The sequestration of expert witnesses falls under Oregon’s Rules of Evidence, Rule 615. OR. REV. STAT. ANN. § 40.385 (West 2017). This rule allows the court to exclude a witness from the courtroom as to not hear the testimony of other witnesses upon request of a party or on the court’s own motion. Id. The rule has four exceptions and expert witnesses fall under the third exception. Id. The third exception is for “A person whose presence is shown by a party to be essential to the presentation of the party’s cause.” Id. If the party opposing the motion to exclude objects, discretion is given to the trial court to decide if the expert should be excluded. Id.