Changes in Expert Witness Rules Expected in Coming Legislative Session

By Rebecca Close, Law Clerk for Bollwerk & Tatlow, LLC and 3-L, St. Louis University School of Law


With a new legislative session beginning soon, there is heavy discussion about changes in Missouri law that could impact the testimony of expert witnesses in civil cases.

Currently, there are 47 states that follow one of two common standards for allowing someone to qualify as an expert witness.  The Frye standard, followed in 8 states, requires only that the technology or method used by the expert be generally accepted in the relevant expert community.  The more popular standard, used in 39 states and in federal courts, is the Daubert standard.  Under this standard, qualifying an expert witness requires a judge to evaluate the expert’s method or technique under the following criteria:


1.     Whether the method can be and has been tested;

2.     Whether it has been subjected to peer review and publication;

3.     It’s known or potential error rate;

4.     Whether maintenance standards exist to control its operation;

5.     Whether it has widespread acceptance within the relevant scientific community.


Missouri’s standard is currently governed by statute and falls somewhere between these two standards.  Under the statute, the presiding judge weighs the expert’s knowledge, skill, experience, training and education, and whether the expert’s opinion is “reasonably reliable.”  Like the Frye standard, Missouri requires acceptance by other experts in the field, but like the Daubert standard, Missouri also requires consideration of additional criteria and that the expert’s method be reasonably applied to the facts of the case in which the expert is testifying.

In April 2016, the Missouri legislature passed a bill to move Missouri to the Daubert standard.  The bill was vetoed by Governor Nixon in June 2016.  However, with a new legislative session about to begin and governor-elect Eric Greitens taking office, it’s likely we will see this issue rise again.

So what does this mean for injured plaintiffs?

Well, proponents of the Daubert standard argue that Missouri judges would have more clarity in weighing the credibility of expert witnesses by offering specific criteria to consider.  Opponents, on the other hand, believe the Daubert standard would only burden the state judicial system further by requiring state judges to qualify experts under these specific criteria instead of simply making their own credibility determinations. 

Proponents also argue that the Daubert standard protects against verdicts that are based on “junk science” and will improve the quality of expert testimony.   However, those opposed to the standard say this is simply not true because the judge already plays a crucial role in determining the credibility of expert testimony under Missouri’s current law.  If the judge does not find the expert’s methods credible, the expert will not be allowed to testify. 

Opponents believe that implementing this new standard only serves to make identifying, retaining and qualifying someone as an expert witness much more costly for injured plaintiffs who often have fewer resources than “big business” defendants when litigating their claims in the first place.  Operating under a Daubert standard would only create one more hurdle in the already uphill battle for an injured plaintiff. 


Be the first to comment!
Post a Comment