http://www.bbc.com/news/world-us-canada-38514759Highlights
Injured the guy while live streaming, including removing part of his scalp
Kept a running commentary of racist and anti-Trump dialog
May have kept the guy kidnapped for two days
two male and two female, aged 18, African Americans, have been arrested
Police were particularly insightful.
Police Commander Kevin Duffin said the police would investigate whether a hate crime had taken place.
"They're young adults, and they make stupid decisions," he said, and, in reference to the language used, investigators would seek to "determine whether or not this is sincere or just stupid ranting and raving", he said.
Police also said there was a possibility that the incident would be considered a kidnapping.
There you have it. With video footage, they're unable to as yet determine if hate crime, kidnapping, etc have occurred but will investigate. It may have just been stupid ranting and raving. With the superior leadership of people like Kevin Duffin, no wonder why Chicago has such a low crime rate and a reputation for safety.