According to A.J. Perez of USA Today, UCF Police Department chief Richard Beary explained the decision to evacuate: "We think it was some kind of stunt ... but unfortunately with the current threat situation the way it is, our fire partners are treating it as a hazmat situation. We are in the process of doing that."
The UCF Police Department later confirmed on Twitter that the powder used in the stunt was baby formula.
The police department also tweeted that the student was wearing a white Miami Heat jersey with James' name on the back at the time:
That was a play on James famously saying in 2010 that he was "taking [his] talents to South Beach" upon deciding to leave Cleveland for Miami in free agency.
As of Wednesday, campus police were still searching for the student.
After tossing chalk at the scorer's table for the first several years of his career, James ceased doing it in 2014 upon returning to Cleveland in free agency.
James won a pair of championships during his four-year stint in Miami. Since returning to the Cavaliers, he has reached three NBA Finals and helped the Cavs win their first-ever championship in 2016.