SPOKANE, Wash. - The green-cross storefronts of medical marijuana dispensaries are common in much of Washington, and the state is plowing ahead with licensing people to grow and sell recreational pot to adults.

But a federal trial scheduled to begin in the coming weeks for five people in Spokane suggests not all is OK with weed in the state.

Larry Harvey, a 70-year-old medical marijuana patient with no criminal history, three of his relatives, and a family friend each face mandatory minimum sentences of at least 10 years in prison after they were caught growing about 70 pot plants on their rural, mountainous property.

The Harveys did have guns at their home, which is part of the reason for the lengthy possible prison time. They say the weapons were for hunting and protection, but prosecutors say two of the guns were loaded and in the same room as a blue plastic tub of pot.

Medical marijuana advocates have cried foul, arguing the prosecution violates Department of Justice policies announced by Attorney General Eric Holder last year that nonviolent, small-time drug offenders shouldn't face lengthy prison sentences.

"This case is another glaring example of what's wrong with the federal policy on cannabis," said Kari Boiter, Washington state coordinator for the medical marijuana group Americans for Safe Access.

Assistant U.S. Attorney Joe Harrington, a spokesman for the U.S. Attorney's Office in Spokane, said he could not discuss the coming trial or the office's general approach to pot crimes.

But the case illustrates discrepancies in how law enforcement officials are handling marijuana cases as Washington - with the Justice Department's blessing - moves ahead with its grand experiment in pot legalization. Medical marijuana gardens the size of the Harveys' rarely draw attention from authorities in the Seattle area.

Under Initiative 502, about 30 people have so far been licensed to grow marijuana for sale at recreational pot shops scheduled to begin opening in July. Commercial medical marijuana dispensaries also operate in many cities, especially in western Washington, generally considered the liberal half of the state.

Under federal law, marijuana remains illegal, and what the licensed growers are doing differs little from what Harvey and his family did.