Mo. Rev. Stat. § 58.350: Evidence to be reduced to writing.

The evidence of such witnesses shall be taken down in writing and subscribed by them, and if it relate to the trial of any person concerned in the death, then the coroner shall bind such witnesses, by recognizance, in a reasonable sum for their appearance before the court having criminal jurisdiction of the county where the felony appears to have been committed, at the next term thereof, there to give evidence; and he shall return to the same court the inquisition, written evidence and recognizance by him taken.