MICHAEL D. MARCUS’S MEDIATION MESSAGE NO. 124
EXPERT TESTIMONY AND THE HEARSAY RULE:
GENERALIZED BACKGROUND INFORMATION VERSUS CASE-SPECIFIC FACTS
In People v. Sanchez (2016) 63 Cal.4th 665, a unanimous Supreme Court clarified what information and facts experts rely upon are and are not subject to a hearsay objection. Sanchez holds the hearsay rule applies to case-specific out-of-court statements considered by experts as true and accurate and relied upon to support their opinions, because such statements are being admitted for the truth. (Id. at p. 686.) “Case-specific facts are those relating to the particular events and participants alleged to have been involved in the case being tried.” (Id. at p. 676.) (Note: Although Sanchez is a criminal case, its holding applies to both criminal and civil cases. In criminal cases, expert testimony must also satisfy the Sixth Amendment’s Confrontation Clause.)
Sanchez found it necessary to draw a clear distinction between expert reliance on background information and case-specific facts because the courts had been using a limiting instruction that “matters admitted through an expert go only to the basis of his opinion and should not be considered for their truth.” “(U)nder this paradigm, there was no longer a need to carefully distinguish between an expert’s testimony regarding background information and case-specific facts. The inquiry instead turned on whether the jury could properly follow the court’s limiting instruction in light of the nature and amount of the out-of-court statements admitted.” However, “this paradigm was no longer tenable because an expert’s testimony regarding the basis for an opinion must be considered for its truth by the jury.” (Id. at p. 679; emphasis in the original.) Thus, case-specific out-of-court statements “must be properly admitted through an applicable hearsay exception” or, alternatively, “through an appropriate witness and the expert may assume its truth in a properly worded hypothetical question in the traditional manner.” (Id. at p. 684.)
Under Sanchez, experts may continue to rely upon background information, which is not subject to a hearsay objection. “Our decision does not call into question the propriety of an expert’s testimony concerning background information regarding his knowledge and expertise and premises generally accepted in his field. Indeed, an expert’s background knowledge and experience is what distinguishes him from a lay witness, and, as noted, testimony relating such background information has never been subject to exclusion as hearsay, even though offered for its truth. Thus, our decision does not affect the traditional latitude granted to experts to describe background information and knowledge in the area of his expertise. Our conclusion restores the traditional distinction between an expert’s testimony regarding background information and case-specific facts.” (Id. at p. 685.)
MDM’s observation: If a party asks an expert about hypothetical facts which have not yet been established by another witness, the opponent should object to that hypothetical because the underlying facts have not been established. In response, the proponent of the evidence should ask for permission to ask the hypothetical question out of order, subject to establishing later on the foundation for its admissibility. If the objection is overruled (as it probably will be), the opponent should later reassert the objection and move to strike the applicable testimony (or even move for a mistrial depending on the significance of the expert’s opinion) if the background facts for the hypothetical were not established.
Judge Michael D. Marcus (Ret.)
ADR Services, Inc.
1900 Avenue of the Stars, Suite 250
Los Angeles, California 90067
Copyright Michael D. Marcus, August 2016