What is the effect of section 190.3 of the Eighth Amendment on the sentencing of a defendant in a murder trial?

The jury was instructed, in accordance with section 190.3: "If you conclude that the aggravating circumstances outweigh the mitigating circumstances, you shall impose a sentence of death." Defendant contends that this instruction precluded the jury from exercising its sentencing discretion as required by the Eighth Amendment. In People v. Brown (1985) 40 Cal.3d 512, 538-545, 230 Cal.Rptr. 834, 726 P.2d 516 (cert. den. on other grounds, 479 U.S. 538, 107 S.Ct. 837, 93 L.Ed.2d 934), we held that section 190.3 must be interpreted as directing determination of the penalty not on the basis of any mechanical formula, but through a balancing process in which each juror assigns to each factor the weight that he or she deems appropriate and decides which penalty is appropriate under all the circumstances. (Id. at p. 541, 230 Cal.Rptr. 834, 726 P.2d 516.) We further held that in subsequent trials, the jury should be instructed in accordance with the principles we were announcing, and that prior cases must be examined to determine whether, in context, the sentencer may have been misled to defendant's prejudice concerning the proper scope of its sentencing discretion. (Id. at p. 544, fn. 17, 230 Cal.Rptr. 834, 726 P.2d 516.)