On October 2, 2024, the NAM filed an amicus brief urging the 7th Circuit to affirm a trial court decision excluding the plaintiffs’ expert’s testimony. In this multidistrict litigation, over 5,000 plaintiffs sued manufacturers alleging that they developed Parkinson’s disease due to their exposure to the herbicide paraquat. The Southern District of Illinois granted summary judgment for the defendants after carefully evaluating and rejecting the opinions of plaintiffs’ sole general causation expert. Plaintiffs have appealed that decision to the 7th Circuit.
We argue that the district court properly performed its gatekeeping function in excluding the plaintiffs’ expert testimony. We ask the Court to take this opportunity to reaffirm the court’s gatekeeping role and the standards under the amended Rule 702 for admissibility of expert testimony—namely, the proponent must establish by a preponderance of the evidence that the expert’s opinion meets the applicable indicia for reliability, which the plaintiffs did not due in this case. All manufacturers have an interest in keeping junk science out of the courtroom.