NBC News is reporting that a man has been arrested in connection with an online threat that prompted the University of Chicago to cancel classes Monday, although its tweet announcing the news is missing some critical details.

The threat, which is being investigated by the FBI, seems to be a direct response to the release of dash-cam video of Chicago police officer Jason Van Dyke, who was charged with first-degree murder last week right before the court-ordered release of the video, which appears to show Van Dyke shooting black Chicago teen Laquan McDonald 16 times.

Protesters in Chicago who marched last week and physically blocked the entrances to stores on Black Friday have adopted “16 shots!” as one of their chants. Not coincidentally, the threat sent to the University of Chicago said that 16 white male students and/or staff would be executed, followed by the killing of as many white police officers as possible.

Though NBC’s tweet says the suspect threatened to “execute approximately 16 students or staff,” the actual message was much more specific, particularly with concern to race.

KVUE has named the suspect as Jabari Dean, a 21-year-old student at the University of Illinois at Chicago:

Someone who saw Dean’s threat on social media called authorities on Sunday to express concern, according to the complaint. The FBI eventually identified Dean as the poster of message. When agents confronted Dean about the message at his home in Chicago, he acknowledged that he posted the message. He also told agents that he took the message down shortly after he had written it.