Ala. Code § 36-30-22
The provisions of this article shall apply to a law enforcement officer who, upon entering the service of the city or county as a law enforcement officer, has successfully passed a physical examination which failed to reveal any evidence of a law enforcement officer's occupational disease and who has completed at least three years' service as a law enforcement officer, provided a physical examination was required at the time of entry into service, and shall apply to a state law enforcement officer who, upon entering the service of the state as a law enforcement officer, successfully passed a physical examination which failed to reveal any evidence of a law enforcement officer's occupational disease and who has completed no less than three years' service as a state law enforcement officer.
Ala. Code § 36-30-22 (1975)