Police said Derrick Chirse, of Brooklyn, faces several charges after a 35-year-old mother was punched in the face, head, chest and back in front of her child Monday.
She had been picking her son up from his pre-school on Atlantic Avenue and 84th Street in Woodhaven.
The mother was knocked unconscious, and the 57-year-old suspect allegedly stole her purse and ran away.
Good Samaritans chased him into a nearby backyard but he jumped over three fences before he managed to climb onto the roof of a nearby CVS and escape.
Eyewitness News spoke to a witness who tried to smack the suspect with a chair.
"I hit him with the chair, but he threw it back at me again," said Khaled Elshabasy. "And he ran away from here up and ran away, I don't know."
When the chair was unsuccessful, Elshabasy said he tried again with a broom, but the suspect still got away.
The victim suffered bruising and swelling to her face and body. She was treated and released from a nearby hospital. The 4-year-old boy was unharmed.
* More Queens news
* Send us a news tip
* Download the abc7NY app for breaking news alerts
* Follow us on YouTube