I revisit my favorite Maryland Appellate Blog topic, the admissibility of expert testimony in Maryland courts, because it continues to generate fresh, important questions for judges and practitioners. With the Court of Appeals formally adopting Daubert as the standard for construing Maryland Rule 5-702 in all state courts, see Rochkind v. Stevenson, 471 Md. 1 (2020), Federal Rule of Evidence 702 has become, for all intents and purposes, as relevant as Maryland Rule 5-702. This is so because courts cannot adopt Daubert without adopting FRE 702.
But the unusual historical interplay between the Supreme Court’s 1993 Daubert decision and the original FRE 702 can obscure FRE 702’s primacy in a Daubert analysis. The 2020 Rochkind decision — by nominally adopting "Daubert” rather than FRE 702 — similarly risks confusion if Maryland courts try to “apply Rochkind/Daubert." Maryland courts and practitioners must be clear-eyed that, in all expert challenges, they are now applying Maryland Rule 5-702 and FRE 702. And both rules continue to evolve.
How the Daubert tail came to wag the FRE 702 dog:
Recall how the watershed Daubert decision came to eclipse the rule of evidence that it construed. When Federal Rule of Evidence 702 was first adopted in 1975, most federal courts were already applying the Frye general-acceptance test. The original FRE 702 allowed witnesses with expertise "by knowledge, skill, experience, training, or education" to offer opinion testimony if their "scientific, technical, or other specialized knowledge will assist the trier of fact to understand the evidence or to determine a fact in issue." The judicially created Frye test (born in the D.C. Circuit in 1923) had required proponents of novel, scientific opinions to show that (at least) their underlying methodology was generally accepted in the relevant field.
It took the Supreme Court until 1993, 18 years after the adoption of FRE 702, to issue its Daubert decision, declaring that FRE 702 replaced the Frye general-acceptance test and instructing courts how to apply FRE 702 using five flexible Daubert factors. Without guidance on what the enactment of FRE 702, which covers all expert testimony, meant for the Frye test, which nominally covers only novel, scientific expert opinions, federal courts had to decide what, if anything, to do with Frye. Of the nine federal circuit courts that had published pre-Daubert opinions on Frye’s validity after FRE 702's adoption, seven had held that Frye survived. So, imagine the confusion that Daubert produced when it told these seven esteemed appellate courts that they had gotten it wrong.
The dramatic change in federal evidence law triggered by the Supreme Court's "Daubert trilogy" (Daubert 1993, Joiner 1997, and Kumho Tire 1999) created the rare dynamic where an existing federal rule of evidence had to be amended to incorporate subsequent judicial opinions that explained what the rule already meant. The 2000 amendments to FRE 702 explicitly incorporated the Daubert trilogy. As amended in 2000, FRE 702 retained the original language but was now explicitly conditioned upon whether "(1) the testimony is based upon sufficient facts or data, (2) the testimony is the product of reliable principles and methods, and (3) the witness has applied the principles and methods reliably to the facts of the case."
But, because Daubert captured the judiciary's attention in a way that FRE 702’s enactment never had, courts and practitioners have become conditioned to "applying Daubert" case law rather than applying FRE 702 — which is exactly what Daubert instructed us to do in the first place. Thus, we have "Daubert hearings" to argue “Daubert briefs” to determine whether an expert's proffered opinions satisfy "Daubert’s requirements." This nomenclature is dangerously misleading because Daubert's core lesson is that Federal Rule of Evidence 702 — not incompatible judicially created rules, like Frye — controls the admission of expert testimony. So, a Daubert hearing should not "apply Daubert" as much as it should apply FRE 702.
Appreciating this, courts and commentators have increasingly emphasized the primacy of the rule itself over the case(s) construing it. In February, the Court of Special Appeals reminded state-court practitioners that, under Daubert, "Rule 5-702 remains the primary analytical rubric — the [Daubert] standard contributes to the application of the Rule, not the other way around." Matthews v. State, Case No. 3280, Sept. Term 2018 (Feb. 25, 2021) at 31. Similarly, a lecturer at a recent FRE 702 CLE implored attendees, "Stop calling them Daubert briefs!" Instead, we should file FRE 702/Md. R. 5-702 briefs in advance of (potential) FRE 702/Md. R. 5-702 hearings that yield FRE 702/Md. R. 5-702 rulings. FRE 702 should regain its status as the legal dog that wags its Daubert tail. Rule 5-702, once it is revised to incorporate Daubert standards, should not then defer to Daubert case law. And scheduling orders should now include deadlines for "Rule 5-702 motions" not "Daubert/Rochkind motions."
How FRE 702 is reclaiming its primacy:
The danger of applying a long line of case law instead of a black-letter rule is not merely that it is analytically backwards but that it invites error. Daubert case law has embraced so many soundbites and often-inconsistent phrases that practitioners can seemingly find anything they want to say in favor of precluding or admitting an expert. For every brief extolling a judge’s gatekeeping role to ensure that each expert has rigorously applied a reliable methodology, another brief reminds judges of the "liberal thrust" of Daubert admissibility and warns against usurping the role of the jury by weighing the evidence. Other cases simply beg the question by reminding courts that "shaky but admissible" expert opinions are admissible. (Of course, they are; "admissible" opinions are admissible by definition, regardless of the preceding adjective.) Many of the Daubert soundbites that continue to urge judges to favor admitting expert testimony and defer to juries originated in cases that precede the Daubert decision and — in some cases — precede even FRE 702 itself.
This erosion of Rule 702 standards through case law has not escaped the advisory committee to FRE 702, which is currently proposing further rule changes "to clarify and emphasize that the admissibility requirements set forth in the Rule must be established to the court by a preponderance of the evidence." The advisory committee explains that the clarification is needed because "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," bluntly concluding that these "rulings are an incorrect application of Rules 702 and 104(a)." 2021 Advisory notes. These amendments, thus, are mere clarifications of FRE 702, not substantive changes. FRE 702 has always required the proponent of expert testimony to satisfy each of Rule 702’s elements by a preponderance of the evidence. The same is true under Maryland Rule 5-702.
But Daubert case law shows that many courts have lost sight of this first principle. With the recent adoption of Daubert, Maryland courts should continue to uphold Rule 5-702 and now equally enforce FRE 702. In doing so, they must avoid slogans that suggest a lower evidentiary bar for expert testimony and require proponents of expert testimony to satisfy all elements of the Rule by a preponderance of the evidence.
This post originally appeared on the Maryland Appellate Blog, the blog of the Maryland State Bar Association Litigation Section.
 The Chair of the Subcommittee on Rule 702 for the United States Judicial Conference Advisory Committee on the Federal Rules of Evidence (Chief Judge Thomas Schroeder, United States District Judge for the Middle District of North Carolina) masterfully details the issue in his May 2020 Notre Dame Law Review Article, written in his personal capacity. See Federal Courts, Practice & Procedure: Toward A More Apparent Approach To Considering The Admission Of Expert Testimony, 95 Notre Dame L. Rev. 2039 (2020).
 As just one example (and there are many in every federal circuit), the Eighth Circuit — less than a month ago — rejected an appellant's challenge to the trial court's admission of expert testimony for an insufficient factual basis, invoking language that preceded Daubert and deferring the issue to the jury:
To the extent [defendant] disagreed with the underlying medical opinions about the scope of [plainitff's] injuries and related difficulties, he was free to challenge them through cross-examination at trial, which he did. See Hose v. Chi. Nw. Transp. Co., 70 F.3d 968, 974 (8th Cir. 1995) ("As a general rule, the factual basis of an expert opinion goes to the credibility of the testimony, not the admissibility, and it is up to the opposing party to examine the factual basis for the opinion in cross-examination." (quoting Loudermill v. Dow Chem. Co., 863 F.2d 566, 570 (8th Cir. 1988))).
Masters v. City of Indep., Nos. 19-2199, 19-2242, __ F.3d __, 2021 U.S. App. LEXIS 15861, at *20, 2021 WL 2148494 (8th Cir. May 27, 2021) (emphasis added). Not surprisingly, the quoted 1988 Loudermill opinion, which preceded Daubert, cites an opinion from 1969, before FRE 702 was enacted. See Loudermill, 863 F.3d at 570 (citing Twin City Plaza, Inc. v. Central Surety & Ins. Corp., 409 F.2d 1195, 1203 (8th Cir. 1969), for "general rule" that "the factual basis of an expert opinion goes to the credibility of the testimony, not the admissibility"). These statements are "are an incorrect application of Rules 702 and 104(a)." 2021 Advisory notes.