In the latest Weekly Wright Report:

The Rules Regarding Expert Testimony Have Been Amended – A Quick Look at the New Rule 702

Winter is upon us. The temperature is dropping, the lights are going up, and, of course, the new Federal Rule of Evidence 702 is coming into effect. As of December 1, 2023, Rule 702 has been amended, as ordered by the United States Supreme Court earlier this year. The new version of Rule 702 does not represent a major change, but any attorney who regularly conducts litigation involving expert witnesses should be aware of the changes and the way that federal courts are likely to interpret these changes.

The current version of Rule 702 is below, with added language from the recent amendment written in bold type:

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 the proponent demonstrates to the court that it is more likely than not that:

(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’s opinion reflects a reliable application of the principles and methods to the facts of the case

The two additions to Rule 702 may seem innocuous, but the Supreme Court does not adopt changes to the Rules lightly. Changing one of the Rules is a process that often takes up to three years. It involves a recommendation by the Advisory Committee, review by various bar associations, and a period of public comment. If the Supreme Court decides to move forward with an update to a Rule, there was almost certainly a good reason for doing so.

For the new Rule 702, the Committee notes indicate that the addition of the language regarding the preponderance of the evidence standard was due to the fact that “many courts have held that the critical questions of the sufficiency of an expert’s basis, and the application of the expert’s methodology, are questions of weight and not admissibility. These rulings are an incorrect application” of the Rules.  What this means is that the Committee amended the Rule to clarify that a court’s gatekeeping responsibility is limited to determining whether an expert witness has met the minimum standard for admissibility of their opinion, not to assess the weight of that opinion. The Committee noted, for example, that if an expert witness has a sufficient basis to support their opinion, but admits that they have not read many relevant studies, that should not be used as a basis for excluding the opinion altogether. The new Rule and its Committee Notes make clear that the reviewing court should not exclude an expert’s opinion in such a situation, but rather allow the finder of fact to consider that they have not read relevant reports as an attack on the weight of their testimony. The Committee noted that this may often result in two experts coming to different conclusions on the same set of facts – and both conclusions should be admissible. It is clear now under the new Rule that the court should not exclude one expert based on the weight of their opinions due to the fact that “Proponents do not have to demonstrate to the judge . . . that . . . their experts are correct. . . The evidentiary requirement of reliability is lower than the merits standard of correctness.”

The second change to Rule 702 was added, in the words of the Committee, “to emphasize that each expert opinion must stay within the bounds of what can be concluded from a reliable application of the expert’s basis and methodology.” The Committee notes on this point are particularly important with regard to the use by an expert of subjective methodology. The Committee noted that “forensic experts in both criminal and civil cases” should avoid asserting absolute certainty, and even avoid using the once-standard phrase “to a reasonable degree of scientific certainty,” if their methodology is subjective and thus “potentially subject to error.” While the Committee also noted that “nothing in the amendment imposes any new, specific procedures” and that the “standard does not require perfection,” this change to Rule 702 does seem to indicate that federal courts will be stricter about the content of an expert witness’s testimony, which will likely require litigators to spend additional time preparing and tailoring their expert’s testimony so that the expert does not accidentally make an objectionable claim.

Overall, no one can be sure of the full effect of the changes to Rule 702 until those changes have been thoroughly litigated. The most important thing for a litigator to remember is simply that the Rule itself has changed and that the voluminous case law having arisen out of Rule 702 in the past is no longer necessarily binding. If a litigator intends to rely upon a court’s previous ruling, or an otherwise-binding ruling from an appellate court, they should be prepared to explain why the changes to Rule 702 would not command a different result.