NEW YORK (CBSNewYork) — It was an unprovoked attack on two elderly women.

Surveillance video shows them walking down a street in Brooklyn when they’re assaulted with tremendous force.

Police said it was a homeless man who went on the rampage, CBS2’s Hazel Sanchez reports.

The women, who are both in their 70s, were casually walking on Pitkin Avenue in Brownsville. They never saw what was coming.

As the video shows, a homeless man approaches the woman pulling a shopping cart and shoves her to the ground. Her head smashing into the building. He then punched the other woman right behind her.

“It was bad. She was bleeding from her head and we had to give her tissue,” witness Jacaira Baez Mercedes said.

Within seconds, a Good Samaritan who had just passed by runs after the attacker and eventually tackles him to the ground and holds him as witnesses call police.

“He risked it all,” Mercedes said.

The shocking ordeal was captured by the surveillance camera outside Shoppers World on Pitkin Avenue, where employee Mercedes was walking in to work.

“I saw two men wrestling on the corner, and I was like they’re probably play fighting,” Mercedes said. “And when I came here I saw she was bleeding. She was asking for help in her language, and she didn’t know what to do.”

Once police arrived, the Good Samaritan, who is also homeless, rushed over to check on the two injured women and explained what happened to responding officers.

“We should have more people like him in the neighborhood because he actually saved her from getting more hurt. And he held the man down until the police came,” Mercedes said.

The homeless attacker, who is in his 60s, was arrested and is undergoing a psychiatric evaluation. The two injured women were treated at Brookdale Hospital and were released.

As for the Good Samaritan, CBS2’s Sanchez has learned he lost his cellphone during the altercation and it was not immediately known if he ever got it back.