Mo. Rev. Stat. § 58.470
Whenever an inquest shall be held, and the coroner shall have good reason to believe that the deceased came to his death by poison administered by the hand of some person other than the deceased, he may, at the request of the jury, cause chemical analysis and microscopical examination of the body of the deceased, or any part of it, to be made; and the testimony of medical and chemical experts may be introduced for the purpose of showing how and in what manner the deceased came to his death; and the coroner shall certify to the county commission of his county the fact of such analysis or examination, and testimony of such medical or chemical experts, and that the same was, in his opinion, necessary to an examination into the cause of the death of the deceased; and the commission shall allow such fees or compensation for such analysis, examination or medical or chemical testimony of experts as shall be deemed by said commission to be just and reasonable.
§ 58.470, RSMo