Gunman who killed 5 in LI murder-suicide was son distraught over mother’s death, expected sale of home: neighbor

The gunman who carried out a five-person murder-suicide in a Long Island cul-de-sac Sunday was the adult son of the family’s matriarch who recently died — and could be heard “wailing [and] screaming” before he turned the gun on himself, according to police and a neighbor.

The alleged shooter was distraught over the passing of his 95-year-old mother, Theresa DeLucia, and the impending sale of the Syosset home where they both lived when he unleashed a bloodbath inside the small blue house on Wyoming Court, a neighbor told The Post and Nassau County’s top cop told a local news station.

“There were challenges. It’s really sad,” said Wendy Paisner, who lives across the street from the grisly scene. “But his mother passed away and I think that triggered him. You know, that they were selling the house.”

The son — who Paisner said had mental health issues — allegedly killed four victims inside the home and then went out to the front lawn and shot himself early Sunday afternoon, authorities said.

Paisner’s Ring camera caught the audio of the shooter killing himself on the lawn, calling the moment “very disturbing.” She turned it over to authorities while they canvassed the area.

“It’s real disturbing to hear. He was screaming, crying. The police have it,” she said.

“A wailing, screaming combination and then you hear the gun, then he’s wailing again, and that’s it.

“It was horrible. It’s really sad because I don’t know what kind of help he got for his [psychological issues] whatever it was. He definitely had some psych problems.”

A tree blocked the camera’s view of the gunman shooting himself, she noted.

Paisner, who has lived on the block for 30 years, went over to the home the day before to check on the man and his brother, who was visiting from out of town.

“He was sad. I said — ironically — I just said to him, ‘Things will get better.’ What can you say? He was distraught,” she told The Post. “He lived there all his life, so I’m just guessing the thought of him having to leave and his state of mind maybe [pushed him over the edge] … He was a petrified person.”

Investigators are probing whether the shooting was the result of a family dispute over the estate after DeLucia died last week, sources told The Post.

“It looks like someone wasn’t happy with the will,” a law enforcement source said.

Nassau County cops have yet to identify the dead shooter and the four slain victims, but Police Commissioner Patrick Ryder told News 12 that a man who lived in the home with his mother might have been upset over the expected sale of the house before he opened fire.

The four victims shot dead inside the home are believed to be family members, according to neighbors.

A local real estate agent, Mary Macaluso, told Newsday that the late matriarch’s kin contacted her to swing by the home Sunday in preparation for selling the property. When she arrived in the afternoon, police had already taped off the street.

The bodies were removed from the home shortly after 8 p.m.

The murder-suicide rocked the usually sleepy middle- to upper-class neighborhood filled with business owners, lawyers, doctors and mortgage bankers.

“It’s absolutely shocking. It’s shocking anywhere, but it doesn’t happen here that often, so we’re not really used to it,” said banker Corey Margulefsky, 49, who lives less than half a mile away.

“How does this happen? What drives people to do this? It sounds like a dispute over money … I guess somebody was cut out of the will,” he told The Post. “That is absolutely crazy for somebody to literally get rid of a whole family over money.”

Another neighbor, who didn’t want to give his name, said the mother and son who lived in the house where the massacre took place were largely isolated from others.

“I haven’t even seen them actually — very secluded,” said the elderly man, who has lived in the area for three decades. “They didn’t interact with anybody.”

But Paisner said the alleged shooter, who was a retired EMT worker, emerged as a helpful presence in recent years and did mechanical work for neighbors.

“He’s been friendlier in the past few years,” she said. “He wasn’t always extremely friendly, but my husband said he seemed to turn a corner and be helpful on the block.”