In what circumstances will a jury award the death penalty during the penalty phase?

In People v. Prieto (2003) 30 Cal.4th 226, we further explained that because the penalty jury merely weighs the factors enumerated in section 190.3 and determines whether a defendant eligible for the death penalty should in fact receive that sentence...' [citation] [n]o single factor therefore determines which penalty - death or life without the possibility of parole - is appropriate. []... [And] [b]ecause any finding of aggravating factors during the penalty phase does not increase[ ] the penalty for a crime beyond the prescribed statutory maximum' [citation], Ring imposes no new constitutional requirements on California's penalty phase proceedings. (Id. at p. 263.)