The García family was in their Olney living room early Wednesday morning, watching 2-year-old Danya open her Christmas presents. Then they heard the screams next door. Eréndira García, 37, stood up, walked past the family’s Christmas tree, and peeked through the blinds.

She saw a man pulling a woman under a red van, and a lot of blood. She and her 19-year-old daughter, Maria García, then looked through the glass of their front door into the neighboring house. They saw blood on the stairs and carpet, and children screaming and crying.

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The Garcías called police, and officers arrived on the 5600 block of North Mascher Street within minutes. There, shortly before 3:30 a.m., police said, they found a 35-year-old woman outside, bleeding heavily from the abdomen, and her 33-year-old boyfriend standing over her.

On the second floor of the two-story rowhouse, officers found her 14-year-old son with a stab wound to his right thigh. Police also found a blood-soaked butcher knife with a 10-inch blade, an apparent stabbing weapon.

The woman was taken to Einstein Medical Center Philadelphia, where she was pronounced dead at 3:36 a.m. Her son also was taken to Einstein, where he was in critical condition, police said.

The man, who was taken into custody, cut his own hands during the violent spree and was to be treated at the hospital before being transferred to the Homicide Division, Philadelphia Police Chief Inspector Scott Small said. No charges had been filed as of late Wednesday afternoon.

“Heartbroken by what appears to be an act of intimate partner violence that has robbed several children of their mother,” Philadelphia District Attorney Larry Krasner tweeted Wednesday morning.

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The violence erupted during a family party inside the Olney home, where the 33-year-old man — whom police had not identified as of late Wednesday afternoon — was “drinking heavily and started arguing and fighting with other guests at the party,” police said in a news release, citing a preliminary investigation.

He “eventually turned his rage” toward his girlfriend and her 14-year-old son, police said.

When he grabbed a knife from the kitchen and the teenager tried to stop him, he stabbed the teen in the right thigh, police said. He then got another knife, stabbed his girlfriend, and chased her outside, where he continued to stab her and where police found her.

In addition to the 14-year-old, five other children ranging in age from 8 to 16 were in the house, Small said.

The children inside the home told police the man had stabbed the woman, Small said. Police said they believe that the couple and children all lived in the home and were related “in some way,” Small said.

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“The juveniles that were inside the property,” Small said at a news conference, “we believe all of them witnessed the incident or at least part of the incident.”

Inside the home, police found evidence of a “violent struggle,” Small said, with broken glass, overturned and broken furniture, and blood on the first floor, the stairs, and the second floor.

The street in front of the home was still blood-stained Wednesday afternoon, with blood drops scattered on the sidewalk across five properties. A snowman hung from the front door knob, and a wreath was on the blood-stained white door.

A string of Christmas lights in the window was still glowing.