Edward “Robbie” Robinson at DeMatha football practice in 2015. (File photo)

Edward “Robbie” Robinson, a 2015 DeMatha graduate and All-Met honorable mention, was arrested Friday night in Tempe, Ariz., after posting threats on Twitter claiming he intended to shoot people at Arizona State’s athletic facilities.

Robinson, in more than 100 tweets posted Friday to his account, @RobThaProphet, said that he was attempting to purchase a gun to “spray the stadium.” Arizona State released an emergency alert about the threats at the Tempe campus.

“The system worked,” ASU spokesman Bret Hovell said. “This was an incident where apparently a young man with some sort of anger issue took to social media and was fighting with teammates over social media. Those teammates were encouraging him to get help.”

Robinson, 20, was arrested off-campus around 8 p.m. Friday on felony charges of knowingly interfering with an educational institution, marijuana possession and drug paraphernalia possession, per online court records via Maricopa County Superior Court. Each charge carries a maximum two-year prison sentence.

“A number of people called the ASUPD and they worked with their colleagues with law enforcement across the area,” Hovell said. “He was taken into custody without incident.”

Robinson was initially charged with making “terroristic threats,” which is punishable by nine years in prison, according to multiple news reports. But that charge does not appear in online court documents.

He is being held on $50,000 bond and has a court appearance scheduled for March 2.