8-year-old boy killed, parents stabbed by knife-wielding family member shot dead by police in NYC nightmare

A knife-wielding maniac was killed by police Thursday after killing his 8-year-old brother and stabbing both of his parents in a Queens apartment, police said.

Police were called to an “extremely small” unit inside 147-25 94th Ave. in Jamaica just before 5:30 p.m. after the bleeding mother ran outside “begging for her life,” according to NYPD Chief John Chell.

Inside, officers found the 20-year-old man holding his father in a headlock over the kitchen sink with a knife to his throat, police and law enforcement sources said.

“They gave repeated commands, in English and Spanish, to drop the knife. He did not. A police officer fired a bullet, hitting the target, saving the man's life,” Chell said.

The family of four were rushed to hospital, where the boy and his murderous brother succumbed to their injuries.

The mother, aged 29, and the father, aged 43, are being treated for their injuries.

An 8-month-old baby who was also at home was spared unharmed by the bloodbath.

Police are still trying to determine whether the suspect and his young victim were brothers or half-brothers, or how the “tragic and horrific event” unfolded.

The investigation is ongoing.