Does section 654 of the California Criminal Code apply where the prosecution failed to charge one of the crimes at the outset, but then subsequently prosecuted on the subsequent charge of possessing a .22 handgun?

Even where the proof of the offenses is entwined, section 654 does not apply where the prosecutor is unable to charge one of the crimes at the outset because facts essential to sustain the charge have not yet occurred or not yet been discovered by the prosecutor despite the exercise of due diligence. (People v. Davis (2005) 36 Cal.4th 510, 558.) Whether this exception applies is a question of fact. (Ibid.)

We do not need to decide whether the simultaneous possession of a .22-caliber handgun and unrelated .32-caliber ammunition is not an interrelated course of conduct involving the recycling of the same evidencewhich would preclude successive prosecution even though separately punishable. Such a determination is unnecessary because substantial evidence supports the trial court's finding that the prosecution lacked sufficient evidence to plead and prove the gun charge at the outset, and that the photograph which later provided the necessary evidence could not have been found with the exercise of due diligence. In other words, this subsequent prosecution on the gun charge falls within the exception to section 654 articulated in People v. Davis, supra, 36 Cal.4th at page 558.