Modifies provisions relating to the admissibility of expert testimony evidence

SB 1309 modifies rules for admitting expert testimony in court. It requires experts to base opinions on reliable data and methods, and mandates that testimony must help the judge or jury understand evidence or resolve facts. The bill applies to most civil cases (like family law or probate) and criminal cases, but specifically prohibits experts from stating opinions about a defendant’s mental state in criminal trials. These changes aim to ensure expert testimony is both relevant and scientifically sound before being presented to a court.