 -- The police shooting of a stabbing suspect at the Brooklyn headquarters of an Orthodox Jewish sect early this morning "looks like it was justified," New York Police Commissioner William Bratton said.

An officer with seven years on the force shot and killed Calvin Peters, 49, after police "gave verbal commands for the male to drop the knife," Bratton said.

The incident happened about 1:45 a.m. inside the headquarters of Chabad-Lubavitch. Peters walked into the facility asking for a book, police said. He then stabbed a 22-year-old student from Israel in the side of the head with a nine-inch knife, they added.

Witnesses said the man was repeating, "Kill all Jews," as he stabbed the student, according to an emailed statement from Rabbi Motti Seligson of Chabad-Lubavitch -- though Bratton later said reports the suspect uttered an anti-Semitic phrase were unverified.

Bratton said that Officer Timothy Donohue, 25, was stationed in a police command post outside the building when one of the witnesses ran outside to alert him of the attack.

When officers arrived, Officers Roberto Pagan and Kevin Hanna ordered Peters to drop the knife, police said. He placed it on a table, but then picked it up and walked toward some of the officers, officials added.

Pagan, 29 and seven year veteran of the force, shot Peters.

Bratton called the officers’ actions “more than justified."

Cell phone video captured the incident. It showed officers yelling at a man and captured the sound of the single gunshot.

Peters was taken to Kings County Hospital, where he died.

Seligson identified the stabbed student as Levi Rosenblat. Mayor Bill de Blasio said Rosenblat is in serious but stable condition at Bellevue Hospital.

"While we are very pained by everything that has unfolded, we are very grateful to the police for their quick response and are working closely with the authorities in their ongoing investigation," Seligson said in his emailed statement. "We commend the heroic efforts of the individuals who were present and took immediate action, if not for their intervention the outcome could have been, G-d forbid, far worse. We continue to pray for the young man who is in stable condition."

Police were confident the incident was not terrorism but rather the work of someone with a history of being an emotionally disturbed person.

However, Deputy Commissioner John Miller said, "concern that the news of this story might bring [attention] to houses of worship around the city" means some extra patrols around synagogues.

Peters had a history of bi-polar disorder, according to Jeffrey A. St. Clair, an attorney who opened the door to the Peters family home in Valley Stream, New York, The Associated Press reported.

"Calvin Peters was a loving and devoted father," St. Clair told the AP. "And the family is quite frankly shocked and disappointed at what happened. Our prayers go out to the person that was injured. But we really ask that you respect our privacy and allow them to grieve."

The mayor responded to the incident with a call for enhanced mental health resources for those in need, a vow to investigate the incident, and initial praise for the police response.

"While any loss of life is tragic, we are fortunate that, thanks to the actions of our officers early this morning, more people were not injured or worse," de Blasio said in a prepared statement.

Bratton said the department is considering a significant expansion of the taser program.

ABC News' Mark Crudele and Michael S. James contributed to this report.