The NYPD says a gunman ambushed and killed an officer in what the city's police commissioner called a "clear assassination" before backup arrived and shot the attacker dead.

NYPD Sgt. Brendan Ryan says the victim, 48-year-old Miosotis Familia, died at a hospital early Wednesday. She had a gunshot wound to the head after the attacker fired into her vehicle through a window, police say.

Familia had been on the force for 12 years and was a mother of three.

Police say other officers shot and killed the suspect, who was brandishing a revolver. A stray bullet also struck another person, believed to be a bystander, who is in stable condition.

The attack happened in the Bronx's Fordham Heights neighborhood around 12:30 a.m., while Familia was sitting in her vehicle, a mobile command unit. She and her partner had been stationed there after a rash of crimes in the neighborhood, including a taxi shooting in March that left three people hurt on the Grand Concourse.

Recordings of the radio call show Familia's partner screaming for backup and an ambulance.

Other officers spotted the suspect, 34-year-old Alexander Bonds, running about a block from the scene of the ambush, police say. He died in a gunfight with those officers.

Bonds had a criminal record including six prior arrests. He was on parole for a 2014 robbery upstate in Syracuse.

Police say Bonds had posted an anti-police video on his Facebook page last September, in which he complained about police officers killing and abusing people. In the video, he ominously warned that if police didn't leave him alone, "We gonna do something."

"A coward went up to a woman who was doing her job on the holiday, was in plain clothes and assassinated her," said Nassau PBA President James McDermott. "Now you have three children without a mother (and) a 48-year-old woman, her life cut short."

Familia's slaying is reminiscent of the 2014 shooting deaths of NYPD Detectives Rafael Ramos and Wenjian Liu, who were similarly gunned down as they sat in a marked police car in Bedford-Stuyvesant in Brooklyn. And it also struck nerves in North Massapequa, the hometown of another member of the NYPD gunned down in the line of duty, Brian Moore.

"You see all of the blue ribbons on all of the houses?" asked Albert Pelliccia, a retired NYPD transit officer who was wounded in the line of duty himself. "This is a police community, and what happened to Brian Moore was devastating."

He also called Officer Familia's death an assassination, and said it is a stark reminder of the risks that come with the responsibility of wearing that badge.

"You take an oath to serve and protect," Pelliccia said. "But then there's nobody to protect you."