Video shows Steve Buscemi’s alleged attacker talking to himself moments before he randomly slugged actor in NYC

The man suspected of sucker-punching actor Steve Buscemi in Kips Bay last week appeared to be talking to himself while walking down the street moments before the random attack, according to new video footage.

The clip obtained by The Post shows the suspect muttering to himself and waving his arms while walking north on Third Avenue just moments before he allegedly slugged the 66-year-old “Boardwalk Empire” star.

Buscemi, a New York native, was photographed with a black eye and bruised chin in his first appearance since Wednesday’s broad daylight assault.

The deranged man walked up to the actor and promptly punched him in the face in an unprovoked attack, police said.

“The guy just came up to him and punched him on the side of the head for no reason,” said a worker at a nearby building who saw the whole thing play out on surveillance footage. “[Buscemi] didn’t see anything. He went straight to the ground and the guy kept going.

“[Buscemi] got right back up with an expression like, ‘What just happened?’ and looked toward the guy who’d hit him,” the worker said. “The guy shouted something back at him and kept going.”

He said the Kips Bay neighborhood “is full of people like this and it’s just getting worse.

“Everybody has to look over their shoulder now,” he added. “And no one with the power to do anything wants to stop what’s going on.”

Cops released photos of the Brooklyn-born actor’s alleged attacker last week as he remains out roaming the streets.

Buscemi, who was a New York City firefighter before launching his movie career, is doing OK, according to his agent.

“Steve Buscemi was assaulted in Mid-Town Manhattan, another victim of a random act of violence in the city,” the actor’s publicist said in a statement Sunday. “He is OK and appreciates everyone’s well wishes, though incredibly sad for everyone that this has happened to while also walking the streets of New York.”

Buscemi, who has starred in hits like “Fargo,” “Reservoir Dogs” and “The Big Lebowski,” is shockingly the second cast member of the hit HBO series “Boardwalk Empire” to be randomly attacked in the city.

On March 31, actor Michael Stuhbarg was jogging on the Upper East Side when a vagrant slammed him with a rock.