Colo. R. Evid. 703
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 in order for the opinion or inference to be admitted. Facts or data that are otherwise inadmissible shall not be disclosed to the jury by the proponent of the opinion or inference unless the court determines that their probative value in assisting the jury to evaluate the expert's opinion substantially outweighs their prejudicial effect.
(Federal Rule Identical.)
CRE 703
Committee Comment
The Committee believes this rule is a substantial deviation from former Colorado law, but there are former cases lending partial support to the rule. See: Hensel Phelps Construction Co. v. U.S., 413 F.2d 701 10th Cir. (1969); Houser v. Eckhardt, 168 Colo. 226, 450 P.2d 664 (1969); McNelley v. Smith, 149 Colo. 177, 368 P.2d 555 (1962); Ison v. Stewart, 105 Colo. 55, 94 P.2d 701 (1939); Enyart v. Orr, 78 Colo. 6, 238 P. 29 (1925); Rio Grande W. Ry. Co. v. Rubenstein, 5 Colo. App. 121, 38 P. 76 (1894). See also, Good v. A.B. Chance Co., 39 Colo. App. 70, 565 P.2d 217 (1977). Although not directly in point, we believe the case supports the last sentence of Rule 703. (Amended March 5, 1981, effective July 1, 1981.)
Annotation Law reviews. For article, "Admissibility of Governmental Studies to Prove Causation", see 11 Colo. Law. 1822 (1982). For article, "Hearsay as a Basis for Opinion Testimony", see 17 Colo. Law. 2337 (1988). "Opinion Testimony", see 22 Colo. Law. 1185 (1993). For article, "Tips for Working With Evidence in Domestic Relations Cases", see 31 Colo. Law. 87 (June 2002). Fact that expert witness has not examined accused does not necessarily disqualify him from expressing his opinion based upon a hypothetical question, but such an opinion must be based on facts in evidence. People v. Manier, 184 Colo. 44, 518 P.2d 811 (1974). Neither collegiate degrees nor formal training in an established curriculum is necessarily required before one may be considered an expert in a particular field. People v. Genrich, 928 P.2d 799 (Colo. App. 1996). Expert's opinion may not be predicated on others' opinions. An expert's opinion must not be predicated, in whole or in part, on opinions of others, expert or lay. People v. Beasley, 43 Colo. App. 488, 608 P.2d 835 (1979); People v. District Court, 647 P.2d 1206 (Colo. 1982). Nor on facts varying from actual facts. An expert opinion buttressed by assumed facts at variance with the actual facts has no evidential efficacy. High v. Indus. Comm'n, 638 P.2d 818 (Colo. App. 1981). Opinion based on information gained through hypnosis inadmissible. A psychiatrist will not be permitted to testify as to the mental state of the defendant if his opinion is based on information gained through hypnosis. People v. Diaz, 644 P.2d 71 (Colo. App. 1981). Expert witness may be cross-examined. 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). By learned treatises. Expert may be cross-examined using learned treatises even though he did not rely upon them in reaching his conclusions. People v. Beasley, 43 Colo. App. 488, 608 P.2d 835 (1979). Competence to testify as to medical standards. Generally, practitioners of one school of medicine are not competent to testify as experts relative to standards of care required of practitioners of another school. Greene v. Thomas, 662 P.2d 491 (Colo. App. 1982). However, a physician from one specialty may testify concerning the standard of care required of a physician with a different specialty, provided that the expert witness has acquired, through experience or study, more than just a casual familiarity with the standards of care of the defendant's specialty. Greene v. Thomas, 662 P.2d 491 (Colo. App. 1982). Opinion may be based on facts or data not admissible in evidence. Graefe & Graefe v. Beaver Mesa Exploration, 695 P.2d 767 (Colo. App. 1984). But this rule does not permit otherwise inadmissible facts or data contained in a report or statement to be admitted merely because the expert relied on them. Leiting v. Mutha, 58 P.3d 1049 (Colo. App. 2002). Expert's testimony itself is inadmissible when underlying basis for the expert opinions and recommendations is not accepted as reliable by the courts. Because of the lack of a scientific basis and reliability, it is inappropriate for an expert witness to rely on polygraph results to form or render an opinion. Trial court should not have listened to, or considered, the opinions of any experts based, in whole or in part, on polygraph examinations. People ex rel. M.M., 215 P.3d 1237 (Colo. App. 2009). Interpretation of blood test results by expert whose qualifications are established in field of blood type testing was admissible evidence. K.H.R. By and Through D.S.J. v. R.L.S., 807 P.2d 1201 (Colo. App. 1990). It is permissible for an expert to rely on data which itself may be inadmissible. People v. Diefenderfer, 784 P.2d 741 (Colo. 1989). Expert's opinion may be based upon other reliable expert opinions due to the adoption of this rule. Gold Rush Inv. v. G.E. Johnson Const., 807 P.2d 1169 (Colo. App. 1990). Court did not err in admitting expert testimony of licensed physician whose opinion was based in part upon information received from psychiatrist in residency together with the physician's own examination of hospital records, charts, hospital admission data, and his own observations of respondent. People in Interest of Martinez, 841 P.2d 383 (Colo. App. 1992). Admission of expert testimony was not abuse of trial court's discretion, where expert based his opinion on data contained in microscope slides and reports prepared by two other doctors since that opinion was based upon an opinion of a type reasonably relied upon by experts in the particular field in forming opinions or inferences upon the subject. Fenton v. Fibreboard Corp., 827 P.2d 564 (Colo. App. 1991). Trial court did not abuse its discretion in allowing pediatrician to testify that rib fractures were a basis for the pediatrician's conclusion that child died as a result of shaken baby syndrome. People v. Cauley, 32 P.3d 602 (Colo. App. 2001). An expert may express an opinion based upon assumptions that have a reasonable basis in the evidence so long as the information is of the type reasonably relied upon by experts in the field of expertise. Vento v. Colo. Nat'l Bank-Pueblo, 907 P.2d 642 (Colo. App. 1995). Reliance upon facts not personally observed but which have been reasonably relied upon by experts in the same field is an acceptable basis of expert opinion and the trial court has broad discretion in determining whether the requirements governing expert opinions have been satisfied and whether the expert's testimony is admissible. Gold Rush Investments, Inc. v. Johnson, 807 P.2d 1169 (Colo. App. 1990); Fenton v. Fibreboard Corp., 827 P.2d 564 (Colo. App. 1991). An expert is not required on direct examination to disclose the underlying facts that form the basis for his or her opinion, however, nothing prevents an expert from doing so, and it was proper for expert in case at hand to give his opinion on how defendant's drawings and narratives related to a sexual homicide. People v. Masters, 33 P.3d 1191 (Colo. App. 2001), aff'd on other grounds, 59 P.3d 979 (Colo. 2002). The weight to be accorded to the property valuation techniques of an expert in a marriage dissolution is for the trial court's determination, depending upon the court's assessment of the reliability of the data in a particular case. In re Bookout, 833 P.2d 800 (Colo. App. 1991), cert. denied, 846 P.2d 189 (Colo. 1993). The weight to be accorded to the valuation techniques of an expert is for the trial court to determine depending upon the court's assessment of the reliability of the data in a particular case. In re Bookout, 833 P.2d 800 (Colo. App. 1991), cert. denied, 846 P.2d 189 (Colo. 1993). Certainty goes to weight, not admissibility. Once a witness is qualified as an expert, the fact that the examination reveals that he or she cannot support the opinion with certainty goes only to the weight to be given the opinion and not its admissibility. Vento v. Colo. Nat'l Bank-Pueblo, 907 P.2d 642 (Colo. App. 1995). Applied in Stone v. Caroselli, 653 P.2d 754 (Colo. App. 1982); People v. Williams, 654 P.2d 319 (Colo. App. 1982); Jimerson v. Prendergast, 697 P.2d 804 (Colo. App. 1985).