Is proof of guilt of a crime by a unanimous jury required at the penalty phase of a death penalty trial?

Obviously, proof of guilt of a crime by a unanimous jury is one of the "safeguards ... which protect [a defendant] in the trial in which guilt is established." (See People v. Terry, supra, 61 Cal.2d at p. 149, fn. 8, 37 Cal.Rptr. 605, 390 P.2d 381.) Inasmuch as this court has incorporated into the penalty phase the guilt-trial protections which range from the corpus delicti rule to the beyond a reasonable doubt standard, it is inconceivable that the court did not intend and assume that the vital protection of juror unanimity would also be accorded a defendant at a penalty trial. To allow a death verdict to be based upon a showing which would not result in a conviction is to undermine the stringent rules of proof carefully constructed to protect against hasty and ill-founded death penalty determinations.

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