In what circumstances will a defendant be found guilty of manufacturing methamphetamine even if he did not know that methamphetamine was being manufactured?

This instruction was derived from People v. Telfer [[, supra,]] 233 Cal.App.3d 1194 [284 Cal.Rptr. 913], which held that manufacturing of methamphetamine is a strict liability offense, i.e., knowledge of the physical character of the substance being manufactured is not an element of the offense and, "[s]o long as the product of the defendant's activity was methamphetamine ..., the defendant is guilty, even if he did not know that methamphetamine would be that product." (Id., at p. 1204 (284 Cal.Rptr. 913).)

For reasons that follow, we disagree with the reasoning of People v. Telfer, supra, 233 Cal.App.3d 1194 (284 Cal.Rptr. 913), which analogized section 11379.6 to strict liability "public welfare" statutes that generally are regulatory in nature, impose light penalties, have little "damage to reputation," and thus have no mens rea requirement. As we shall explain, the crime of manufacturing methamphetaminea felony punishable by incarceration in state prisonmust be interpreted to include as an element of the offense the accused's knowledge of the character of the substance being manufactured. Hence, the trial court's instruction to the contrary was erroneous. As the error was prejudicial, we shall reverse the judgment.