Steven Nelson, US News & World Report

A group of medical marijuana patients prevailed Tuesday in their fight against most - but not all - felony charges brought by federal prosecutors in Washington state.

A jury found three members of the so-called "Kettle Falls Five" guilty of one federal crime: growing between 50 and 100 plants, which they admittedly did in a collective garden that roughly complied with state medical marijuana law.

But the defendants were acquitted of felony charges for alleged distribution, conspiracy, cultivation of more than 100 plants and use of firearms in furtherance of a drug trafficking crime.

The long-running case attracted national attention and pitted a plucky family of four – plus a family friend – against a zealously anti-marijuana U.S. attorney's office in a state that allows recreational use of the drug.

One original defendant, family patriarch Larry Harvey, was excused from the case prior to trial because he has terminal cancer. Harvey traveled to the nation’s capital last year to campaign for a budget amendment Congress passed to protect state medical pot laws from federal interference.

Infuriated activists say prosecutors in the case failed to heed the Department of Justice’s 2009 guidance against prosecuting patients in medical marijuana states and ignored the wishes of Congress.

Americans overwhelmingly support medical marijuana, according to polls, but at trial the patients were not allowed to say they grew the drug for state-permitted medical use.

Possession of marijuana for any reason outside limited research is a federal crime, regardless of state laws allowing medical or recreational use. Prosecutors and judges presiding over the case decided informing the jury about state law would be confusing and irrelevant.

The defendants' rural garden in eastern Washington was raided by the Drug Enforcement Administration in 2012 after local officials found 74 plants. State law allows patients to grow 15 plants each, up to 45 plants in collective gardens. Prosecutors cited photos from the previous year to allege more than 100 plants were grown, a violation that carries a five-year mandatory sentence.

The defendants' gun ownership – the weapons were for hunting, they successfully argued – could have yielded another mandatory five-year sentence. 

The advocacy group Americans for Safe Access, which worked intimately on the case, celebrated the outcome.

"The jury saw through the deceit of the federal government and rightly acquitted on almost all charges," Kris Hermes, a spokesman for the group, said in a statement. "This should signal to the Department of Justice that prosecutions such as the Kettle Falls Five are a waste of time and money and, if anything, should be left to state courts."

Americans for Safe Access estimates the prosecution cost the federal government $2 million.

U.S. District Judge Thomas Rice denied a prosecution request to immediately imprison the defendants Tuesday, the Spokesman-Review reports. Sentencing is currently scheduled for June 10. They may face years in prison, but will be allowed to describe their reason for growing the drug at sentencing.