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You have posted variations on this question at least 3 times now, two of which I have answered. If you were in possession of 4 lbs of mj you are not 215 compliant and are subject to the charges you cite. Maybe an attorney can help you beat the charges but it won't be because you have a med mj card.
There are many medical marijuana attorneys in Northern California. Just having a MMJ card alone is not all you need. You need to have an aggressive and experienced attorney who knows how to parlay those facts in your benefit.
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The difficulty is finding a Dr. willing to testify on your behalf, there are plenty of good defense attorneys in town. Most Dr.s will charge $1000 to $2000 a day to testify. This is an affirmative defense which means you have to do the heavy lifting at trial.