Ohio Rev. Code § 313.17
The coroner or deputy coroner may issue subpoenas for such witnesses as are necessary, administer to such witnesses the usual oath, and proceed to inquire how the deceased came to his death, whether by violence to self or from any other persons, by whom, whether as principals or accessories before or after the fact, and all circumstances relating thereto. The testimony of such witnesses shall be reduced to writing and subscribed to by them, and with the findings and recognizances mentioned in this section, shall be kept on file in the coroner's office, unless the county fails to provide such an office, in which event all such records, findings and recognizances shall be kept on file in the office of the clerk of the court of common pleas. The coroner may cause such witnesses to enter into recognizance, in such sum as is proper, for their appearance to give testimony concerning the matter. He may require any such witnesses to give security for their attendance, and, if any of them fails to comply with his requirements he shall commit such person to the county jail until discharged by due course of law. In case of the failure of any person to comply with such subpoena, or on the refusal of a witness to testify to any matter regarding which he may lawfully be interrogated, the probate judge, or a judge of the court of common pleas, on application of the coroner, shall compel obedience to such subpoena by attachment proceedings as for contempt. A report shall be made from the personal observation by the coroner or his deputy of the corpse, from the statements of relatives or other persons having any knowledge of the facts, and from such other sources of information as are available, or from the autopsy.
R.C. §313.17