The sequestration of expert witnesses in Pennsylvania falls under Pennsylvania’s Rules of Evidence, Rule 615. PA. STAT. AND CONS. STAT. ANN. § 615 (West 2017). This rule gives the court the authority to sequester a witness to not hear other witness testimony if a party requests so or the court orders. Id. The rule has four exceptions of individuals that cannot be sequestered. Id. The third exception applies to experts, and is for “a person whose presence a party shows to be essential to presenting the party’s claim or defense.” Id.