What is the effect of a defendant waiving his Miranda right during an interview?

The case is analogous to People v. Silva (1988) 45 Cal.3d 604, 247 Cal.Rptr. 573, 754 P.2d 1070. There, the defendant waived Miranda rights and answered several questions, then refused to answer a question that might place him at the site where the murder victim was kidnapped. The interrogation continued, with the defendant answering some questions and not others. We concluded that the defendant's constitutional rights were not violated, because "[a] defendant may indicate an unwillingness to discuss certain subjects without manifesting a desire to terminate `an interrogation already in progress.'" (45 Cal.3d at pp. 629-630, 247 Cal.Rptr. 573, 754 P.2d 1070.) The same is true here.

Describing himself as a habitual user of methamphetamine, defendant argues that his responses during the interrogation suggest he was under the influence of that substance. Defendant, however, specifically denied being under the influence of alcohol or narcotics at the time of the interview. Contrary to counsel's suggestion, we cannot determine from defendant's conversational pattern in a written transcript whether he was under the influence of methamphetamine, and if so, to such an extent that he was not competent to waive his rights. Moreover, defendant's failure to raise this issue in the trial court bars him from asserting it on appeal. (See People v. Kipp (2001) 26 Cal.4th 1100, 1130, 113 Cal.Rptr.2d 27, 33 P.3d 450; People v. Ray (1996) 13 Cal.4th 313, 339, 52 Cal.Rptr.2d 296, 914 P.2d 846.)