Can a defense counsel be ineffective in not seeking exclusion under Miranda?

^23. Because appellants could not suppress this evidence under Miranda, appellants cannot establish that their respective trial counsel were constitutionally ineffective in not seeking exclusion under Miranda. (See People v. Scheer, supra, 68 Cal.App.4th at p. 1024 [defense counsel not required to make futile motions or indulge in idle acts to appear competent].) Further, because any error was harmless, appellants cannot establish prejudice. (Strickland v. Washington (1984) 466 U.S. 668, 687 [the defendant has burden of showing both deficient performance and resulting prejudice].) Thus, we will not analyze further appellants' arguments their defense counsel rendered ineffective assistance in this regard.