The U.S. Court of Appeals for the D.C. Circuit on Monday considered the breadth of the federal trespassing law in weighing whether to overturn a former President Donald Trump supporter’s misdemeanor conviction for illegally being on U.S. Capitol grounds during the Jan. 6, 2021, riot.

The arguments in Cowboys for Trump founder Couy Griffin’s appeal centered on the statutory meanings of “restricted grounds” and “knowingly.”