Okla. Stat. tit. 57, § 57-15: When a poor convict is held for fine and costs

When any poor convict shall have been confined in any prison for

the space of six (6) months, for nonpayment of fine and costs only,

or either of them, the sheriff of the county in which such person

shall be imprisoned shall make a report thereof to any two justices

of the peace for such county; if required by such justices, the said

keeper shall bring such convict before them, either at the prison,

or at such other convenient place thereto as they shall direct; the

said justices shall proceed to inquire into the truth of said

report, and if they shall be satisfied that the report is true, and

the convict has not had since his conviction any estate, real or

personal, with which he could have paid the sum for the nonpayment

of which he was committed, they shall make a certificate thereof to

the sheriff of the county, and direct him to discharge such convict

from prison and the sheriff shall forthwith discharge him.