Where a defendant defends against a charge of possession of marijuana for sale by introducing evidence that under the Compassionate Use Act and Medical Marijuana Program he legally possessed the marijuana, evidence supporting an officer’s opinion testimony may be sufficient to support a conviction. Appellant was charged with possession of marijuana for sale. At trial, he presented evidence that he had a prescription for marijuana for treatment of a medical condition. The prosecution presented the testimony of the arresting officer who opined that the marijuana was possessed for purposes of sale. On appeal, appellant contended that the officer’s opinion testimony was insufficient to support the conviction because it was not established that he had the experience in differentiating those who possess marijuana lawfully for medical purposes from those who possess it unlawfully with the intent to sell. Affirmed. To the extent appellant argued that the officer’s expert opinion was inadmissible or insufficient because the officer was unqualified, the issue was forfeited for failure to object in the trial court. Despite the lack of objection, appellant can still argue on appeal that the evidence, including the officer’s opinion, was insufficient to support the conviction. Here, however, the court found that the evidence was sufficient. The officer’s training and experience established that he was trained in law enforcement and the policing of illegal drug possession, and the circumstances of the possession itself supported a finding that appellant possessed the marijuana with intent to sell; i.e., the packaging and categorizing by weight of the marijuana, indicia that appellant accepted cash only, appellant’s prior conviction for possession of marijuana for sale, and appellant’s current financial situation. (People v. Hunt (1971) 4 Cal.3d 231 and People v. Chakos (2007) 158 Cal.App.4th 357 distinguished.)