What is the test for determining whether a defendant is guilty beyond a reasonable doubt?

defendant guilty beyond a reasonable doubt. [Citation.] . . . We presume in support of the judgment the existence of every fact the trier of fact reasonably could infer from the evidence. [Citation.] If the circumstances reasonably justify the trier of fact's findings, reversal of the judgment is not warranted simply because the circumstances might also reasonably be reconciled with a contrary finding. [Citation.] A reviewing court neither reweighs evidence nor reevaluates a witness's credibility." (People v. Lindberg (2008) 45 Cal.4th 1, 27.)

"'Although it is the duty of the jury to acquit a defendant if it finds that circumstantial evidence is susceptible of two interpretations, one of which suggests guilt and the other innocence [citations], it is the jury, not the appellate court which must be convinced of the defendant's guilt beyond a reasonable doubt. If the circumstances reasonably justify the trier of fact's findings, the opinion of the reviewing court that the circumstances might also reasonably be reconciled with a contrary finding does not warrant a reversal of the judgment.'" (People v. Thomas (1992) 2 Cal.4th 489, 514.)

2. Torture Special Circumstance Allegation