Can a defendant waive his right to remain silent at trial?

unless it demonstrates the use of procedural safeguards effective to secure the privilege against self-incrimination . . . . Prior to any questioning, the person must be warned that he has a right to remain silent, that any statement he does make may be used as evidence against him, and that he has a right to the presence of an attorney, either retained or appointed. The defendant may waive effectuation of these rights, provided the waiver is made voluntarily, knowingly and intelligently. If, however, he indicates in any manner and at any stage of the process that he wishes to consult with an attorney before speaking there can be no questioning.' " (People v. Neal (2003) 31 Cal.4th 63, 79-80.)