Rule 703 Bases of Opinion Testimony by Experts

• Jurisdiction: Arizona

The facts or data in the particular case upon which an expert bases an opinion or inference may be those perceived by or made known to the expert at or before the hearing. If of a type reasonably relied upon by experts in the particular field in forming opinions or inferences upon the subject, the facts or data need not be admissible in evidence.

Comment

This rule allows an expert to give an opinion based on any one or any combination of the following: (1) evidence presented at the trial;[1] (2) hypothetical questions based upon either evidence presented at trial or facts and data not presented at trial;[2] (3) the expert's own firsthand observations; and (4) facts or data given to the expert outside of court from other than the expert's own perception.[3] If the facts or data have not been admitted in evidence, the expert may base an opinion on them only if they are of a type upon which experts in that particular field reasonably rely in forming their opinions or inferences.[4] Further, an expert may base an opinion on statements the trial court has suppressed as long as the statements are of a type upon which experts in that particular field reasonably rely.[5] It is the duty of the trial court to determine, under Rule 104(a), whether the facts or data are of the type upon which experts reasonably rely.

If the facts or data have not been admitted in evidence but are of a type upon which experts reasonably rely, they may be disclosed under Rule 705 either on direct or on cross-examination,[6] but only for the limited purpose of showing the basis for the opinion, and are not to be considered as substantive evidence by the trier-of-fact.[7] Although this rule allows disclosure of facts not admitted in evidence, it does not allow disclosure of the facts if a constitutional provision, statute, or rule specifically precludes their admission.[8] Because this rule allows for the disclosure of otherwise inadmissible evidence, the trial court should exercise caution in its use so that it is not used merely as a guise to introduce otherwise inadmissible evidence.[9] For example, if an expert witness relies upon facts or data contained in a report not admitted in evidence, the trial court should allow the witness to disclose the facts or data, but should not admit the report itself because the report would still be hearsay. If the trial court admits such facts or data, a party would be entitled to an instruction under Rule 105 that the evidence is admitted only to show the basis for the opinion and not as substantive evidence.

Cases

703.010 Expert opinion may be based on objects admitted in evidence and matters not admitted in evidence.

State v. Villafuerte,142 Ariz. 323, 690 P.2d 42 (1984) (medical examiner allowed to testify about results of laboratory reports not prepared by him).

State v. Noleen,142 Ariz. 101, 688 P.2d 993 (1984) (medical examiner allowed to testify about autopsy based on reports of autopsy conducted by another medical examiner).

State v. Williams,132 Ariz. 153, 644 P.2d 889 (1982) (expert opinion on ultimate issue that sharpened stick was dangerous admissible when expert viewed stick and police officers' protective gear, even though expert did not hear all testimony at trial).

Mohave Elec. Coop. v. Byers,189 Ariz. 292, 942 P.2d 451 (Ct. App. 1997) (in ruling on motion for summary judgment, trial court could consider audit report upon which expert relied).

State v. Curry,187 Ariz. 623, 931 P.2d 1133 (Ct. App. 1996) (one expert witness permitted to give opinion based in part on child sexual abuse accommodation syndrome research done by another; another expert witness permitted give opinion about victim based on personal examination of victim done by another doctor).

Gaston v. Hunter,121 Ariz. 33, 588 P.2d 326 (Ct. App. 1978) (medical expert may testify to effect of drug without having personally prescribed it himself).

Rayner v. Stauffer Chem. Co.,120 Ariz. 328, 585 P.2d 1240 (Ct. App. 1978) (expert may render opinions based on photographs in evidence).

703.020 Expert opinion may be based on learned articles or treatises.

Gaston v. Hunter,121 Ariz. 33, 588 P.2d 326 (Ct. App. 1978) (erroneous exclusion of expert opinion based upon learned medical articles resulted in reversal of judgment in favor of defendant and remand for a new trial).

703.030 An accurate factual basis is a necessary element of a legally sufficient opinion.

State v. Miles,186 Ariz. 10, 918 P.2d 1028 (1996) (because psychologist testified he did not know how often and in what quantities defendant had used cocaine before murder, psychologist had no basis upon which to render an opinion about effects of cocaine on defendant at time of murder).

Florez v. Sargent,185 Ariz. 521, 917 P.2d 250 (1996) (because affidavits contained only conclusions that plaintiffs were of unsound mind and did not contain any facts to support those conclusions, affidavits did not raise a question of fact, thus trial court should have granted defendants' motion for summary judgment).

Standard Chartered PLC v. Price Waterhouse,190 Ariz. 6, 945 P.2d 317 (Ct. App. 1996) (in litigation over sale of bank, plaintiff-purchaser claimed that $23 million loss reserve figure supplied by defendant-seller understated amount of uncollectable loans; defendant-seller sought to introduce tax filing made by plaintiff-purchaser 1½ years after sale showing a loss reserve of $9.8 million; trial court excluded this evidence because defendant-seller's expert witness could not testify to what plaintiff-purchaser actually did in preparing tax filing and could only testify about what plaintiff-purchaser should have done; court held that there was sufficient factual basis for the evidence and thus it should have been admitted, and that any dispute about the $9.8 million figure went to weight and not admissibility of the opinion).

Bledsoe v. Salt River Valley Water Users,179 Ariz. 469, 880 P.2d 689 (Ct. App. 1994)...