CARBONDALE, Ill. (AP) — Authorities say an anonymous video calling for racial violence at Southern Illinois University in Carbondale was made by a Chicago-area man with no connection to the campus.

The video led to heightened racial tensions after it was posted on YouTube in April. The university’s leader condemned it, and YouTube later removed the video.

The Southern Illinoisan reports detectives at the Southern Illinois University Carbondale Department of Public Safety, the FBI and local prosecutors determined a 19-year-old white male who lives near Chicago made the video.

They say he admitted doing it as a prank. He’s not affiliated with any groups involved in campus protests, or the fraternity referenced in the video.

Jackson County State’s Attorney Mike Carr is declining to prosecute, saying the video could be considered protected speech.