Today, the New Jersey Supreme Court reconciled New Jersey’s framework for analyzing the reliability of expert testimony under N.J.R.E. 702 and the federal standard set forth in Daubert v. Merrell Dow Pharmaceuticals, Inc. The court incorporated the Daubert factors into New Jersey’s framework for civil cases, while simultaneously holding that the trial court appropriately played its gatekeeping role in excluding plaintiffs’ expert testimony regarding certain epidemiological studies.

In In re: Accutane Litigation (A-25-17) (079958) decided August 1, 2018, plaintiffs alleged that Accutane, a prescription acne medicine, causes Crohn’s disease, a chronic gastrointestinal illness. The mass tort litigation has spanned more than one decade. In that time, a number of epidemiological studies have been published, all concluding that there is no causal relationship between Accutane and Crohn’s disease. Plaintiffs’ experts rejected the epidemiological studies and asserted that Accutane can in fact cause Crohn’s disease. Following a Rule 104 pretrial evidentiary hearing, the trial court held that plaintiffs’ experts’ methodology was unsound because they did not interpret the relevant data and apply it to the facts in a manner consistent with other experts in the field, and excluded their testimony.

On appeal, the Appellate Division reversed, finding the plaintiffs’ experts’ methodology sound, and that they merely interpreted the data differently than defendants’ experts. The New Jersey Supreme Court granted certification to address whether the trial court properly excluded plaintiffs’ experts’ testimony, whether the Appellate Division employed the correct standard of review, and the larger issue of potentially clarifying New Jersey’s standard for assessing the reliability of expert witnesses in civil cases.

The Trial Court Properly Excluded Plaintiffs’ Experts’ Testimony

The court held that the trial court appropriately acted as gatekeeper in excluding plaintiffs’ experts’ testimony, and used the trial court’s decision making “to clarify and reinforce the proper role for the trial court as the gatekeeper of expert witness testimony.” The court stressed that “[t]he gatekeeping role requires care” and that although it is “[d]ifficult,” the trial court’s efforts in this role “must be rigorous.” The trial court explained its reasons for concluding that the experts deviated from core scientific principles. The experts made assertions demonstrably contrary to the recognized hierarchy of evidence generally accepted in the scientific community and “strayed from their own claimed methodology in reaching their conclusions.” “Ample evidence” supported the trial court’s finding that their testimony was unreliable, rendering its choice to exclude the evidence “unassailable.”

Abuse of Discretion Reigns on Appeal

Turning to the standard on appeal, the court reaffirmed that the abuse of discretion standard applies in the appellate review of a trial court’s determination to admit or deny scientific evidence on the basis of unreliability. The court clarified that the Appellate Division’s standard, that a reviewing court owes “somewhat less deference to a trial court’s determination” regarding expert testimony than other general issues, “is not appropriate in the context of a civil mass tort case.” Applying the proper standard, the court held that the Appellate Division erred in reversing the trial court’s “unassailable” decision to exclude plaintiffs’ experts’ testimony.

New Jersey Incorporates the Daubert Factors without Becoming a “Daubert Jurisdiction”

The court also incorporated Daubert’s factors “for use by our courts” because these factors “dovetail with the overall goals of our evidential standard and would provide a helpful – but not necessary or definitive – guide for our courts to consider when performing their gatekeeper role concerning the admission of expert testimony.” These factors include: (1) whether the scientific theory can be, or at any time has been, tested; (2) whether the scientific theory has been subjected to peer review and publication; (3) whether there is any known or potential rate of error and whether there exist any standards for controlling the technique’s operation; and (4) whether there does exist a general acceptance about the theory by the scientific community.

Although New Jersey courts may now use these factors when making reliability determinations, the court stopped short of declaring New Jersey a “Daubert jurisdiction.” In light of the varying approaches taken by the circuits and state courts when applying Daubert factors, the court was “hesitant to embrace the full body of Daubert case law.”

The court clarified that its “view of proper gatekeeping in a methodology-based approach to reliability for expert scientific testimony” requires the proponent to demonstrate that the expert applies a “scientifically recognized methodology in the way that others in the field practice the methodology.” If a proponent fails to demonstrate the methodology’s soundness, “the gatekeeper should exclude the proposed expert testimony on the basis that it is unreliable.”

Structurally, the decision does exactly what Supreme Court decisions should do—it clarifies an important area of the law applied every day in New Jersey courts. Substantively, it strengthens the commitment of New Jersey courts to having tort cases decided only on the basis of reliable evidence. And practically, it substantially increases the precedential value of the wide body of gatekeeping case law decided in Daubert and Daubert-like jurisdictions.