Can evidence that was rejected as insufficient to constitute a statutory mitigating factor be considered as a non-statutory mitigating factor?

State v. Jeffers, 135 Ariz. 404, 661 P.2d 1105, 1129 (1983) (emphasis added). As this quotation demonstrates, the court announced that its discussion was restricted to the facts upon which the trial court relied in handing down its special verdict. It did not purport to consider whether evidence that the trial court rejected as insufficient to constitute a statutory mitigating factor could nevertheless be considered mitigating as a nonstatutory mitigating factor, under a less demanding standard than those prescribed for the five specific mitigating circumstances enumerated in the statute.