Investigators are looking for the unhinged man who severely beat an elderly man in an attack that was caught on video, police said.

Wilfredo Arce, 62, was inside the lobby of a NYCHA building at 77 Tompkins Ave in Bedford-Stuyvesant on Friday around 6:15 p.m. when he was attacked by Lytee Knox Hundley, police said.

Video of the attack, which was posted to social media, shows Hundley approach Arce and punch him, knocking him to the ground.

As the downed man holds his hand out, Hundley is seen repeatedly punching and kicking him in his head and face — as most bystanders look on, and can even be heard laughing.

“Brutal attack on an elderly male. Our communities will not stand for this and neither will the #NYPD @NYPDHousing @NYCHA,” NYPD Chief of Detectives Dermot Sheet wrote on Twitter. “See him? call 911. Know him and his current whereabouts? Call @NYPDTips 800-577-TIPS (8477) #Brooklyn #YourCityYourCall #sharedresponsibility @NYPD79Pct.”

Police are now fervently looking for Hundley, who left the building following the attack.

The victim was rushed to Woodhull Hospital with non-life threatening injuries that included a broken nose and a broken orbital bone.