§ Rule705 Disclosure of Facts or Data Underlying Expert Opinion
Rule705. Disclosure of Facts or Data Underlying Expert Opinion
(a) Disclosure of Underlying Facts. The expert may testify in terms of opinion or inference and give reasons therefor without first testifying to the underlying facts or data, unless the court requires otherwise. The expert may in any event be required to disclose the underlying facts or data on cross-examination.
(b) Objection. An adverse party may object to the testimony of an expert on the ground that the expert does not have a sufficient basis for expressing an opinion. Counsel may before the witness gives an opinion be allowed to conduct in the absence of the jury a voir dire examination directed to the underlying facts or data on which the opinion is based. If a prima facie case is made that the expert does not have sufficient basis for the expert's opinion, the opinion is inadmissible unless the party offering the testimony first establishes the underlying facts or data.