Viral Video: Chicago Teen Knocks Out Homeless Man While Friends Laugh

The video is from April, but it's starting to go viral. And now it has officials scrambling to figure out who's involved.

The disturbing video surfaced on the site Worldstarhiphop.com over the weekend (link contains unedited language) and shows a teen's encounter with a homeless man at a Chicago train stop. In it, it's unclear what the homeless man is saying, but young people in the background can be heard referencing change. As the man waddles around, the teen can be seen wandering behind him, eventually asking the man a question. When the man turns to the teen, they exchange words. That's when the teen delivers a closed-fist punch to the side of the man's head, sending him to the ground immediately and appearing to render him unconscious.

But the most disturbing part of the video may be what happens after the punch: the teen's friends can be heard laughing and boasting about the incident as they board the train, and only one person rushes to the man's aid.

MyFoxChicago.com has the video:

The station reports on the attacker and what is being done:

FOX Chicago News spoke to the attacker's mother on Sunday. She refused to give her name, but admitted that it was her son in the video. She said he had been "going through some things" at the time of the attack. The mother had not seen the video until we showed it to her; his father saw it for the first time on Saturday.

A CTA sign flashing in the video indicates the attack happened in April 2011. FOX Chicago News contacted the CTA on Sunday; we were told that the agency had not heard of the attack until now, and investigators would look into it.

But according to the video report above, police say they will not get involved until the victim comes forward.

"Did you have a spiritually rejuvenating weekend during which your loving family members and random kindly strangers helped to restore some of your dwindling faith in humanity?" asks Gawker. "This video of a Chicago teenager punching an elderly homeless man should eliminate that new-found faith."

Or at least call us to restore honor and courage.