Can a jury consider the deterrent effect of the death penalty or the monetary costs of maintaining a prisoner for life without possibility of parole?

Defendant claims the trial court erred in refusing his instruction to the jury not to consider the deterrent effect of the death penalty or the monetary costs of executing a prisoner versus maintaining him in prison for life without possibility of parole. In rejecting the instruction, the trial court reasoned that the instruction might backfire and cause the jury to consider matters it would otherwise have ignored. We have noted that a jury was similarly instructed in People v. Ray (1996) 13 Cal.4th 313, 355, and footnote 22, 52 Cal.Rptr.2d 296, 914 P.2d 846. While instructing the jury on this point may be appropriate in some cases, it was not error for the trial court to refuse such an instruction. The jury was adequately informed that it was supposed to limit itself to the statutory aggravating and mitigating circumstances in making its penalty determination. The prosecutor never attempted to comment or introduce evidence regarding issues of cost and deterrence. The trial court was not required to furnish an instruction exhorting the jury to refrain from considering factors which, under a reasonable understanding of the jury instructions, it should have known were improper to consider.

E. Reasonable Doubt Instruction for Other Crimes Evidence