The Gordian Knot of the Treatment of Secondhand Facts Under Federal Rule of Evidence 703 Governing the Admissibility of Expert Opinions: Another Conflict between Logic and Law

University of Denver Criminal Law Review, Forthcoming

UC Davis Legal Studies Research Paper No. 310

33 Pages Posted: 26 Oct 2012 Last revised: 11 Dec 2012

See all articles by Edward J. Imwinkelried

Edward J. Imwinkelried

University of California, Davis - School of Law

Date Written: October 25, 2012


According to some studies, attorneys offer expert testimony at more than 80% of the trials in the United States. When an expert testifies, his or her direct testimony usually has a syllogistic structure: The expert vouches for the validity of a scientific theory or technique (the major premise); the expert then specifies the case-specific data that the theory or technique will be used to evaluate (the minor premise); and the result of the application of the major premise technique to the minor premise data is the expert’s opinion (the conclusion).

In the Supreme Court’s celebrated decision in Daubert v. Merrell Dow Pharmaceuticals, Inc., 509 U.S. 579 (1993), the Court held that Federal Rule of Evidence 702 determines which types of theories and techniques an expert may use as his or her major premise. In Daubert and its progeny, the Court explained that the theory or technique must be supported by enough, methodologically sound empirical reasoning to qualify as reliable “scientific, technical, or...specialized knowledge” under Rule 702.

In contrast, Rule 703 regulates the kinds of data that the expert may factor into his or her minor premise. As at common law, the expert may rely on personally observed facts and facts included in an hypothesis if other witnesses have already presented admissible evidence of all the elements of the hypothesis. However, the innovation in Rule 703 was that it also authorized the expert to rely on out-of-court, secondhand reports that were inadmissible under the hearsay if it was the reasonable, customary practice of specialists in the field to consider such reports. Until recently, the conventional wisdom has been that there was no need for the expert’s proponent to independent, admissible evidence of the facts stated in such secondhand reports. Moreover, the orthodox view was that the judge should instruct the jury that although they could use not use the secondhand reports as substantive evidence, they could consider the reports in evaluating the quality of the expert’s reasoning and the weight of the expert’s opinion.

Earlier this year the Supreme Court handed down its decision in Williams v. Illinois, 132 S.Ct. 221, 183 L.Ed.2d 89 (2012). Williams was a criminal case posing the question of whether a forensic scientist’s reference to another laboratory’s report violated Crawford v. Washington, 514 U.S. 36 (2004). Crawford announced that the Confrontation Clause forbids the introduction of a “testimonial” hearsay statement against an accused unless (1) the accused had a prior opportunity to question the declarant and (2) the declarant is unavailable at trial. However, the Crawford Court indicated that the Confrontation Clause is inapplicable to out-of-court statements used for a nonhearsay purpose at trial.

In Williams, the prosecution argued alternatively that the laboratory report had not been prepared for a testimonial purpose and that the report had not been used at trial for a substantive, hearsay purpose. The prosecution contended that like Rule 703, state law permitted the expert to use the report for a nonhearsay purpose. Five justices (a plurality led by Justice Alito and Justice Thomas concurring) voted to affirm Williams’ conviction on the ground that the report was not testimonial. The plurality did so for the stated reason that the police had not identified a suspect at the time of the laboratory’s test. Justice Thomas also characterized the report as testimonial but on the different ground that the report was informal.

Strictly speaking, the affirmance by that five-justice majority mooted all the other issues in the case. However, between Justice Thomas’ concurrence and Justice Kagan’s dissent, five justices – the 703 majority – expressly rejected the conventional wisdom about Rule 703. Those justices concluded that in order to decide whether to accept an expert opinion, the jury must use the secondhand reports for a substantive, hearsay purpose. Yet neither Justice Thomas nor Justice Kagan discussed the procedural implications of that conclusion.

The purpose of this article is to explore those implications. This article contends that the 703 majority is correct in asserting that it is illogical for the jury to accept the expert’s opinion if an essential premise of the opinion is false. However, the thesis of the article is that although the falsity of an essential premise of an opinion renders the opinion irrelevant, in most cases it is sound to assign the relevance decision to the jury. Analogizing to the conditional relevance procedure codified in Federal Rule 104(b), the article argues that in the typical case it is a satisfactory solution to use of the sort of jury instructions mentioned in Justice Alito’s plurality opinion. As a general proposition, it is unnecessary to empower the judge to decide whether the premises are true and to exclude the opinion if the judge concludes that an essential premise is false.

I do not presume to believe that such a short time after the rendition of Williams I can clearly forecast the ramifications of the 703 majority’s conclusion. However, three things are clear. One is that the 703 majority’s view is a fundamental challenge to the conventional wisdom about Rule 703. The second is that although the 703 majority’s view is not a formal holding in Williams, lower courts are likely to pay attention to the fact that five Supreme Court justices forcefully expressed the view. The third is that while the formal holding in Williams affects only criminal cases, the 703 majority’s view is of interest to any litigator who offers or opposes expert testimony.

Suggested Citation

Imwinkelried, Edward J., The Gordian Knot of the Treatment of Secondhand Facts Under Federal Rule of Evidence 703 Governing the Admissibility of Expert Opinions: Another Conflict between Logic and Law (October 25, 2012). University of Denver Criminal Law Review, Forthcoming, UC Davis Legal Studies Research Paper No. 310, Available at SSRN:

Edward J. Imwinkelried (Contact Author)

University of California, Davis - School of Law ( email )

Martin Luther King, Jr. Hall
Davis, CA CA 95616-5201
United States

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