Senate Bill 459 amends the existing statute regarding the admissibility of expert witness testimony in Wisconsin to align with recent updates to the Federal Rule of Evidence (FRE) 702. The bill specifies that an expert witness may testify if their scientific, technical, or specialized knowledge assists the trier of fact in understanding the evidence or determining a fact at issue. It introduces a requirement for the proponent of the testimony to demonstrate to the court that it is more likely than not that the testimony is based on sufficient facts or data, is the product of reliable principles and methods, and that the witness's opinion reflects a reliable application of those principles and methods to the case's facts.

The bill modifies the language of the statute by inserting the requirement for the proponent to demonstrate the reliability of the testimony and removing the phrase that the witness has applied the principles and methods reliably. This change emphasizes the court's gatekeeping role in evaluating expert testimony, ensuring that only reliable and relevant expert opinions are presented in court. The new provisions will apply to actions or special proceedings commenced on the effective date of the bill.

Statutes affected:
Bill Text: 907.02(1), 907.02