MY KILLER SON IS ‘CRAZY’

Only God knows how hammer-slay susp got that way

The mother of a hammerwielding man who killed two Asian restaurant workers and left another clinging to life says her son's mental illness came on suddenly — and she can't explain it.

“He's a crazy person — that's it,” Svetlana Chalmers, 57, told the Daily News. “I don't know how he got that way. Nobody knows. Only God knows.”

The estranged mother of Arthur Martunovich, 34, a construction foreman who remains under psychiatric evaluation after the attack, said her son was a “normal person” when she moved from Brooklyn to Pennsylvania a year ago.

“He was an adult,” Chalmers said. “He was a normal man with his own life. I don't know how he did this.”

Martunovich burst into the Seafood Buffet on the Sheepshead Bay, Brooklyn, waterfront Tuesday afternoon and bludgeoned three workers with a hammer.

Chef Fufai Pun, 34, died shortly after the attack. The restaurant's owner, Kheong Ng-Thang, 61, died of his injuries Friday.

Tsz Mat Pung, 50, a manager at the restaurant, remains in critical condition at NYU Langone Hospital-Brooklyn with massive head injuries.

Martunovich said that he was hunting Asians, according to a witness. “I don't have a problem with the Hispanics, but with the Chinese,” he allegedly told Francisco Sales, a dishwasher at the restaurant.

Martunovich's distressed mother said her son never harbored any racial hatred before.

“He never had anything against Asians or anybody,” Chalmers said. “He's lost his mind.”

Cops nabbed Martunovich about two blocks from the restaurant. Police found a hammer at the bloody scene. Martunovich lived in Brighton Beach, six blocks from the eatery.

This is Martunovich's first arrest. He was accused of assault in 2016, but never charged, said police. Sources said he was an assault victim in 2004 and 2016, and no one was arrested in either incident.

“This is a tragedy for everybody involved,” said Chalmers. “A tragedy for the people he killed, their families, even my husband and myself.”

“Nothing you can do will bring any of these people back,” she said.

“I can't look people in their eyes,” Chalmers said. “It's affected so many lives. It's terrible.”

Svetlana Chalmers (l. inset) says her son Arthur Martunovich (above) had recently taken a sudden turn toward madness.

Arthur Martunovich (above) is taken for psychological tests after savage attack in Brooklyn restaurant. His mother, Svetlana Chalmers (below), could not fathom what would make her son do such a thing. “He was a normal man...I don’t know how he did this,” she said.