As used in this chapter:

1. (A) "Killed in the line of duty" means either of the following:

   1. (1) Death in the line of duty;
   2. (2) Death from injury sustained in the line of duty, including heart attack or other fatal injury or illness caused while in the line of duty.
2. (B) "Totally and permanently disabled" means unable to engage in any substantial gainful employment for a period of not less than twelve months by reason of a medically determinable physical impairment that is permanent or presumed to be permanent.

3. (C) "Volunteer peace officer" means any person who is employed as a police officer, sheriff's deputy, constable, or deputy marshal in a part-time, reserve, or volunteer capacity by a county sheriff's department or the police department of a municipal corporation, township, township police district, or joint police district and is not either of the following:

   1. (1) A member of the public employees retirement system, Ohio police and fire pension fund, state highway patrol retirement system, or the Cincinnati retirement system;
   2. (2) A retirant as defined in section 145.01 of the Revised Code.