Supreme Court of the United States · Official docket →
Union Carbide Corporation, et al. v. Lee Ann Sommerville
Paid petition · United States Court of Appeals for the Fourth Circuit, No. 24-1491 · judgment August 18, 2025
Before the decision, well below the 4.1% base rate, with no standout signals pointing toward a grant.
Question presented
Whether, under Federal Rule of Evidence 702, challenges to the factual basis of an expert witness’s testimony always go to the weight of the evidence rather than to admissibility, as the First and Fourth Circuits hold, or whether such challenges go to weight only if a court first finds it more likely than not that an expert has a sufficient basis to support the testimony, as the Fifth, Sixth, Eighth, Ninth, and Federal Circuits hold.
Counsel of record
For petitioner
Donald B. Verrilli Jr.
Munger, Tolles & Olson LLP
For respondent
Joshua Michael Autry
Morgan & Morgan
Case
Conference history
Distributed for 2 conferences
Amicus briefs
3 cert-stage
Proceedings
- May 26 2026Petition DENIED. Justice Alito took no part in the consideration or decision of this petition.
- May 18 2026DISTRIBUTED for Conference of 5/21/2026.
- Apr 22 2026DISTRIBUTED for Conference of 5/14/2026.
- Apr 21 2026Reply of Union Carbide Corporation & Covestro LLC not accepted for filing. (To be resubmitted April 23, 2026)
- Apr 21 2026Reply of petitioners Union Carbide Corporation, et al. filed. (Resubmitted) (Distributed)
- Apr 06 2026Brief of respondent Lee Ann Sommerville in opposition filed.
- Mar 06 2026Brief amici curiae of The Chamber of Commerce of the United States of America, et al. filed.
- Mar 04 2026Brief amicus curiae of Atlantic Legal Foundation filed.
- Feb 17 2026Motion to extend the time to file a response is granted and the time is extended to and including April 6, 2026.
- Feb 17 2026Brief amicus curiae of Washington Legal Foundation filed.
- Feb 16 2026Motion to extend the time to file a response from March 6, 2026 to April 6, 2026, submitted to The Clerk.
- Feb 02 2026Petition for a writ of certiorari filed. (Response due March 6, 2026)