Okla. Stat. tit. 16, § 9

At least thirty (30) days before the hearing of the petition, the applicant or his attorney shall serve a copy of the petition upon the nearest competent relative of the incapacitated spouse in this state. If there is no such relative known to the applicant, a copy of the petition shall be served upon the district attorney of the county in which the homestead is located. The district attorney, if served with a copy of the petition, shall appear in court and see that the application is made in good faith and that the proceedings thereon are fairly conducted.