An elderly Queens man allegedly murdered his daughter-in-law by stabbing her multiples times in the neck, authorities said Thursday.

Police responding to a call of an assault in progress in Ridgewood around 8:30 a.m. on March 28 were waved down by a pedestrian who led them to the rear entrance of 1742 Suydam St. — where cops say they saw 76-year-old Dahe Lin on top of his daughter-in-law, Wen Ying He, and a knife lying near her body.

Police pulled Lin off the unconscious, bloodied victim and provided aid until medics arrived.

A woman who told the Post she witnessed much of the fatal encounter, said when she came home she saw Lin on top of He, strangling the woman before he stabbed her.

“She’s not moving anymore… she’s not moving anymore,” a 37-year-old woman recalled hearing Lin repeatedly say.

She and another neighbor ran over and kicked Lin, forcing him off the woman.

But Lin then ran inside, grabbed what she called a “giant kitchen knife” and started stabbing his daughter-in-law, she said.

“When that happened, I screamed really, really loudly at the top of my lungs,” she told the Post. “He barely looked at us even though we were right there.”

He, 50, suffered several stab wounds in the neck and was rushed to Wyckoff Hospital, where she died on Sunday, cops said.

Lin, who suffered a cut on his face during the incident, was arrested immediately by police and was charged two days later with murder and criminal possession of a weapon.

It wasn’t immediately clear what caused the outburst.