Relevance and Reliability: What All Expert Testimony Needs
By Michael Woodson

Background

Courts have long recognized expert witnesses’ potential to persuade, confuse and even mislead a fact finder and have attempted to craft safeguards against “junk science.” In 1923, the Federal District Court for the District of Columbia issued its opinion in Frye v. United States, acknowledging a receptiveness to expert testimony if deduced from well-organized scientific principle.1 In Frye, the defendant attempted to use an expert to establish that truth is spontaneous and the “utterance of a falsehood requires a conscious effort, which is reflected in the blood pressure.”2 (We litigators would likely have much less to do if this methodology was found reliable.) The court held that expert testimony on scientific matters will be admitted if based on “generally accepted” standards in a particular field.3

In 1993, the U.S. Supreme Court rejected the “generally accepted” standard for scientific evidence.4 The court found the adoption of the Federal Rules of Evidence, specifically Rule 702, required a new analysis.5 In Daubert v.  Merrell Dow Pharmaceuticals, the court installed the trial judge as a “gatekeeper” responsible for determining the relevance and reliability of expert testimony.6 The trial court must conclude that the proposed testimony will “assist the trier of fact.”7 If so, the court must then determine whether the expert’s methods are reliable.8 (This inquiry should not be confused with whether the expert’s opinions are credible or believable.)

The U.S. Supreme Court further expanded use of the standard in Kumho Tire Co. v. Carmichael.9 While the Daubert analysis focused on “scientific knowledge,” Kumho Tire held that the reliability requirement applied to all expert testimony, including opinions based on “technical” or “other specialized knowledge.”10

It did not take long for the Daubert analysis to reach Oklahoma’s criminal courts. In 1995, the Oklahoma Court of Criminal Appeals adopted the Daubert standard in Taylor v. State.11 Taylor involved the admissibility of complex analysis of DNA matching. The Court determined trial judges, not jurors themselves, would act as gatekeepers ensuring that scientific evidence is both reliable and relevant.12 The court found the Daubert standard provided the necessary structure to consistently make these determinations, while giving the trial judge the flexibility to address the unique facts of individual cases.13 In 2000, the Oklahoma Court of Criminal Appeals again followed the U. S. Supreme Court’s lead and expanded the Daubert analysis to expert testimony involving “technical” or “other specialized” knowledge.14

The Daubert analysis was not so quickly embraced in the civil arena. It was not until 2003 that the Oklahoma Supreme Court adopted the Daubert standard.15 In doing so, the court noted the similarities between the Oklahoma Evidence Code and the Federal Rules of Evidence.16 The court found that the trial judge’s gatekeeper function was inherent in Rule 702 and Daubert is “but a refinement of this role.”17 The court also found that the Evidence Code did not distinguish between “scientific,” “technical” or “other specialized knowledge,” and therefore, the standard would apply to all expert testimony.18

Relevance

The first step in the Daubert analysis is “relevance.” Rule 702 permits expert testimony when it will “assist the trier of fact.”19 As a practitioner, it may be easy to overlook this step when it comes to an otherwise qualified expert. However, it can be critical.

Take the example of a qualified toxicologist in a “dram shop” case.  The toxicologist has access to the results of a blood alcohol test conducted after an automobile accident. However, the test did not happen until two hours after the driver left the defendant’s bar. From the test results and other known variables, the expert is able to “extrapolate back” and opines that the driver had a blood alcohol level of 0.21 two hours before the post- accident test. The driver was legally intoxicated when he left the bar.

The blood test seems reliable. The toxicologist’s methodology in performing his “extrapolation” is tried and tested. However, in deposition, the expert testifies that alcohol affects people differently and he can not testify to a reasonable degree of certainty how the driver would have behaved with a 0.21 blood alcohol level.

At first glance the expert’s testimony may seem relevant. He is quantifying alcohol consumption and the plaintiff claims the defendant served the driver too much alcohol. The testimony establishes the driver had a blood alcohol level exceeding the legal limit when he left the bar and when the accident happened. But does the testimony really “assist the trier of fact to determine a fact in issue”? After all, what is the critical factual issue in a “dram shop” case? The inquiry is not whether the driver was legally intoxicated when he left the defendant’s bar, it is whether he “appeared” intoxicated. While the expert’s opinions about blood alcohol levels may be reliable, they really don’t assist the jury with the critical issue. If the expert cannot reliably correlate the blood alcohol level with this particular driver’s “appearance,” the testimony may not “assist the trier of fact” and may even mislead the trier of fact. It is always important to analyze the specific issue the expert is addressing.

Reliability

If the court determines expert testimony will assist, the court must still conclude the expert’s methodology is reliable. Courts look to the following factors when determining reliability: 1) whether the theory or technique can be or has been tested; 2) whether the expert or technique has been subjected to peer review and publication; 3) whether there is a known or potential rate of error and whether there are standards controlling the technique’s operation; and 4) whether the relevant scientific community generally accepts the technique or theory.20 The court is not required to give each factor equal weight.21 The court may base its decision on a single factor or consider all the specific factors in determining reliability.22 Most importantly, the test is designed to be “flexible” and Daubert’s list of factors neither necessarily, nor exclusively, applies to every expert or in every case.23 Trial courts have broad latitude in wrestling with how to determine reliability and the ultimate determination of what is reliable.24

By its very nature, the reliability determination will be factually intensive. For the practitioner, this will obviously be the focus of significant discovery efforts once an expert is designated. While potentially expensive, the pursuit of written reports and expert depositions is indispensable in conducting the Daubert analysis.25

While an analysis of case law applying the Daubert standard is beyond the scope of this article, it would not take long to digest the published Oklahoma civil cases. There are not many. Fortunately Oklahoma’s civil appellate courts find persuasive value in Federal decisions applying similar federal rules. Further, while not bound by a Court of Criminal Appeals decision, the Christian court agreed with several decisions in the overall application of Daubert by the Oklahoma Court of Criminal Appeals. Therefore when confronted with issues regarding admissibility of expert testimony, guidance is available.

Conclusion

The decision to retain or oppose an expert will be factually intensive. However, there is some guidance on what is required for admissible expert testimony. Best of luck and may an unqualified, unreliable or unnecessary expert never cross your client’s path.

1. 293 F.1013 at 1014 (DC Cir. 1923).
2. Id.
3. Id.
4. 509 U.S. 579 (1993).
5. Id. at 587-588.
6. Id. at 589.
7. Id. at 591.
8. Id. at 593-594.
9. 526 U.S. 137 (1999).
10. Id. at 147.
11. 1995 OK CR 10, 889 P.2d 319.
12. Id. at 328.
13. Id. at 329-330.
14. 2000 OK CR 14, 8 P.3d 883.
15. Christian v. Gray, 2003 OK 10, 65 P.3d 591.
16. Id. at 597.
17. Id. at 599.
18. Id.
19. Fed. Rules of Evidence 702 and 12 O.S. §2702.
20. 509 U.S. 579, 595 (1993).
21. 526 U.S. 137, 141-142 (1999).
22. Id.
23. Id.
24. Id.
25. See 12 O.S. §3226(B)(3)

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Relevance and Reliability: What All Expert Testimony Needs
Published 79 OBJ 543 (March 8, 2008)