In California, nearly every type of civil litigation involves the use of expert witnesses and their testimony. However, the trial judge, as gatekeeper, can and often does preclude certain expert testimony from being considered evidence in a case. The clear dilemma for legal practitioners and litigants is to ensure that the expert testimony they utilize will not be excluded but will, instead, be considered reliable and persuasive to judges and juries.
California expert witnesses and litigators need to be aware of the California Evidence Code. According to the California Evidence Code, expert witnesses can testify about issues “of a type that reasonably may be relied upon by an expert in forming an opinion upon the subject to which his testimony relates.” Upon objection, a trial court is by the California Code to “exclude testimony in the form of an opinion that is based in whole or in significant part on matter that is not a proper basis for such an opinion.” Cal. Evid. Code §801, 803.
In recent product liability litigation, a California court granted the defendant summary judgment, on the grounds that the plaintiff’s witness only used certain studies in his testimony, which did not scientifically or logically establish legal causation and thus, liability on the defendant’s part. See Lockheed Litigation Cases (115 Cal. App. 4th 558 (2004) (Lockheed I); Lockheed Litigation Cases, 126 Cal. App. 4th 271 at 285 (2005) (Lockheed II); In re Lockheed Litig. Cases, 83 Cal. Rptr. 3d 478 (2007).
The bottom line, according to the California courts, is that expert testimony should not be accepted, merely because the person testifying has expertise. The expert has to be testifying about his or her particular methodology used, and those methods have to be considered logical, reliable, and realistic. More importantly, the standards used by an expert witness should be well-accepted within the field about which he or she is giving testimony.
Courts will reward expert witnesses who lay a basic foundation for their conclusions and premises. They are looking for strong indications and tests from experts that prove that a certain act did or did not most likely contribute to a specific set of consequences. As the burden of proof in civil cases is “a preponderance of evidence,” or, in lay terms, 51%, experts testifying before California courts face a similar test: For a court to accept their testimony, experts need to lay a foundation that indicates that it can be reasonably and logically deduced that a certain act was or was not responsible for a certain ensuing set of events.
As one California court has indicated, the California Evidence Code simply requires expert witnesses to know what they are testifying about. Or, to quote Lockheed, an expert’s testimony must be “sufficient to establish to a reasonable…probability”—that is, “more than a mere possibility” that one party’s acts caused or contributed to the other party’s injuries or damages. Lockheed II, 126 Cal. App. 4th, at 287.
To make sure that, as a litigant or attorney, your expert testimony is included in California civil litigation, the Lockheed cases offer some basic guidance to understanding, interpreting, and getting the appropriate experts to meet the standards of the California Evidence Code. Trial courts are still the gatekeepers and can still exclude testimony, if they believe a proper foundation for the evidence has not been established.
When California courts decide upon the admissibility of expert testimony, the general trend seems to favor relying on more than one type of study or upon a consensus that pertains to the specific field upon which an expert testifies, and providing a clear link between the issue the expert is testifying about and the conclusion being drawn. Finally, as one California court put it, “Like a house built on sand, the expert’s opinion is no better than the facts on which it is based.” Kennemur v. St. of Cal., 133 Cal. App. 3d 907, 923 (1982). If the recommended steps are followed, courts in California are more likely to admit expert testimony, ruling it not merely conjecture but reliable evidence based on sound, scientific principles.
By: Kat Hatziavramidis, Attorney-at-Law