Mo. Rev. Stat. § 56.300: Prosecuting attorneys — duties, coroners' inquests (third and fourth class counties).

The prosecuting attorney in counties of the third and fourth class shall attend inquests by coroners in cases of death occurring by violence, and which may result in a charge of felony. The prosecuting attorney shall make an investigation concerning the death and cause to be brought before the coroner any witnesses he desires. He shall be permitted by the coroner to assist in the interrogation of witnesses for the full development of the circumstances leading up to and resulting in the death, and for his information concerning any possible criminal charge that may grow out of the death.