Video released by the police is disturbing to watch.
It shows the attacker hit the 28-year-old victim over the head with a cobblestone.
It happened on Wednesday, June 9 at 4:55 a.m. on Brook Avenue in Mott Haven.
Police say the suspect stomped on and kicked the victim, before grabbing another cobblestone and hitting him with it.
The victim was taken to Lincoln Hospital with severe head injuries in critical condition.
The attacker fled on foot eastbound on East 147 Street.
A woman walking by discovered the victim a short time later and called 911.
Anyone with information in regard to this incident is asked to call the NYPD’s Crime Stoppers Hotline at 1-800-577-TIPS (8477) or for Spanish, 1-888-57-PISTA (74782).