An adult man with "mental health challenges," believed to be the victim in the video, was found disoriented and walking around on Chicago's West Side.
Police believe the victim was battered at a residence on West Lexington Street at 5:26pm Tuesday, where they found signs of a struggle and damage to property.
Later, police became aware of a "disturbing video" on Facebook Live, which shows an adult man being bound and beaten.
Police said this is the same man they found wandering around on Lexington Street. The victim is believed to have been held for between 24 and 48 hours. He was eventually unbound and let go, which is when police found him.
The victim, who is from northwest suburban Crystal Lake, was stable when he was transported to an area hospital, police said.
The victim's parents reported him missing Monday evening in northwest suburban Streamwood.
During the course of the investigation, the victim's parents received text messages from people who claimed to be holding their son captive, Streamwood police said.
Chicago Police Superintendent Eddie Johnson said four individuals were being interrogated Wednesday night. The offenders are described as two women and two men, all around 18 years old.
Three of the offenders are believed to be Chicago residents, and one is believed to be from the suburbs of Chicago, police said.
The victim is an acquaintance of one of the offenders, and is believed to have initially gone with the offenders willingly. It is unclear if the victim knew the other three offenders, police said. null