A police officer fatally shot a 17-year-old boy just seconds after he fled from a traffic stop late Tuesday in a confrontation partly captured on video from a nearby home.

Investigators said Wednesday that the car stopped in the town of East Pittsburgh matched the description of a vehicle being sought in a nonfatal shooting in a town a few miles away. An East Pittsburgh officer, who has not been identified, was taking the driver into custody when the two passengers, including 17-year-old Antwon Rose, fled the car.

Allegheny County Police Superintendent Coleman McDonough said Rose was shot three times. A report from the medical examiner confirmed that Rose had died at a local hospital but did not say where he was struck or the cause of death. McDonough said police found two semi-automatic handguns on the floor of the car.

In the video, which was posted to Facebook, the teens can be seen dashing from the car. Three shots ring out, and both passengers appear to either duck or fall to the ground as they pass behind a house. A woman yells, asking why an officer shot the boy for running.

No shots were fired at the officers during the encounter, and no weapon was found on Rose's body, said McDonough.

There was no indication the other passenger from the car was shot or injured, but he was not captured and still was being sought by police, McDonough said.

Debra Jones told The Associated Press her voice is the one caught on the video.

Jones, 53, said she was sitting on the porch of the home she shares with her daughter when the traffic stop began. She said the officer drew his gun as he talked to the driver, and she instinctually took cover.

"I fell off my seat and started to crawl into my house. But I turned and said, 'No, someone needs to keep an eye on this,' and I came out to watch the stop," Jones said.

When the two passengers took off, "that officer didn't try to chase them or taze them. He just shot that boy for running," she said. "I looked out my kitchen window and they were putting him in handcuffs. He wasn't moving. I think that boy died right there on the side of my house."

McDonough noted there are circumstances when Pennsylvania law permits officers to use lethal force on a fleeing suspect. It's allowed to prevent death or serious injury to an officer or another person or if the fleeing suspect has used or threatened violence or possesses a lethal weapon.

County police were called in to conduct an independent investigation, which is standard procedure, McDonough said. He said the officer has been placed on administrative leave.

The driver of the vehicle, a 20-year-old man, was taken into custody and released after McDonough said officers did not feel they had cause to charge him in the earlier shooting.

The shooting in North Braddock happened less than 15 minutes before the traffic stop, McDonough said. He said a 22-year-old man had been shot in the abdomen after nine shots were fired from the car. The man, who was treated at a hospital and released, told police he fired back and struck the car.

McDonough said he was confident the car pulled over by East Pittsburgh was involved in the incident, noting that a back window had been shot out. He said it was too early in the investigation to say whether Rose had fired a weapon in the earlier incident.

The Pittsburgh Post-Gazette reported that Rose had been volunteering at the Free Store 15104 in Braddock each summer since 2015, according to founder Gisele Fetterman, the wife of Braddock Mayor John Fetterman.

"He was just a really lovely, gentle kid," Gisele Fetterman told the newspaper at a World Refugee Day event in Market Square on Wednesday. "His mom is amazing. All the kids loved him. Just a fine person. Bubbly. Funny. Goofy. Just really special."

Duquesne City Mayor Nickole Nesby, a friend of Antwon's mother who had known the teen since birth, described him as a well-mannered and smart person who liked playing basketball.

"He was a beautiful little boy," she told the Post-Gazette. "He was full of life."