Brooklyn man kills girlfriend -- then jumps to his death, NYPD says

A Brooklyn man with a history of domestic abuse knifed his girlfriend to death during an argument in the couple’s Sunset Park apartment early Friday, then leapt to his death, police said.

Dela Mateo, 61, was found fatally stabbed inside the fourth-floor unit that she shared with long-time companion Felix Santiago, 52, after neighbors called police to the building about 2:20 a.m. because of screams coming from behind the door.

When officers knocked, someone from inside yelled out: “Everything’s fine! The police aren’t needed!” police sources with knowledge of the case said.

The officers questioned more worried neighbors before going back to the apartment, the sources said. This time, no one answered their knocks.

After cops forced their way into the Sixth Ave. apartment near 53rd St. they found the woman sprawled out in the hallway of the apartment with multiple deep cuts to her head, neck and chest, police said.

A second pair of cops found her partner, Felix Santiago, 52, lying dead in the courtyard. He apparently jumped from the building after killing his girlfriend, but not before trying to clean up the crime scene, a police source said.

A bloody knife was recovered near Santiago’s body, police said.

Both victims died at the scene. Autopsies have been scheduled to fully determine how each person died.

It was not immediately disclosed what the two were fighting about — but the tensions started boiling over the night before, according to her close friend, Joyce Velazquez, who said Mateo called her at about 7:15 p.m. “screaming like crazy.”

“I told her to run for your life,” Velazquez said.

She later encouraged Mateo, who worked a factory job, to spend the night in her apartment but she refused.

“She said she was scared of him and stayed,” Velazquez said. “He used to say he was going to go to the roof and throw himself off.”

Velazquez also said she called 911 at that time but police said there is no record of such a call.

Police had been to the apartment several times between 2011 and 2015, police sources said. Cops had also been called to the apartment to quash arguments between the couple twice earlier this year.

In most of the cases, Santiago was accused of beating Mateo, sources said.

“He was beating her all the time,” Velazquez said, describing Santiago as 6 feet tall and husky. “She was very scared of him.”

The family has been struck by tragedy before.

On Feb. 27, 2011, their son Ian Santiago, 19, jumped from the same building and killed himself, police said.