U.S. Supreme Court

Case Status


Docket Number



Cert. Denied


Questions Presented

Whether the requirements for the admissibility of expert testimony in Federal Rule of Evidence 702 and the Supreme Court's decision in Daubert v. Merrell Dow Pharmaceuticals, Inc., 509 U.S. 579 (1993), apply with full force to expert testimony offered in connection with class certification.

Case Updates

Case dismissed

April 11, 2013

U.S. Chamber files amicus brief addressing evidence standards for class certifications

January 17, 2012

NCLC urged the court to take this case and rule that in class certification disputes at the trial court level, expert testimony can be relied upon only if it has been subject to full review according to the standards established in Daubert and Rule 702 of the Federal Rules of Evidence. In this case, the district court relied upon expert opinions in certifying a class action suit against Zurn Pex, Inc., while candidly acknowledging that the opinions might flunk the Daubert test and “may not be admissible” at trial. In its amicus brief, NCLC argued that the lower court’s decision—and the Eighth Circuit’s subsequent affirmation—dramatically lowers the bar for certification and will encourage a proliferation of meritless claims. The decisions conflict with several Circuit Court decisions, and with the Supreme Court decision Wal-Mart v. Dukes. If allowed to stand, it would effectively delegate the class-certification decision to party-appointed experts while eliminating a key safeguard to prevent junk science from entering federal courts.

Case Documents