In a prosecution for possession of marijuana for sale and transportation of marijuana, where defendant asserts a Compassionate Use defense, the prosecution expert testifying that the marijuana was held for purpose of sale, need not qualify as a medical marijuana expert (disagreeing with People v. Chakos (2007) 158 Cal.App.4th 357). Appellant was driving his vehicle when he was stopped by police officers for playing loud music. When contacted by one of the officers, appellant produced a medical marijuana identification card and informed the officer that there was marijuana in his car. Searching the vehicle and appellant, officers found a single bag with 17.2 grams of marijuana in appellant’s pocket; 10 plastic baggies, each containing 3 grams of marijuana, in the drivers door; 3 individuals baggies, each containing 6.5 grams of marijuana, in the back seat; and a WD-40 can with a hidden compartment containing marijuana residue. At trial, the prosecution’s expert testified as to his opinion that the marijuana was possessed for sale; appellant testified that the marijuana was medical marijuana for a health condition. He was convicted of transportation and possession of marijuana for sale. The appellate court rejected appellant’s argument that there was insufficient evidence to support the convictions because there was no evidence that the officer had expertise in differentiating the citizen who lawfully possesses marijuana from one who unlawfully possesses it with intent to sell. Because the Compassionate Use Act is an affirmative defense, the defendant has the burden of proof as to facts underlying the compassionate use defense. The court opined that the Chakos decision improperly reallocated the burden of proof to the prosecution, contrary to the principles articulated in People v. Mower (2002) 28 Cal.4th 1008 [“Application of the rule of convenience and necessity supports the conclusion that section 11362.5(d) (Compassionate Use Act) should be interpreted to allocate to the defendant the burden of proof as to the facts underlying the defense provided by the statute.”].