In today’s Johnston-Forbes v. Matsunaga decision, the Washington Supreme Court reiterated the rule that expert testimony is admissible if (1) the expert is qualified, (2) the expert relies on theories that are generally accepted in the scientific community, and (3) the testimony would be helpful to the trier of fact. The trial court has to determine on a case-by-case basis whether the three requirements have been met. It is afforded wide discretion in making that determination. That wide discretion is the reason the Court considered it “not remarkable” that some trial courts have allowed a professor in biomechanical engineering to testify about the forces exchanged in a car collision and compare those forces to activities in daily living, while other trial courts have excluded testimony by the same expert.

It also is worth noting that the Court refused to consider the appellant’s challenge to whether the expert’s methods are generally accepted by the scientific community. Because the appellant had not challenged the proposed testimony on that ground in the trial court, nor had she requested a Frye hearing, both the Court and the Court of Appeals refused to consider that issue.