Rule 703. Basis of an Expert'S Opinion Testimony

An expert may base an opinion on facts or data in the case that the expert has been made aware of or has personally observed. If experts in the particular field would reasonably rely on those kinds of facts or data in forming an opinion on the subject, the facts or data need not be admissible for the opinion to be admitted.

Committee Notes

Maine Restyling Note [November 2014] Maine Rule of Evidence 703 is similar to its federal counterpart. Maine did not adopt the final subparagraph of Federal Rule 703, an omission that is carried through in the restyled Rule.

Federal Restyling Committee Note The language of Rule 703 has been amended as part of the general restyling of the Evidence Rules to make them more easily understood and to make style and terminology consistent throughout the rules. These changes are intended to be stylistic only. There is no intent to change any result in any ruling on admissibility. The Committee deleted all reference to an "inference" on the grounds that the deletion made the Rule flow better and easier to read, and because any "inference" is covered by the broader term "opinion." Courts have not made substantive decisions on the basis of any distinction between an opinion and an inference. No change in current practice is intended.

Advisers' Note to former M.R. Evid. 703 (February 2, 1976) An expert may base his opinion (1) on firsthand observation, as by a physician treating a patient; (2) on presentation at the trial, as by the familiar hypothetical question or by having the expert attend the trial and hear the testimony establishing the facts relied on; or (3) presentation of data to the expert outside of court and other than by his own direct perception. The key provision is the final sentence allowing opinion on facts or data not admissible in evidence. This is supported by Warren v. Waterville Urban Renewal Authority, 235 A.2d 295 (Me. 1967), although there are earlier cases looking the other way. The plain intention of the rule is to bring judicial practice into line with the practice of experts themselves when not in court. For example, a physician in his own practice bases his diagnosis on information from a variety of sources such as hospital records, X-ray reports, statements by patients, and reports from nurses and technicians. Most of these could be presented in the form of admissible evidence, but only through a timeconsuming process of authentication. The test is whether the facts or data are of a type reasonably relied upon by experts. As the Federal Advisory Committee said: "The physician makes life-and-death decisions in reliance upon them. His validation, expertly performed and subject to crossexamination, ought to suffice for judicial purposes." The question whether facts or data are of a type reasonably relied upon is a preliminary one for the court. A statement by the witness that he, or experts generally, found facts or data of a given type reliable in forming an opinion is not controlling upon the court. The Federal Advisory Committee, to allay the fear that enlargement of permissible data might break down the rules of exclusion unduly, stressed the reasonable reliance requirement and gave the opinion of an "accidentologist" as to the point of impact based on statements of bystanders as an example of a situation where it was not satisfied.