Okla. Stat. tit. 19, § 19-215.9: First assistant - Temporary appointments - Vacancies

The district attorney shall designate one of the assistants in

his district to be his first assistant district attorney and file

such designation with the Secretary of State. Should the district

attorney be absent, unable to attend to his duties, or disqualified

to act, the first assistant district attorney may perform the duties

required by law to be performed by the district attorney. In the

event that the district attorney and all of his assistants are for

any reason disqualified to act in a particular matter, the Attorney

General of Oklahoma shall appoint a district attorney or assistant

district attorney from another district to act in such matter.

Whenever the office of district attorney shall be vacated by reason

of resignation or death of the district attorney, the Governor of

the State of Oklahoma shall appoint a qualified person to serve the

balance of the unexpired term of said office.