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California Courts Move Closer to Federal Standard for Admissibility of Expert Testimony

California Evidence Code section 801 is of growing importance to defense counsel working to exclude junk science from trial. The reach of the longstanding "Kelly test" — which had been the strongest legal authority against unfounded expert opinion testimony — has recently been limited to "novel scientific techniques," and the substance of an expert's opinion is not subject to scrutiny under Kelly. On the other hand, the prerequisites established by Evidence Code section 801 have been read broadly to prohibit opinion testimony based on matters not reasonably relied upon by other experts, or upon factors that are "speculative, remote or conjectural" regardless of whether the techniques relied upon in forming that opinion are well-accepted (In re Lockheed Litigation Cases (JCCP 2967) (2nd Dist. 2004) 115 Cal.App.4th 558, 563.). The Lockheed rule allows the trial judge to determine whether the substance of an expert's opinion is reasonable given the matter relied upon.

In 2003, the appellate courts held that the Kelly test applies "only to new scientific techniques" and not the personal opinions and conclusions drawn by experts (no matter how unreasonable) who rely on accepted methodologies ( Roberti v. Andy's Termite and Pest Control (2nd Dist. 2003) 113 Cal.App.4th 893, 900 (citing People v. Mitchell (2003) 110 Cal.App.4th 772). Furthermore, expert medical opinions "based entirely upon generally accepted diagnostic methods and tests, including statistical studies that are not definitive" are immune from attack under the Kelly test. (Id.)

In 2004, the California appellate court gave defendants an alternative to the former Kelly test. In the Lockheed litigation cases the court ruled that the statistical study relied upon by the plaintiffs' expert as well as the conclusions he drew therefrom could be scrutinized pursuant to Evidence Code section 801. The court found that the study was not definitive, thus the expert's opinion was speculative and inadmissible.

The plaintiffs sought to introduce Dr. Teitelbaum's opinion that plaintiffs' exposure to five chemicals supplied by Union Oil and Exxon Mobil to Lockheed's "Skunk Works" facility in Burbank, California (where the F117 Stealth Fighter was built), caused them injury. Dr. Teitelbaum relied exclusively upon an epidemiological study that found that persons exposed to 130 chemicals together, including the five at issue in Lockheed, were more likely to develop cancer. The trial court found that it was unreasonable to assume that the five chemicals at issue in the case were responsible when many of the remaining 125 were known carcinogens. As such, Dr. Teitelbaum's opinion was speculative and conjectural so the trial court excluded it and sustained defendant's motion for summary judgment.

Evidence Code section 801 provides that an expert opinion must be "[b]ased on matter (including his special knowledge, skill, experience, training, and education) perceived by or personally known to the witness or made known to him at or before the hearing, whether or not admissible, that is of a type that reasonably may be relied upon by an expert in forming an opinion upon the subject to which his testimony relates ...." (Evid. Code § 801(b) (emphasis added)). The Lockheed court construed the language "upon the subject to which his testimony relates" to mean that the matter relied upon must provide a reasonable basis for the particular opinion offered and that speculation or conjecture is inadmissible. (Lockheed, 115 Cal.App.4th at 564.)

The value of opinion evidence rests not in the conclusion reached but in the factors considered and the reasoning employed. [Citations.] When an expert bases his conclusion upon assumptions that are not supported by the record, upon matters that are not reasonably relied upon by other experts, or upon factors that are speculative, remove or conjectural, then his conclusion has no evidentiary value.

(Lockheed, 115 Cal.App.4th at 563.)

The plaintiffs argued that analysis under the Evidence Code is limited to the question of whether the matter relied upon is of the type relied upon by experts in the field. This argument had proved successful for plaintiffs under the Kelly rule, see Roberti above, but Lockheed held that the Evidence Code authorizes a court to consider whether the specific assertions made are reasonably supported by valid research, based on section 801 cited above, and based on the general principal that "an expert opinion has no value if its basis is unsound." (People v. Lawley (2002) 27 Cal.4th 102, 132.)

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