Ohio Rev. Code § 2937.19
The magistrate or judge or clerk of the court in which proceedings are being had may issue subpoenas or other process to bring witnesses or documents before the magistrate or court in hearings pending before him either under Chapter 2937. or 2938. of the Revised Code.
In complaints to keep the peace a subpoena must be served within the county, or, in cases of misdemeanors and ordinance offenses, it may be served at any place in this state within one hundred miles of the place where the court or magistrate is scheduled to sit; in felony cases it may be served at any place within this state. In cases where such process is to be served outside the county, it may be issued to be served either by the bailiff or constable of the court or by a sheriff or police officer either by the county in which the court or magistrate sits or in which process is to be served.
R.C. §2937.19