(CNN) – A young woman who broadcast the beating of a man on Facebook Live has been arrested with three others in connection with the gruesome attack, Chicago Police said Wednesday.

The disturbing 30-minute video shows a man tied up and his mouth covered, cowering in the corner of a room. His attackers laugh and shout “f*ck Donald Trump” and “f*ck white people” as they kick and punch him and and cut into his forehead with a knife.

Police described the victim as an 18-year-old with special needs who was taken from the suburbs. Patrol officers found the disoriented young man wandering the street “in crisis” Tuesday afternoon and brought him to a hospital.

He was so traumatized that it took most of the night for him to calm down to the point that he was able to talk to police, 11th District Captain Steven Sesso said. It’s unclear how long he was missing, but it could have been between 24 and 48 hours.

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