Trial courts have substantial discretion when deciding whether to admit evidence at trial. This discretion extends to expert witness testimony. On appeal, a trial court’s decision to admit or exclude expert testimony is reviewed for an abuse of discretion. Spalding v. Stewart Title Guar Co., 463 S.W.3d 770, 778 (Mo. 2015).
Not everything is discretionary. There are some more black and white requirements. Specifically, expert witness testimony is inadmissible if the offering party fails to satisfy the expert witness statute’s foundational requirements. Scott v. Blue Spring Ford, Inc., 215 S.W.3d 145, 173 (Mo. Ct. App. 2006). Once expert witness testimony is properly admitted, though, the weight to give that testimony is up to the judge/jury deciding the case.