Police say they've arrested the man captured on shocking surveillance video sucker-punching a 64-year-old Queens man last summer, killing him.

Mathew Smith, 42, of Queens, was arrested Monday on charges of criminally negligent homicide and assault with intent to cause physical injury, the NYPD said.

It's not clear if Smith had an attorney.

Video shows the suspect punching Patrick Gorman in his head at the corner of Main Street and Queens Boulevard in Briarwood just after midnight on June 26. The man falls to the ground but gets back up for a moment before collapsing again.

The victim ultimately died at Jamaica Hospital.

Police say Gorman may have brushed up against a woman Smith was with, starting a fight with Smith.