An appeals court has tossed the conviction of a woman who overdosed on heroin and was later charged with possession of a controlled substance, holding that immunity under the state’s Drug Overdose Response Act cannot be waived.

An en banc Superior Court panel found that defendant Sarah Markun could not be brought up on criminal drug charges related to her overdose because immunity under the act is not a defense that must be asserted. In doing so, the court vacated her conviction and sentence of one year of probation.