What is the test for a jury to determine whether life without parole is the appropriate punishment in a murder case?

"The instructions were not impermissibly broad or vague in directing jurors to determine whether the aggravating factors were so substantial in comparison with the mitigating factors that it warrants death instead of life without parole. [Citation.]" (People v. Valdez (2012) 55 Cal.4th 82, 180, 144 Cal.Rptr.3d 865, 281 P.3d 924.)

CALJIC No. 8.88 properly conveys to the jury that life in prison without the possibility of parole is the appropriate punishment if the factors in mitigation outweigh those in aggravation. (People v. Jones (2012) 54 Cal.4th 1, 78-79, 140 Cal.Rptr.3d 383, 275 P.3d 496.)