What is the test for admitting evidence in a sexual assault case?

^4. Evidence Code section 402, subdivision (b), provides in relevant part that [t]he court may hear and determine the question of the admissibility of evidence out of the presence or hearing of the jury.... (Italics added.)

Evidence Code section 403, subdivision (a)(1), provides in relevant part that when the relevance of proffered evidence depends on the existence of foundational facts, [t]he proponent of the proffered evidence has the burden of producing evidence as to the existence of the preliminary fact, and the proffered evidence is inadmissible unless the court finds that there is evidence sufficient to sustain a finding of the existence of the preliminary fact. (See also Evid.Code, 405 [addressing the trial court's duty to evaluate preliminary facts related to evidentiary rules of exclusion]; People v. Cottone (2013) 57 Cal.4th 269, 282287, 159 Cal.Rptr.3d 385, 303 P.3d 1163 [discussing the distinction between Evid.Code 403 and 405].)

Evidence Code section 403, subdivision (a)(1), provides in relevant part that when the relevance of proffered evidence depends on the existence of foundational facts, [t]he proponent of the proffered evidence has the burden of producing evidence as to the existence of the preliminary fact, and the proffered evidence is inadmissible unless the court finds that there is evidence sufficient to sustain a finding of the existence of the preliminary fact. (See also Evid.Code, 405 [addressing the trial court's duty to evaluate preliminary facts related to evidentiary rules of exclusion]; People v. Cottone (2013) 57 Cal.4th 269, 282287, 159 Cal.Rptr.3d 385, 303 P.3d 1163 [discussing the distinction between Evid.Code 403 and 405].)

^5. We discuss, post, defendants' separate challenges to the court's rulings admitting various items of evidence.

^6. The law of the case doctrine states that when, in deciding an appeal, an appellate court states in its opinion a principle or rule of law necessary to the decision, that principle or rule becomes the law of the case and must be adhered to throughout its subsequent progress, both in the lower court and upon subsequent appeal ..., and this although in its subsequent consideration this court may be clearly of the opinion that the former decision is erroneous in that particular. ( Kowis v. Howard (1992) 3 Cal.4th 888, 892893, 12 Cal.Rptr.2d 728, 838 P.2d 250.)