NEW YORK (CBSNewYork) – A woman walking with her 4-year-old son was brutally attacked in broad daylight Monday in Queens, police say.

Police said the 35-year-old victim and her child were on 84th Street in the Woodhaven neighborhood when they were approached by a man who demanded money.

The man punched the woman in the face, head, chest and back, knocking her unconscious, police said. He took her purse and took off heading west on 84th Street.

queens woman attacked while walking with son nypd Suspect Arrested After Woman Brutally Attacked In Broad Daylight While Walking With 4 Year Old Son

A woman walking with her 4-year-old son was brutally attacked in broad daylight Monday in Queens, police say. (Credit: NYPD)

Dramatic cell phone video shows 57-year-old suspect Derrick Chirse on the run after the vicious beating. David Williams shot the video from his apartment as the scene unfolded.

“It’s crazy, it’s ridiculous,” he said. “I don’t know why he’d do something like that, obviously he’s a punk.”

Police say Chirse took off with the victim’s bag and made his way into a backyard before trying to break into an apartment. A group of Good Samaritans, including Miguel Mojan, gave chase.

WEB EXTRA: See how neighbors confronted a Queens mother’s attacker

“I try to catch the guy (and said) ‘call the cops, call the cops, call the cops’,” he said.

Eventually a neighbor tried to stop and subdue Chirse with a stick .He then bolted up a nearby ladder, climbed up to the roof of a nearby CVS, and got away. Police say they arrested him nearby at a homeless shelter and charged him with robbery, assault, and endangering the welfare of a child.

The victim, who did not wish to appear on camera, says her son is traumatized by what happened.