It wouldn't be in "case law", legal eagle. It would be found within state and municipal statutes.
But don't take my word for it:
Go here (Florida statutes -- isn't that where he lives?) -- and review Title XLVI, Section 893.13
Cool -- according to Title XLVI, Section 893.13 (6)(a), I'm committing a felony when my wife asks me to go to the medicine cabinet and bring her prescription medicine to her.