KOREATOWN (CBSLA.com) — A man has pleaded not guilty to attempted murder and committing a hate crime after being caught on camera attacking a woman with a hammer in a Koreatown strip mall, Los Angeles police announced Thursday at a news conference.

The rage unfolded around 6 p.m. Friday in the 1000 block of South Vermont Avenue.

Security video showed the victim was minding her own business on her cell phone, when a man walked past her, doubled back and stopped to talk to her. He asked her: “Are you Korean?” She replied yes.

He left and returned a few minutes later with a hammer and bashed her in the head with it at least 20 times as she struggled to cover her face and protect her head, the surveillance footage showed.

Karen Orellana worked just a few doors down from where the attack happened. She went outside when she heard the 24-year-old victim screaming.

By then, a security guard was there, and the suspect, Jae Won Yang, 22, put his hands up.

“I think they told him to drop the hammer, and then he just dropped it. But he was acting like nothing happened,” Orellana recalled.

A Good Samaritan also sprung into action, pinning the man down with his foot while he waited for police to arrive.

Another woman tended to the injured victim, who was covered in blood.

Police believed the suspect and victim did not know each other.

“Our investigation did reveal that our suspect had targeted this person because she’s a female, and she was Korean,” said Capt. David Kowalski of the LAPD.

He is a Korean national, homeless and recently came to the U.S., according to police.

The victim survived but suffered serious injuries.