Questioning an officer at a suppression hearing when neither defendant nor his counsel is present requires reversal of the conviction. In a case involving multiple defendants, counsel for one defendant was absent during the conclusion of a suppression hearing due to a scheduling conflict. She indicated that she had been under the impression that the remainder of the hearing would consist only of redirect testimony related to one of the other defendants, but in fact about half of the testimony taken in her absence related to her client. Noting that a defendant need not show prejudice when defense counsel is absent for a critical stage of the proceedings, the Ninth Circuit found that the defendant had not knowingly and intelligently waived his right to counsel, and accordingly reversed the conviction and remanded for further proceedings.