States legislatures, bar associations, and courts are continuing to debate the appropriate standard for the admission of expert testimony. As an attempt to defeat the Florida legislature’s adoption of the Daubert standard heats up, the Missouri legislature has sent Governor Jay Nixon a bill that would replace the state’s current rule of expert testimony admissibility with a Daubert standard.

The Daubert standard

Having been adopted by the federal government and a majority of states, the Daubert standard is now familiar to lawyers and to expert witnesses. Judges applying Daubert generally see their role as that of a “gatekeeper.” Before allowing a jury to hear expert testimony, the judge must be satisfied that the expert’s testimony is both relevant and reliable.

Expert testimony is relevant under Daubert if it would help the jury decide the case and if:

• the testimony is based on sufficient facts or data;
• the testimony is the product of reliable principles and methods; and
• the expert has reliably applied the principles and methods to the facts of the case.

To decide whether scientific principles and methods are reliable, Daubert requires the judge to consider whether the method that the expert used to form a scientific opinion:

• can be and has been tested;
• has been subjected to peer review and publication;
• is not associated with an unacceptable error rate;
• is controlled by standards; and
• has attracted widespread acceptance within a relevant scientific community.

More ambiguous standards govern the evaluation of nonscientific expert testimony, which by its nature does depend upon the application of the scientific method.

The Missouri Bill

The bill that passed the Missouri House would adopt the Daubert standard in most trials. The current Missouri rule of expert evidence provides that an expert may testify in the form of an opinion if the opinion would help the jury (or the judge in a bench trial) “understand the evidence” or “determine a fact in issue,” provided the expert is “qualified as an expert by knowledge, skill, experience, training, or education.” To form an opinion, the expert may rely on any “reasonably reliable” facts that are “of a type reasonably relied upon by experts in the field.”

Like the Daubert standard, the current Missouri rule does not require experts to form opinions by using a methodology that has gained widespread acceptance. The Missouri rule therefore differs from the traditional Frye standard of admissibility. “Widespread acceptance” is a factor the court can consider under Daubert, but no single factor is controlling.

At the same time, the Missouri rule differs from Daubert, which does not require experts to rely on the kind of facts that would ordinarily be relied upon by other experts in the same field. In that sense, Missouri’s current rule might be more restrictive than the Daubert standard. It is therefore unclear whether the change proposed by the bill would benefit plaintiffs or defendants.

As a general rule, lawyers who represent businesses and insurance companies like Daubert because they believe it gives them an opportunity to prevent plaintiffs’ experts from testifying when their opinions are not based on customary or orthodox methodologies. Plaintiff’s lawyers and consumer advocates tend to view Daubert as improperly substituting the judge’s opinion for the jury’s in the assessment of a methodology’s reliability.

Daubert’s Unclear Impact

In reality, the distinction between the Daubert standard, the Frye standard, and the current Missouri standard is only important at the fringes, since most scientific experts based their opinions on uncontroversial methodologies, even when their opinions conflict. One study suggests that the difference between standards of expert opinion admissibility does not typically affect the outcome of a case. The Missouri Bar’s Expert Witness Legislation Working Group concluded that there is no objective proof that the Frye standard, the Daubert standard, or the current Missouri standard is more likely to increase the fairness of a trial, although the Daubert standard tends to impose greater burdens on the judicial system by making more work for judges.

The Missouri bill would apply the Daubert standard to civil cases other than those arising in probate court, juvenile court, or family court. If the true purpose of the bill is to increase the reliability of evidence, it seems odd that the Missouri legislature would think that juvenile and family cases should turn on less reliable expert evidence.

The bill’s fate is now in the hands of Governor Nixon. The bill was supported by business lobbyists but opposed by the state’s Circuit Judges Association and a bipartisan group of legislators. The Missouri Times reports that the governor is expected to veto the bill.