Missouri Legislature passes bill to add expert witness rules

Missouri lawmakers on Wednesday passed legislation to tighten the courtroom guidelines for expert testimony, an effort supporters say is aimed at ensuring experts who testify in court are truly experts.

House members voted 85-68, only three votes more than the threshold needed to pass it, to send the legislation to Gov. Jay Nixon.

Under the proposal, courts would admit expert testimony only after determining it was based on “sufficient facts” and “reliable principles and methods,” as well as being “reliably applied” to the facts of the case. Missouri judges currently admit expert testimony if it’s based on facts “reasonably relied upon by experts in the field.”

Exceptions in the bill include divorce and adoption cases and other cases in juvenile and family court. It also would bar expert witnesses in criminal cases from attributing a defendant’s actions to his or her mental state.

Two of the state’s top business groups say they support changes to expert-witness laws.

“We want to make sure that the jury can rely upon expert testimony,” said Rep. Kevin Corlew, a Kansas City Republican who ushered the bill through the House.

Bipartisan opponents say the measure would make it cost more to get an expert witness and judges would need to vet witnesses’ testimony.

St. Louis Democrat Rep. Mike Colona criticized the measure as part of a push by some Republicans for so-called tort reform.

“Let me translate that for you,” he said on the House floor before the bill passed. “Insurance companies save money, and your constituents lose their rights in court.”