PC 4573 bars transporting “any controlled substance” into a correctional facility. People v. Blanco (Feb. 24, 2021, E073176) 61 Cal.App.5th 278 [pp. 12] concluded that “the Legislature intended for a usable quantity to be an element of section 4573.”
Accordingly, CC 2304 correctly requires the jury to find usable quantity as an element a charge of violating PC 4573.
But see, People v. Rubacalba (1993) 6 C4th 62, 64-67, holding that the usable-quantity rule prohibits conviction only when the substance possessed simply cannot be used, such as when it is a blackened residue or a useless trace. No particular purity or narcotic effect need be proven. (Ibid.; see also, State v. Baker (1995) 912 SW2d 541 [possession of a crack pipe containing burnt cocaine residue detectable through lab analysis but too small to measure will not sustain a conviction for possession of cocaine. Only a measurable quantity of a drug can sustain a conviction for possession. The residue present on the pipe indicates only that it had been used to smoke cocaine in the past and the most the defendant may be found guilty of is possession of drug paraphernalia].)
The Rubacalba court did note, however, that the concentration of the substance might in some situations be relevant to the element of knowledge. (Rubacalba, 6 C4th at 66.)
