A related hypothetical question: what if copters spot growing plants on your property and you want to plead a necessity defense, that you grew Cannabis for personal medical use when all other remedies were not tolerated or too risky to try. Doesn't the necessity defense _require_ defendant's evidence of her medical condition and history? Isn't it a deprivation of that common law defense to bar testimony necessary to prove it? I believe the N.J.Super. got it wrong on this one. Help us, App.Div.
I don't believe a judge would allow it, no.
First off, being a common law defense it would only be a defense to violations of state law, not federal prosecutions. So it initially matters which court he's in. Not just state vs federal court, but which state in particular. For there will be wide variations in details of a necessity defense from state to state.
Second the necessity defense, afaik, is usually restricted to an urgent and immediate necessity. An emergency for all intensive purposes. If someone is chasing you with a knife, you can say break a store window to get away from him. Or better yet the police can break down your door, which would normally incur charges of trespass and breaking and entering, if they believe there's a dire medical emergency. In addition the harm caused has to be less grave than the harm prevented.
Third is the consideration of reasonable alternatives. You can't commit arson because you're cold. You can't steal food because you're hungry. That's because there are shelters and welfare benefits. In your hypothetical situation there would be marinol, oxycodone or a myriad of other alternatives to breaking the law.
That's my understanding of a necessity defense. Of course I could be wrong, I'm not a lawyer just a rational and logical sort of guy.http://en.wikipedia.org/wiki/United_States_v._Oakland_Cannabis_Buyers'_Cooperative
So curious I went and did a quick search. It appears it's been tried before, and the supreme court decided it's not a valid defense in federal cases.
Justice Thomas wrote for the majority. The OCBC contended that the Controlled Substances Act was susceptible of a medical necessity exception to the ban on distribution and manufacture of marijuana. The Court concluded otherwise.http://www.amarillo.com/stories/032808/new_9971268.shtml
Since 1812, the Court had held that there were no common-law crimes in federal law. See United States v. Hudson and Goodwin. That is, the law required Congress, rather than the federal courts, to define federal crimes. The Controlled Substances Act did not recognize a medical necessity exception. Thus "a medical necessity exception for marijuana is at odds with the terms of the Controlled Substances Act." When it passed the Controlled Substances Act, Congress made a value judgment that marijuana had "no currently accepted medical use." It was not the province of the Court to usurp this value judgment made by the legislature. Thus, it was wrong for the Ninth Circuit to hold that the Controlled Substances Act did contain a medical necessity defense. It was also wrong for the Ninth Circuit to order the district court to fashion a more limited injunction that would take into account the fact that marijuana was necessary for certain people to obtain relief from symptoms of chronic illnesses.
I also found this interesting case where a man in Texas evidently successfully convinced a judge to allow just such a defense and won an acquittal. Perhaps Texas being a historically conservative state, it's common law grants more freedom as a result of a social emphasis on individual liberty. Just a hunch. I can't be sure as the Texas Law Library's search function blows chunks. I can't even find the case.