The sequestration of expert witnesses falls under Maryland’s Rules of Evidence, Rule 615. MD. CODE ANN., CTS. & JUD. PROC. § 5-600-615 (West 2017). This rule requires that if requested by a party, the court should exclude a witness from the courtroom such that it cannot hear the testimony of other witnesses. Id. The court can also order the exclusion of a witness on its own. Id. Additionally, a witness can continue to be excluded after it has testified if there is likelihood that it will be recalled to testify further. Id. The rule has five exceptions, and two of them apply to expert witnesses. The third exception is for “an expert who is to render an opinion based on testimony given at trial” and the fourth is for “a person whose presence is shown by a party to be essential to the presentation of the party’s cause, such as an expert necessary to advise and assist counsel.” Id. Generally, a request for sequestering a witness should be granted if it is made before testimony begins unless the witness falls under an exception provided by the rule. Tharp v. State, 763 A.2d 151 (Md. 2000). However, the discretion as to whether to sequester a witness once another witness has begun testifying is given to the trial court to decide based on the facts. Id.
