What is the test for proving an allegation of sexual assault against a defendant other than the one with which they are charged?

2 Regarding the evidence introduced in this case concerning the commission of offenses, if any, by the defendants other than the one with which they are charged, I instruct you that it is not necessary to prove all of the elements of each of such other offense beyond a reasonable doubt. It is sufficient if you find that the evidence, if any, concerning other offenses is established by competent proof sufficient to arouse more than a mere suspicion and that such evidence must afford substantial proof that the other offenses, if any, were in fact committed by the defendants or either of them, having in mind all of the other instructions relative to the limited purpose for which such other offenses are to be considered. People v. Lisenba, 14 Cal.2d 403, 94 P.2d 569; People v. Albertson, 23 Cal.2d 550, 145 P.2d 7.