Okla. Stat. tit. 43A, § 43A-1-108: Habeas corpus - Notice - Evidence

A. Anyone in custody as a person in need of treatment, assisted

outpatient or a minor in need of mental health treatment, pursuant

to the provisions of this title, is entitled to a writ of habeas

corpus, upon a proper application made by such person or some

relative or friend in the person's behalf pursuant to the provisions

of Sections 1331 through 1355 of Title 12 of the Oklahoma Statutes.

B. Upon the return of a writ of habeas corpus, whether the

person is a person requiring treatment or an assisted outpatient as

defined by Section 1-103 of this title or whether the minor is a

minor requiring treatment as defined by Section 5-502 of this title

shall be inquired into and determined.

C. Notice of hearing on the writ must be given to the guardian

of the consumer, if one has been appointed, to the person who

applied for the original commitment and to such other persons as the

court may direct.

D. The medical or other history of the consumer, as it appears

in the facility record, shall be given in evidence, and the

executive director of the facility wherein the consumer is held in

custody shall testify as to the condition of the consumer.

E. The executive director shall make available for examination

by physicians selected by the person seeking the writ, the consumer

whose freedom is sought by writ of habeas corpus.

F. Any evidence, including evidence adduced in any previous

habeas corpus proceedings, touching upon the mental condition of the

consumer shall be admitted in evidence.