Https://www.nhregister.com/news/article/4-arrested-in-January-beating-of-New-Haven-man-11532952.php
They even post the location and Google Maps confirms it's where the video was recorded
The beating took place hours after Damien Blandina, 31, working underneath a car near Chapel Street and Ellsworth Avenue, was crushed when the jacks slipped from under the car.
https://www.google.com/maps/@41.3127441,-72.950798,0a,90y,245.75h,91.18t
The victim here is Mathew Turner and was arrested 6 years later on child pornography and sexually assaulting a 6 year old. The mugshot shows it's the same guy from the video.
This video isn't the assault that left him "unrecognizable". That happened later.
A rumor had spread that police had arrested the neighbor, then released him.
After police released him from questioning, the Good Samaritan neighbor walked up to Blandin’s friends at a makeshift memorial at the site of the death. He tried to explain what had happened. They warned him to leave.
This video is them warning him to leave. But what happened after was:
Blandin’s widow followed the neighbor into the hallways of New Jack City.
A video inside the New Jack City hallway shows Blandin’s widow stopping the neighbor. “Seconds later, a mob” of nine men “ran into the apartment building into the stairwell … one in possession of a gun.” The soon-to-be attackers were black; the victim, white. (The warrant is for the arrest of the man with the gun on burglary, assault, and weapons charges.)
https://www.newhavenindependent.org/article/violent_mob_smashes_surveillance_cam_at_new_jack_city
TL;DR: Somebody got crushed under his car near the site of the video days before. White guy in video was questioned by cops and released. He goes to site to explain to the family what happened. That's the reddit video. He leaves, but is followed later to his apartment around the block and beaten.
Same guy is arrested years later for child porn and raping a 6 year old.
There are no winners in this story.