SAN DIEGO COURTS — A Navy veteran who was the manager of a medical marijuana dispensary was acquitted of five charges of possessing and selling the drug illegally yesterday, a verdict that emboldened medical marijuana activists and was a setback for San Diego prosecutors who have aggressively pursued medical marijuana cases.

Jovan Jackson blinked, began to sigh, then started to weep as the court clerk in San Diego Superior Court Judge Cynthia Bashant's courtroom ticked off one "not guilty" verdict after another on the possession and sales of marijuana charges he faced.

Jackson was convicted of possessing the drugs Ecstasy and Xanax, however. Those charges were not the focus of the case, and he likely will not spend time in prison for them.

After the trial, which began Nov. 20, the jury foreman said that the ambiguity and lack of clarity in California's medical marijuana law tipped the balance in favor of Jackson.

Ed Fowler said the law is unclear on the definition of a collective or cooperative, so the panel had to find Jackson not guilty.

Jackson, 31, was the manager of the Answerdam Alternative Care in Kearny Mesa. San Diego prosecutors alleged that instead of dispensing medicine, Jackson was in the business of illegally selling the drug for profit.

Prosecutor Chris Lindberg argued that the dispensary sold marijuana to anyone who came in. San Diego police conducted undercover purchases in June and July of last year. One detective paid a $20 membership fee and provided a doctor's recommendation but signed up with a false name.

At the trial, Jackson's lawyer, Lance Rogers, argued that the dispensary complied with the law, requiring members to have a doctor's recommendation to use the drug and sign a membership agreement.

The jury deliberated about a day before reaching its verdict. Perry Wright, another juror, said afterward that clarifying the state's medical marijuana law is needed if there are to be more prosecutions.

"If you are going to hold someone to the law, you have to define that law," Wright said.

Medical marijuana activists said the verdict should send a message to District Attorney Bonnie Dumanis about bringing more cases and to local law enforcement that has orchestrated raids on cooperatives.

"I hope today this sends a signal that this has to stop," said Donna Lambert, a medical marijuana patient who was in the courtroom for the verdict and supported Jackson.