Ohio Rev. Code § 145.334
A member who, on the effective date of this section, meets the definition of bureau of criminal identification and investigation investigator, gaming agent, department of taxation investigator, special police officer for a port authority, or special police officer for a municipal airport in section 145.01 of the Revised Code may make the election to be considered a PERS law enforcement officer or PERS public safety officer by giving notice to the public employees retirement system on a form provided by the public employees retirement board. To be valid, the notice must be received by the retirement system not later than ninety days after the effective date of this section . The election, once made, causes the member to be considered a PERS law enforcement officer or PERS public safety officer and is irrevocable.
Service credit earned by a member of the public employees retirement system before the first day of the first month following the retirement system's receipt of the notice of election shall not be considered service credit as a PERS law enforcement officer or PERS public safety officer.
R.C. § 145.334