(1) The supreme court shall consider the punishment as well as any errors enumerated by way of appeal. With regard to the sentence, the court shall determine:
(a) whether the sentence of death was imposed under the influence of passion, prejudice, or any other arbitrary factor;
(b) whether the evidence supports the trier of fact's finding of the existence or nonexistence of the aggravating circumstances enumerated in 46-18-303 and the sentencing judge's finding of the existence or nonexistence of the mitigating circumstances enumerated in 46-18-304; and
(c) whether the sentence of death is excessive or disproportionate to the penalty imposed in other cases in which a sentencing hearing was held pursuant to 46-18-301, whether the sentence imposed was death or a sentence other than death, considering both the crime and the defendant. The court shall include in its decision a reference to those other cases it took into consideration.
(2) The supreme court shall uphold the sentencing court's findings of fact issued pursuant to 46-18-306 unless those findings are clearly erroneous. The supreme court may not substitute its judgment for that of the sentencing court in:
(a) assessing the credibility of witnesses;
(b) drawing inferences from testimonial, physical, documentary, or other evidence; or
(c) resolving conflicts in the evidence presented at the sentencing hearing or considered by the sentencing court.