Rule 705. Disclosing the Facts or DataUnderlying an Expert’s Opinion
Unless the court ordersotherwise, an expert may state an opinion — and give the reasons for it —without first testifying to the underlying facts or data. But the expert may berequired to disclose those facts or data on cross-examination.
2011 Advisory CommitteeNote. – Thelanguage of this rule has been amended as part of the restyling of the EvidenceRules to make them more easily understood and to make style and terminologyconsistent throughout the rules. These changes are intended to be stylisticonly. There is no intent to change any result in any ruling on evidenceadmissibility. This rule is the federal rule, verbatim.
This rule isthe federal rule, verbatim. The substance of this rule was formerly found inRules 57 and 58, Utah Rules of Evidence (1971). The requirement that an expertdisclose the underlying facts or data for his opinion when cross-examined wasformerly found in Rule 58, Utah Rules of Evidence (1971). The discretion vestedin the trial judge to require prior disclosure of underlying facts or datashould be liberally exercised in situations where there has not been adequatediscovery in civil cases or disclosure in criminal cases.