The man being assaulted has special needs, police say. His assailants can be heard making derogatory statements against white people and President-elect Donald Trump. In one part of the video they use a knife to remove part of his scalp. Chicago police have described the video as a "sickening" possible hate crime.
"It makes you wonder what would make individuals treat somebody like that," Chicago Police Superintendent Eddie Johnson said in a press conference streamed on Twitter.