In this case, Defendant was charged with the manufacture, possession and possession with intent to distribute marihuana as a result of a search of his home and vehicle on December 3, 2007.  Defendant stated to the police who executed the search that the marihuana was for medical use.  While criminal charges were pending, the MMMA became effective on December 4, 2008.

Defendant moved to dismiss the charges based on the MMMA's affirmative defense provision, MCL 333.26428.  The trial court granted Defendant's motion, leading to this appeal.

In general, statutes operate prospectively absent an intention for retroactive effect; however, there is an exception to the general rule for remedial statutes.  "A statute is remedial if it operates in furtherance of an existing remedy, and neither creates nor destroys existing rights."

In reversing the lower court's decision, the Court of Appeals concluded the MMMA is not a remedial statute, and therefore may not be applied retroactively, because it created a new substantive right: an affirmative defense to a criminal defendant facing prosecution for crimes related to the use of marihuana that did not exist prior to the enactment of the MMMA.