Okla. Stat. tit. 21 § 701.11
In the sentencing proceeding, the statutory instructions as determined by the trial judge to be warranted by the evidence shall be given in the charge and in writing to the jury for its deliberation. The jury, if its verdict be a unanimous recommendation of death, shall designate in writing, signed by the foreman of the jury, the statutory aggravating circumstance or circumstances which it unanimously found beyond a reasonable doubt. In nonjury cases the judge shall make such designation. Unless at least one of the statutory aggravating circumstances enumerated in this act is so found or if it is found that any such aggravating circumstance is outweighed by the finding of one or more mitigating circumstances, the death penalty shall not be imposed. If the jury cannot, within a reasonable time, agree as to punishment, the judge shall dismiss the jury and impose a sentence of imprisonment for life without parole or imprisonment for life.
Okla. Stat. tit. 21, § 701.11