom. Thus, the method is “generally accepted.”

In addition to fingerprint matching, courts have grappled with the application of Daubert/Kumho to other traditional investigative tools in criminal prosecutions. For instance, courts have reached inconsistent results concerning handwriting analysis. U. S. v. Mooney,315 F.3d 54 (1st Cir. 2002) (expert opinion admitted); U. S. v. Hidalgo, 229 F.Supp.2d 961 (D. Az. 2002) (forensic document examiner barred from testifying as to authorship). BeforeDaubert, handwriting analysis was admissible under the Fryegeneral acceptance standard.See e.g., U. S. v. Fleishman, 684 F.2d 1329, 1337 (9th Cir. 1982) (“It is undisputed that handwriting analysis is a science in which expert testimony assists a jury.”)

The application of Daubert/Kumho to field sobriety tests, and to hair and voice identification, has also brought results that would have been unheard of beforeDaubert. U. S. v. Horn, 185 F.Supp.2d 530 (D. Md. 2002) (field sobriety tests not admissible as direct evidence of intoxication or impairment); Williamson v. Reynolds,904 F.Supp.2d 1529, 1558 (E.D. Okla. 1995), rev’d on other grounds, Williamson v. Ward, 110 F.3d 1508 (10th Cir. 1997) (expert hair comparison excluded); U.S. v. Bahena, 223 F.3d 797 (8th Cir. 2000) (voice identification expert excluded). Bite mark testimony has also been excluded. Howard v. State, 701 So.2d 274 (Miss. 1997).

A good example of the application of Daubert is in the field of linguistics. In U.S. v. Evans,910 F.2d 790, 32 Fed. R. Evid. Serv. 495 (11th Cir. 1990), the court rejected the expert opinion of a linguistics expert proffered by the defense. The Court reasoned: “We have stressed that, in deciding whether to admit testimony, ‘a trial judge must be sensitive to the jury’s temptation to allow the judgment of another authority to substitute for its own.’United States v. Sorondo, 845 F.2d 945, 949 (11th Cir.1988).” 910 F.2d at 802.

The court concluded:

“In deciding not to admit the testimony, the [trial] court concluded that while a jury in an appropriate case might be aided by testimony from a linguistic expert, the case at bar was not appropriate for such testimony. The court based this conclusion on several grounds. First, it noted that the recordings and transcripts that formed the basis of Dr. Shuy’s conclusions were in evidence, had been played and read in court, and could be played and read again by the jury during deliberations. The court also found that the expert’s testimony would not assist the jury because the subject matter of the testimony, conversation, was one which could be expected to be within the general knowledge of jurors. Finally, the court found that the testimony could be confusing and misleading to the jurors because it took matters out of context and, in some instances, was in the nature of conclusions regarding the appropriate interpretations to make of the recorded conversations.

We hold that the district court acted within its discretion in excluding Dr. Shuy’s testimony.” 910 F.2d at 803.

In contrast, the government frequently offers linguistics evidence. For instance, in U.S. v. Ceballos, 302 F.3d 679, 686 (7th Cir. 2002), the court allowed to DEA agents to interpret code language used in recorded telephone conversations even though the conversations (translated to English) were originally in Spanish and neither agent spoke Spanish. The court noted the “ambiguous use of pronouns” in the conversations justified the expert testimony. 302 F.3d at 688.

In both Evans and Ceballos, the recordings and transcripts were in evidence, had been played and read in court, and could be played and read again by the jury during deliberations. Apparently, the court in Ceballos did not believe the “ambiguous use of pronouns” in the conversations was of a nature that could be expected to be within the general knowledge of jurors. The use of “code language” seems to be the key distinguishing factor between Evans and Ceballos. Otherwise, the courts seem to believe jurors can interpret the spoken English language for themselves.

For instance, in U.S. v. Gonzalez-Maldonado, 115 F.3d 9, 47 Fed. R. Evid. Serv. 174 (1st Cir.1997), the court held that it was error to permit an FBI agent to interpret words in recorded conversations that were not code words and that were clear statements that the jury could interpret for itself. The court reasoned: “By appearing to put the expert’s stamp of approval on the government’s theory, such testimony might unduly influence the jury’s own assessment of the inference that is being urged.” 115 F.3d at 17-18.


As courts often note, the application of Daubert/Kumho ultimately depends of the unique facts of each case. However, the apprehension of being subjected to a Daubert/Kumho motion (1) causes many plaintiff’s counsel to avoid federal court entirely, and (2) causes many prosecutors to characterize their specialty witnesses as “summary” witnesses rather than “experts.” Successes in the areas of handwriting, fingerprint comparison, hair analysis, linguistics, and field sobriety tests show that Daubert has, indeed, dramatically changed the law of expert testimony.

[1] The standard for admissibility of expert testimony in Georgia is set out in Harper v. State,249 Ga. 519, 525 (1982):

“We hold that it is proper for the trial judge to decide whether the procedure or technique in question has reached a scientific stage of verifiable certainty, or in the words of Professor Irving Younger, whether the procedure ‘rests upon the laws of nature.’ The trial court may make this determination from evidence presented to it at trial by the parties; in this regard expert testimony may be of value. Or the trial court may base its determination on exhibits, treatises or the rationale of cases in other jurisdictions.”

See also, Jordan v. Georgia Power Co., 219 Ga. App. 690, 693 (1995) (excluding expert testimony concerning alleged causation of non-Hodgkins’ lymphoma by electromagnetic fields from power lines).

[2] U.S. v. Johnson, 54 F.3d 1150, 1162 (4th Cir. 1995)( in the ordinary federal drug prosecution, neither a summary witness’s testimony nor a summary chart would be admissible under Rule 702); But see, U.S. v. Caballero, 277 F.3d 1235 (10th Cir. 2002) (FBI financial analyst allowed to “summarize” business records).