Can a percipient witness provide sufficient evidence to satisfy the subjective element of sustained fear?

A victim need not testify that he or she was in sustained fear in order to satisfy this element. Whether the victim was in sustained fear can be inferred from the evidence. (People v. Ortiz (2002) 101 Cal.App.4th 410, 417.) Similarly, a percipient witness "could conceivably testify to having observed a person targeted by another's criminal threat actually experienced sustained fear and, in so doing, supply sufficient evidence of the subjective element." (In re Sylvester C., supra, 137 Cal.App.4th at p. 606.)