Practitioners who try cases in both Federal District courts and California state courts are all too aware of the schism that has existed between the courts for almost two decades on the question of admissibility of expert opinion. California has long adhered to a line of authorities tracing back to 1923, when Frye v. United States (293 F. 1013 (D.C. Cir.)) was decided. The Frye test, also known as the “general acceptance” test held that a new scientific technique or methodology was inadmissible unless and until the proponent of the evidence established that the technique or methodology had attained “general acceptance” in the relevant field. The California Supreme Court adopted the Frye test in 1976. (People v. Kelly, 17 Cal.3d 24, 32.)
Since the 1993 decision of Daubert v. Merrell Dow Pharmaceuticals, Inc. (509 U.S. 579), federal courts have applied a different standard. Under the Daubert rule, the trial court’s role is to act as a “gatekeeper” to ensure expert testimony that is admitted is reliable based on certain factors, including whether the opinion was being developed solely for purposes of litigation, whether the opinion or methodology had been independently tested in the scientific community and the potential for error.
The schism between federal and California courts continued until the California Supreme Court’s recent pronouncement, in Sargon Enterprises, that “the trial court has the duty to act as a gatekeeper to exclude speculative expert testimony.” The evidence at issue in Sargon was proposed testimony of a damages expert on lost profits suffered by a dental implant inventor who claimed the University of Southern California School of Dentistry had botched a clinical trial of its invention. In holding that the trial court had properly excluded the lost profits opinions, the California Supreme Court said:
“Under [California] Evidence Code section 801, the trial court acts as a gatekeeper to exclude speculative or irrelevant expert opinion. As we recently explained, [t]he expert’s opinion may not be based on ‘assumptions of fact without evidence support, or on speculative or conjectural matters . . . Exclusion of expert opinions that rest on guess, surmise or conjecture is an inherent corollary to the foundational predicate for admission of the expert testimony: will the testimony assist the trier of fact to evaluate the issues it must decide?”
The California Supreme Court did caution trial courts, however, that their analysis must focus on methodology, not on conclusions. It said: “The trial court’s gatekeeping role does not involve choosing between competing expert opinions.” Referring to the U.S. Supreme Court’s opinion in Daubert, it said, “The high court warned that the gatekeeper’s focus must be solely on principles and methodology, not on the conclusions that they generate.”