(a) The appointing authority shall issue a certificate of appointment to each person appointed as a special policeman under Code Sections 35-9-2 through 35-9-4, this Code section, and Code Sections 35-9-6 through 35-9-14 in such form as it may prescribe.

(b) The certificate of appointment shall constitute the appointee's authority for exercising the powers and carrying out the duties conferred and imposed upon him by Code Sections 35-9-2 through 35-9-4, this Code section, and Code Sections 35-9-6 through 35-9-12.