MO HB697

Amends section 490.065, RSMo to create a two-tiered standard for expert witness testimony in Missouri civil cases

Family law cases (chapters 451-455), juvenile court cases (chapter 211), and family court cases (chapter 487) retain the existing, more permissive standard allowing expert testimony if it will assist the trier of fact

All other civil actions must meet stricter requirements: expert testimony must be based on sufficient facts or data, use reliable principles and methods, and the expert must have reliably applied those methods to the case facts (similar to the federal Daubert standard)

In criminal cases, expert witnesses are prohibited from stating opinions about whether the defendant had the mental state required for the crime or defense—that determination is reserved for the trier of fact alone

Experts may state opinions without first testifying to underlying facts, but may be required to disclose those facts during cross-examination