Washington ? In one corner of Washington state, a 62-year-old rheumatoid arthritis patient could face more than eight years in prison for growing marijuana for himself and three others. In Seattle, meanwhile, a collection of grow operations serves 2,000 people with little interference from police.

The discrepancy is typical of the confusion that has reigned since voters passed Washington’s medical marijuana law more than a decade ago. Nor have things improved much since the state clarified how much pot patients can have last year.

Unlike some states, Washington requires patients to grow marijuana themselves or designate a caregiver to grow it for them. For many, that’s unrealistic: They’re too sick to grow cannabis themselves and don’t have the thousands of dollars it can cost for a caregiver to set up a proper growing operation.

So they’ve devised their own schemes, claiming to meet the letter of the law in establishing collective grows or storefront dispensaries — methods that are making police and prosecutors increasingly uncomfortable.