MO SB975

Repeals and replaces section 490.065, RSMo, establishing new standards for expert witness testimony in civil actions.

Expert witnesses may testify if their knowledge will help the trier of fact understand evidence or determine facts in issue, and the testimony is based on sufficient facts, reliable principles and methods, and reliable application of those principles to the case facts.

Expert opinions may be based on facts or data that experts in the field would reasonably rely upon, even if those facts or data would otherwise be inadmissible, unless their prejudicial effect substantially outweighs their probative value.

Expert opinions on ultimate issues are generally admissible, except in criminal cases where experts cannot opine on whether a defendant had the mental state or condition constituting an element of the charged crime or defense.

Experts may state opinions and provide reasons without first testifying to underlying facts or data, but may be required to disclose those facts or data on cross-examination.