The federal rule of evidence governing expert testimony — Rule 702 — just saw its most significant change in almost 25 years. The new Rule 702, which went into effect Dec. 1, 2023, gives litigants important new tools for keeping unreliable opinions away from juries.
What Changed?
The changes to Rule 702 are shown below, with additions underlined and deletions indicated as strike-thru text:
Rule 702. Testimony by Expert Witnesses
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:
- 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;
- the testimony is based on sufficient facts or data;
- the testimony is the product of reliable principles and methods; and
- the
expert has reliably applied expert’s opinion reflects a reliable application of the principles and methods to the facts of the case.
Why It Matters: Gatekeepers or Turnstiles?
These changes clarify and emphasize the judge’s role as a true gatekeeper for expert testimony. In practice, courts too often set a low bar for admissibility and cast substantive challenges as things the jury can consider in deciding how much weight to give the expert. Under this approach, only the most obviously flawed expert testimony ends up being excluded. The new Rule 702 aims to correct that practice in two ways.
First, the new rule clarifies that the proponent of expert testimony has the burden of establishing all four criteria — parts (a) through (d) — by a preponderance of the evidence. In other words, it’s not enough to present some evidence that an expert’s methods are reliable. The proponent has to prove that the expert’s methods are “more likely than not” reliable.
Second, the new language requires a tighter connection between experts’ opinions and the methods they use. The idea here is for courts to be more watchful of experts who exaggerate the conclusions that can be drawn from applying a given method. In the past, courts often viewed this issue as a classic topic for cross-examination. But the new rule emphasizes a judge’s role in first determining whether a specific opinion is “more likely than not” supported by an expert’s methodology.
How’s It Going?
It’s too early to tell just how much difference the new Rule 702 will make. Several courts have cited the new Rule 702 in excluding expert testimony, but at this early stage, no court has found the new language decisive on the question of admissibility. Still, one of the most common responses when a party’s expert is challenged is to say that any concerns can be explored on cross-examination. The amended language goes a long way toward undermining that argument, so expect to see fewer experts make it through the Rule 702 gate.
Aside from trials, the new Rule 702 is also important for class actions. While there is a split on this issue, most circuits require that expert testimony satisfy Rule 702 before it can be considered on class certification. If these changes lead to a more rigid application of Rule 702, it should be easier for defendants to defeat class certification.
Look out for future updates as courts wrestle with the implications of the new Rule 702.
