By Alison Fox and Joe Jackson

UPDATED | A Chinese immigrant was arrested Sunday and charged in the stabbing deaths of a mother and her four children inside a Brooklyn home, officials said.

Mingdong Chen, 25 years old, faces five counts of murder in the attacks on his relatives, allegedly carried out with a butcher knife inside a Sunset Park home late Saturday, police said.

"It's just a scene you will never forget," said NYPD Chief of Department Philip Banks, calling the attacks "an unspeakable act."

Mr. Chen, who is a cousin of the victims, is awaiting arraignment and could not be reached for comment. It was unclear if he had retained a lawyer.