Judge Mercer was appointed to the Panel as a full-time legal judge in December 2023. After graduating law school, Judge Mercer clerked for a United States Magistrate Judge in Cleveland, Ohio, for two years. His subsequent private practice in Pittsburgh, Pennsylvania, included his work as a litigation partner for several national and international law firms, including K&L Gates, LLP; Norton Rose Fulbright US, LLP; and Nelson Mullins Riley & Scarborough, LLP. In that private practice, Judge Mercer focused on energy litigation, primarily in the oil and gas field. As a litigator, Judge Mercer routinely defended clients in state and federal courts, at the trial and appellate levels, including serving as trial counsel for numerous jury and non-jury trials. He also represented energy clients in administrative matters at the state and local levels.