KANSAS CITY (AP) – A Missouri appeals court has upheld a lower court’s ruling that evidence of a marijuana-growing operation found in a university professor’s home can’t be used against him because of an invalid search warrant.

Matthew Rouch was a professor in Northwest Missouri State University’s Communications Department when he made what he thought was a humorous comment on Facebook in August 2013 about wanting to go to the top of the campus bell tower with a rifle and gatling gun.

Campus police were notified of the comment and got a warrant to search his home for guns, but instead found evidence of a marijuana growing operation.

A Nodaway County court granted Rouch’s motion to suppress the evidence because the search warrant was invalid, and on Tuesday the Missouri Court of Appeals concurred.