'He just snapped:' Neighbors on Long Island murder-suicide that left 5 dead

SYOSSET, N.Y. (PIX11) – A man fatally shot his three siblings and niece before taking his own life in Syosset on Sunday, according to the Nassau County Police Department.

The shooting happened in a house on Wyoming Court just before noon. A neighbor apparently heard Joseph Delucia Jr., 59, yelling outside of the home he lived in with his mother before he shot himself, according to authorities.

"He just snapped, I think," Wendy Paisner, a longtime neighbor, previously told PIX11 News.

Delucia's mother passed away on Aug. 19. He was concerned he was left out of his mother's will and would be displaced, per police.

While Delucia wasn't cut out of the will, he would've had to leave the home, according to authorities.

"They were going to sell the house," Paisner said. "He's lived there his whole life. He really needed support."

Delucia's three siblings and niece were waiting at the house for a realtor, who showed up 30 minutes after the shooting, according to authorities.

Delucia had past mental health issues, per police. Police officers visited the home in 2022 for a welfare check.

Other neighbors told PIX11 News that Delucia was a volunteer firefighter who quit last week in the wake of his mother's death.

"I didn't think it was that he would take his whole family... I thought maybe he was distraught and maybe he did this to himself," Paisner said.