Does the purpose of the murder is to prevent testimony in a criminal proceeding?

We may not, however, ignore the express provision of section 190.2, subdivision (a)(10), that the purpose of the murder is to prevent testimony in a criminal proceeding. Substantial evidence in the instant case supports a finding that defendant's purpose in killing Morganti was to prevent Morganti from testifying. However, there is virtually no evidence that defendant believed himself to be exposed to adult criminal process; thus there is no substantial evidence that defendant's purpose was to prevent Morganti from testifying in a criminal proceeding. Despite defendant's challenge to this special circumstance prior to trial and on the same basis, the only direct evidence presented to the jury about the nature of the proceeding in which defendant might expect Morganti to testify suggested only a juvenile proceeding, i.e., the chief deputy district attorney in charge of the juvenile division testified that he planned to file a petition charging burglary against defendant. Although not part of the evidence presented to the jury, the record before this court makes clear the fact that an offer of juvenile disposition of the burglary charge had, in fact, been communicated to defendant by his attorney. There was only one reference to defendant's belief about that proceeding made before the jury, i.e., that the most defendant would have gotten was "parole." Standing alone, defendant's statement concerning "parole" is ambiguous at best; considered with the evidence offered by the juvenile prosecutor, there is insufficient evidence to support the jury's verdict on this special circumstance. The failure of the trial court to instruct the jury ³ that defendant's belief as to the nature of the proceeding was an issue they must determine constitutes a failure to instruct on all applicable principles of law as required by People v. Wickersham, supra, 32 Cal.3d 307, 185 Cal.Rptr. 436, 650 P.2d 311, unless defendant's purpose to prevent the victim's testimony in a criminal proceeding would sustain a finding that the second special circumstance was true even if that proceeding were a juvenile court proceeding. Thus, as a matter of law, we are required to decide whether a juvenile court proceeding is a criminal proceeding for purposes of section 190.2, subdivision (a)(10).