MO SB1309

Amends Section 490.065, RSMo to modify the standard for admitting expert witness testimony in civil jury trial cases in Missouri

Requires the proponent of expert testimony to demonstrate to the court that "it is more likely than not" that the testimony meets reliability requirements, establishing a preponderance of evidence standard for admissibility

Changes language from requiring that "the expert has reliably applied" principles and methods to requiring that "the expert's opinion reflects a reliable application of" those principles and methods to case facts

Maintains separate, less stringent standards for expert testimony in family law cases (chapters 451-455), juvenile court proceedings (chapter 211), family court matters (chapter 487), probate proceedings, and other non-jury trial proceedings

Preserves existing rules allowing property owners to testify about the reasonable market value of their own land regardless of expert qualification requirements