Jury instructions regarding expert witnesses in Missouri are not outlined in Missouri’s jury instructions. Instead, case law provides a basis for how the jury should be instructed regarding expert witnesses. The jury should be instructed that it is not bound to the testimony of any or all experts, and the jury should determine what weight to give each expert’s testimony and the credibility it will give each witness. Hull v. City of St. Louis, 40 S.W. 89 (Mo. 1897). Furthermore, opinion evidence presented by expert witnesses is not necessarily “conclusive on the jury.” Cosgrove v. Leonard, 33 S.W. 777 (Mo. 1896). If the jury feels expert testimony is unreasonable, the jury has authority to disregard that expert’s testimony when deliberating and deciding the case. Hoyberg v. Henske, 55 S.W. 83 (Mo. 1899).
