Rule 705 DISCLOSURE OF FACTS OR DATA UNDERLYING EXPERT OPINION

• Jurisdiction: Colorado

Rule 705. Disclosure of Facts or Data Underlying Expert Opinion

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.

(Federal Rule Identical.)

Source: Entire rule amended and effective November 16, 1995.

COMMITTEE COMMENT

Although the present rule is contrary to Colorado case law, the Committee believes it to be the better view. The reasons for the retention of the proposed Federal rule as it is presently written are as follows. First, the rule does not disturb the requirement for a proper foundation for expert opinions. City and County of Denver v. Lyttle, 106 Colo. 157, 103 P.2d 1 (1940). Secondly, the elimination of the requirement for preliminary disclosure of underlying facts or data has the effect of reducing the need for hypothetical questions, a goal which has been sought by a number of states. Thirdly: "If the objection is made that leaving it to the cross-examiner to bring out the supporting data is essentially unfair, the answer is that he is under no compulsion to bring out any facts or data except those unfavorable to the opinion. The answer assumes that the cross-examiner has the advance knowledge which is essential for effective cross-examination. This advance knowledge has been afforded, though imperfectly, by the traditional foundations requirement." Advisory Committee's Notes, Proposed Federal Rules. See also, Archina v. People, 135 Colo. 8, 307 P.2d 1083 (1957). Finally, it is clear that there is built-in safeguard in the discretionary power of the court to require prior disclosure.

ANNOTATION

Law reviews. For article, "Opinion Testimony", see 22 Colo. Law. 1185 (1993). For article, "Cross-Examining and Impeaching Expert Psychiatric Witnesses", see 26 Colo. Law. 75 (Nov. 1997).

Cross-examination concerning basis of opinion permitted. It is fundamental that an expert witness may be cross-examined concerning the basis of his opinion. People v. Alward, 654 P.2d 327 (Colo. App. 1982), cert. dismissed, 677 P.2d 948 (Colo. 1984); People v...