Yesterday, March 28, 2017, Missouri Governor, Eric Greitens, signed House Bill 153. This Bill amends parts of section 490.065 of the Missouri Revised Statutes (RSMo), which governs testimony of expert witness.

With the enactment of the new standards under 490.065(2), Missouri’s approach to expert testimony now aligns with that of the Federal Courts. The requirements as set out Subsection Two are identical to those of Federal Rules of Evidence 702, 703 and 705, which are the basis for the principles of the Daubert Standard as set out by the United States Supreme Court. See Daubert v. Merrell Dow Pharmaceutical, 509 U.S. 579 (1993). This consistency between Missouri and Federal Court standards is significant because it should make it easier to exclude unscientific “junk science.”

Subsection Two applies to majority of civil actions in Missouri state courts. Thus, this section will likely be more relevant to litigators engaged in general civil practice.

Under this subsection, an expert may testify in the form of an opinion or otherwise if:

  • the expert’s specialized knowledge will assist the trier of fact to understand evidence or determine a fact in issue;
  • the expert’s testimony is based on sufficient facts or data;
  • the testimony is the product of reliable principles and methods; and
  • the expert has applied those reliable principles and methods in the case at hand.

Further, an expert may base his opinion on facts or data that expert has been made aware of or personally observed. These facts or opinions need not be admissible to be admitted if the experts in that field would reasonably rely on those kinds of facts or data in forming an opinion. However, if the facts would otherwise be inadmissible, the proponent of the opinion may disclose them to the jury only if their probative value outweighs their prejudicial effect.

Generally, an expert opinion is not objectionable simply because it embraces the ultimate issues; however, in a criminal case an expert absolutely cannot state an opinion about whether the defendant did or did not possess the necessary mental state.

Finally, an expert may state an opinion and give reasons for that opinion without first testifying to underlying facts or data, unless the court orders otherwise. However, the expert may be required to disclose those facts or data on cross-examination.