(CBS) -- Four people are in custody after video was streamed online showing a duct-taped teen being tortured.
Police say the 18-year-old victimized in the video is a northwest suburban resident with special needs who had been reported missing.
In the video, believed to be from Tuesday, the victim's clothes were cut, he was peppered with cigarette ashes, and then his hair cut with a knife until his scalp bled. Several people can be seen laughing and eating during the attack, in addition to making disparaging remarks about President-elect Donald Trump and using racially charged language.
"It's sickening," Chicago Police Supt. Eddie Johnson told reporters Wednesday evening at a news conference. "It's makes you wonder what would make individuals treat somebody like that. I've been a cop for 28 years, and I've seen things that you shouldn't see in a lifetime, but it still amazes me how you still see things that you just shouldn't.
"I'm not going to say it shocked me, but it was sickening."
The incident took place Tuesday in an apartment on the 3400 block of West Lexington on Chicago's West Side, police said. Officers found the victim wandering the neighborhood in an obvious state of trauma, and soon authorities drew the connection with the disturbing Facebook video.
"You hear the narrative that police are backing down and not doing their jobs. This is a perfect example of them doing their jobs," Johnson said.
Four people -- two adult males and two adult females -- are now in custody, and criminal charges are expected. It's too soon to say whether the suspects would be charged with kidnapping or a hate crime, authorities said.
Three suspects are from Chicago, and a fourth is from northwest suburban Carpentersville.
"He is an acquaintance of one of these subjects," Chicago Police Cmdr. Kevin Duffin said of a connection between the victim and the suspects. "Apparently, they met out in the suburbs. These subjects then stole a van out in the suburbs and then brought him into Chicago."
The victim was treated and released from the hospital, police said. He is with his parents.
An investigation continues.
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