The video showed a teenager being stomped by other teens as they laugh and record the assault. The victim's limp body is then lifted and pushed through a window as the teens continue laughing.
In a last scene of the video, the victim's face is shown with what appears to be blood, and his clothing is dirtied by the altercation.
The video was posted to Snapchat, a popular social media platform, and then became the subject of a petition on Change.org which garnered more than 28,000 online signatures.
WGRZ-TV reported that the Erie County Sheriff's Office was investigating the matter but cautioned that many of the rumors online about the assault were exaggerated or untrue. One claim was that the victim was left out in the woods to die, but that appeared to be false.
"There is an open investigation into an incident that occurred on Dec. 12 in Clarence," said the Erie County Sheriff's Office to WGRZ. "Deputies and crime scene unit detectives are working the case."
They went on to say that they had identified the victim and interviewed him and his family. They also photographed his injuries, saying "deputies can confirm that victim sustained an injury, sought medical treatment, and was released."
Clarence High School Principal Kenneth Smith acknowledged the incident in a post to Facebook but also cautioned against some of the rumors about the incident.
"Often, rumors spread via social media and become more distorted as the sharing increase. Remember that there are often changes to a story as it spreads," wrote Smith.
The disturbing video was being circulated on Twitter as of Wednesday with many unconfirmed rumors attached.
Here's a local news report about the harrowing incident:
Social media video leads to alleged assault investigation by the Erie County Sheriff's Officewww.youtube.com