A 20-year-old woman was brutally murdered—her head nearly-decapitated and her fingers severed—following an attack inside a Brooklyn apartment Saturday, a senior NYPD official told The Daily Beast.

A second woman was critically injured and a 4-year-old girl was found unharmed in a back bedroom of the apartment, the official said.

A person of interest was arrested in connection with the killing Saturday night and was being questioned, NYPD Deputy Chief Michael Kemper said during a press conference. Kemper would not go into details about the suspect, but said that the man is known to both women and police are “confident that we’re not looking for anyone else right now” in connection with the attack.

“We believe this incident was not random,” Kemper said. “We believe the victims knew their assailant.”

A second law enforcement official told The Daily Beast the man is the boyfriend of the woman who survived the attack.

Investigators are working to determine if a bloody axe that was recovered from a nearby dumpster is the weapon used to kill the victim, Savannah Rivera, police said.

The incident took place around 1:30 a.m. inside a housing project in Brooklyn’s increasingly hip Bushwick neighborhood.

According to a preliminary investigation, officers responded to the scene when the second woman escaped the attack, flagged down a taxi cab and asked the driver to take her to a hospital, police said.

The driver, noticing the woman was severely injured and bleeding, called 911. Responding medics took the woman to the hospital because of her condition before officers arrived, the senior law enforcement official said.

On her way to the hospital the woman told medics that there was a dead woman inside the building and that a 4-year-old child was also in the apartment, the official said.

Responding officers and medics found Rivera, unconscious and unresponsive in the living room of an eighth-floor apartment with stab wounds and cuts to her head and body, police said. She was pronounced dead at the scene by responding medics.

Police found the 4-year-old daughter of the injured woman unharmed in a back bedroom of the apartment, police said. She has been taken to an area hospital for observation.

The girl’s mother remains in critical but stable condition with lacerations on her head and body, police said.

Officers at the scene say Rivera was fully clothed in the blood-splattered living room of the apartment, the official said. Police believe she was visiting the 21-year-old woman, who is believed to be a family member or friend, when the attack took place, and does not live in the building.

No arrests have been made, but officers found an axe in the trash compactor of the apartment, the official said. Forensic tests are being done to determine if it is the murder weapon.

Investigators have determined that there is surveillance camera footage in and around the building and are working to secure and analyze the video to determine who may have entered or exited the building, the official said.

The police had previously responded to a dispute between the surviving 21-year-old woman and her mother, the official said, adding that the mother was not home at the time of the murder.

— With reporting from Audrey McNamara