There are no textbooks on the syllabus for the course Judith Cassel teaches on medical marijuana. The area of cannabis law is so in flux, she said, that any book would be out of date by the end of the semester. 

Tracking the ever-shifting cannabis regulatory landscape became a point of expertise for Cassel after Pennsylvania enacted its medical marijuana program in 2016. Since then, she has been entrenched in navigating the contradictions between state and federal law and working to ensure that regulations keep pace with science.