In People v. Edwards (1991) 54 Cal.3d 787, defendant drove his truck slowly toward two girls at a camp site, turned his truck around, and then followed them for about a quarter mile as the girls walked to a picnic spot for lunch. As the girls were walking, defendant drove alongside them, stopped, and said, "Girls." (Id. at pp. 804-805.) Defendant immediately fired two shots from a pistol, first at one girl, then at the other. (Id. at p. 805.) The court found sufficient evidence to support the lying-in-wait special circumstance finding. (Id. at pp. 825-826.) On the element of concealment of purpose, the court observed: "Defendant drove alongside the victims where there were no witnesses and where they would be most vulnerable. While they were completely unsuspecting, he called to them so they would look his way and become ideal live targets. After gaining this position of advantage, he shot and killed." (Id. at p. 825.) "An ambush or a 'situation where the victim is taken unawares and by surprise,' combined with an intent to kill, necessarily places the intended killer in a position of advantage." (Id. at p. 823.) The court also found evidence of a substantial period of watching and waiting in the "minutes" that elapsed during the quarter mile that defendant followed the victims. (Id. at p. 826.) The court noted that "we have never required a certain minimum period of time, only a period not insubstantial." (Id. at p. 823.) On appeal in Edwards, the defendant argued he was entitled to a reversal since the trial court excluded critical defense evidence. The Edwards court concluded that the defendant was not "unavailable as a witness" within the meaning of section 240, defining the "unavailability of a witness." The Edwards court explained: "Defendant was certainly not unavailable to himself. Although he possessed, and exercised, a privilege not to testify, the choice was his. He could have testified had he so elected." (Edwards, supra, 54 Cal.3d at p. 819.) The trial court pointed out that the Comment of the Assembly Committee on the Judiciary to section 240, states "'if the out-of-court statement is that of the party himself, he may not create "unavailability" under this section by invoking a privilege not to testify.'" ( Edwards, supra, at p. 819.) The Edwards court also commented, under sections 1250, 1251 and 1252, the statements the defendant sought to admit were unreliable. They were made when the defendant had a "compelling motive to deceive and seek to exonerate himself from, or at least to minimize his responsibility for, the shootings." ( Edwards, supra, 54 Cal.3d at p. 820.) The court pointed out there was ample ground to suspect the defendant's motives in making the statements and, in those circumstances, the "need for cross-examination is especially strong" and "fully warrants exclusion of the hearsay evidence." (Ibid.) The court concluded the following rule was applicable in the circumstances: "'A defendant in a criminal case may not introduce hearsay evidence for the purpose of testifying while avoiding cross-examination.'" (Ibid.)