Does the Attorney General have a burden to prove that the criminal action commenced before the expiration of the statute of limitations?

²Defendant did not argue in the trial court that the prosecution had failed to carry its burden to prove the criminal action had commenced before the expiration of the statute of limitations. Instead, as described in detail, post, defendant argued in a pretrial proceeding that application of former Penal Code section 803, subdivision (i), to him would violate his constitutional due process rights as an ex post facto extension of the limitations period. At trial, defendant correctly argued that the time of commencement of a criminal prosecution was a legal issue for the court, not the jury, to determine. In a discussion with the trial court and the district attorney concerning the jury instruction on the statute of limitations, defendant's trial counsel stated he was certainly not in the position of admitting anything. The Attorney General does not argue on appeal that the issue of sufficiency of the evidence regarding commencement of a criminal prosecution has been waived. Indeed, a challenge to the sufficiency of evidence is forfeited in the trial court only by failure to file a timely notice of appeal. ( People v. Rodriguez (1998) 17 Cal.4th 253, 262, 70 Cal.Rptr.2d 334, 949 P.2d 31.) The issue of sufficiency of the evidence is before us and we next address it on the merits.