Chicago police are examining a video and interviewing witnesses to try to find out who was among a gang of young people who attacked and stabbed a 25-year-old man in the Lakeview neighborhood late Sunday.



The man, who was being treated at Advocate Illinois Masonic Medical Center, was attacked in the 3300 block of North Halsted Street following a confrontation with a group of young people about 11:45 p.m. Sunday, according to police. Although police News Affairs said the man was taken to the hospital in good condition, another police report said he initially was in serious condition.



Part of the attack was captured on video by witnesses who said they had a video camera handy because of recent attacks in the 3300-3400 blocks of North Halsted.



Witnesses told police that the group was walking south on Halsted when they began yelling and got into a confrontation with the 25-year-old, who was stabbed multiple times, according to a police report. No one was in custody, but Belmont Area detectives were interviewing the victim and witnesses and reviewing videos post on the Web that captured part of the incident, as well as its aftermath.



John Cunningham, 34, and his partner, Rob Sall, 31, live in the area, saw the confrontation and shot video of much of the incident. They and others in Lakeview have been on alert in recent weeks following a stabbing June 18 in the 3400 block of North Halsted Street in a 7-Eleven parking lot and another attack nearby a week ago, Cunningham and Sall said.



Late last night, Cunningham and Sall saw about 20 people walking south on the Halsted, while two people walked north. Someone spilled someone else's drink or jostled someone, and when the two groups passed, one of the men in the smaller group turned around and said something to someone in the larger group, Cunningham said.



Words were exchanged between the 25-year-old and someone in the larger group, and then the two groups came back together, Cunningham said.



"At first, it seemed like they knew each other," and the exchange of words was just posturing, Cunningham said.



But then, the 25-year-old, who was wearing orange shorts, was pushed up against a fence, and then down onto the ground, Cunningham said. That's the point at which Sall started shooting the video, which he subsequently posted on YouTube.



The video, which lasts about 1 minute, 49 seconds, shows a group of about 10 to 15 young people apparently punching and kicking someone who appears to be on the sidewalk on the west side of Halsted Street. The victim, who is only partially visible in the first part of the video, then disappears off-screen. Most of the people who had been participating in the beating run after the person.



Police have not released detailed descriptions of the attacker or attackers who stabbed the man.



Cunningham said the victim is a young man who soon after appears on the video, running across the street and hitting the wall of a building. At the end of the video, he can be seen holding his side briefly.



After the video was shot and police were called, Cunningham was able to get a closer look at the victim, who he said was stabbed at least twice in the chest, with a deep cut on his right chest and a puncture wound on the right side of his chest.



Several people were calling 911 as the fight went on, but "none of us realized he had been stabbed when we first called," Sall said.



Recent conflicts involving young people on the street in the part of Lakeview known as Boystown have led to the creation of aFacebook group, "Take Back Boystown," as well as a gathering in the 7-Eleven parking lot Saturday night that tried to bring police and residents together.



"It's an entertainment district, there are going to be people on the street," Sall said. But people in the area believe "there has been a rise in violent crimes" involving large groups of people recently.



lford@tribune.com