The sequestration of expert witnesses falls under the Federal Rule of Evidence 615. FED. R. EVID. 615. This rule requires that when requested by a party or when the court instructs, witnesses should be excluded from the courtroom as to not hear the testimony of other witnesses. Id. The rule has four exceptions for individuals that should not be excluded, and expert witnesses are under exception (3) of Rule 615. Id. This exception is for “a person whose presence a party shows to be essential to presenting the party’s claim or defense.” Id. The party attempting to keep its expert from being sequestered bears the burden of showing that the exception applies. U.S. v. Olofson, 563 F.3d 652 (7th Cir. 2009). Further, Rule 703 of the Federal Rules of Evidence is not an automatic ban on sequestering expert witnesses. Id. The party that does not want its witness sequestered has to show that it is “essential” to the presentment of that party’s case that their expert is in the courtroom and not sequestered. Id. And, wanting one’s expert to be able to deny or rebut statements made by other experts is not sufficient enough of a reason to stop a sequestration request. Id.
In another case, it was noted that the main reason for Rule 615 is fact witnesses, so it is likely that experts will frequently fall within the exception of the rule and not be sequestered. Opus 3 Ltd. v. Heritage Park, Inc., 91 F.3d 625 (4th Cir. 1992). However, it is left to the trial judge to determine on a case-by-case basis. Id. If a party can show that the expert witness must hear all other testimony to render its opinions, then the exception will likely apply. Id. The sequestration was found to be improper in a case where the expert was not exposed to all information testified to by other parties because an expert’s testimony differed from the testimony that it provided in a report reviewed by the sequestered witness. Malek v. Federal Ins. Co., 994 F.2d 49 (2nd Cir. 1993). Furthermore, if the reports of other experts are not provided on a timely manner such that opposing party’s experts can read them before trial, sequestering the experts during the opposing expert’s testimony is not proper. U.S. v. Burgess, 691 F.2d 1146 (4th Cir. 1982).

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