Cal. Penal Code § 1001.24

No statement, or information procured therefrom, made by the defendant to any probation officer, the prosecutor, or any regional center designee during the course of the investigation conducted by either the regional center or the probation department pursuant to this chapter, and prior to the reporting to the probation department of the regional center’s findings of eligibility and recommendations to the court, shall be admissible in any action or proceeding brought subsequent to this investigation.