The authorities in France have opened a criminal investigation after a 17-year-old driver was shot and killed by a police officer during a traffic stop near Paris, an episode that touched off a night of violence and fueled a longstanding debate on the use of deadly force by the country’s security forces.
Initial news reports, based on what were described as anonymous police sources, had suggested that the driver had plowed into two officers with his car on Tuesday during the stop in Nanterre, west of the capital. But an unconfirmed video of the shooting that appeared later led to accusations that the police had acted too aggressively, and prosecutors in Nanterre have opened a manslaughter investigation.
The video, believed to have been filmed by a witness, spread quickly on social networks and was picked up by the French news media. It shows two helmeted police officers on the left-hand side of a yellow car that is stopped on the street. The video was also obtained by The New York Times from a person who said she was close to the witness and who spoke on the condition of anonymity out of fear of repercussions for sharing the footage.
The officers, both peering into the driver’s window, are heard shouting, although what they said to the victim, identified by lawyers for his family as Naël M., was unclear. One of the officers leans onto the windshield and points what appears to be a firearm at the driver, and as the car starts moving away, a loud bang is audible.
That officer is in police custody, though he has not been charged, and the family of the driver said that it was going to file a complaint accusing the police officer of murder.
On Wednesday, Emmanuel Macron, the French president, expressed “the nation’s sympathy” for the teenager’s family. “Justice must be done,” Mr. Macron told reporters in Marseille, in southern France. “Nothing justifies the death of a young person,” he said, adding: “What we all want is calm.”
Gérald Darmanin, the French interior minister, told reporters in Paris on Wednesday, “We have all seen these extremely shocking images.”
“When a young man dies in conditions like these, emotion is normal,” Mr. Darmanin added.
Mr. Darmanin said that the police officer would be punished if warranted. “An act like the one that we saw, if the investigation confirms the videos that we have seen, is never justified,” he said. The two officers are experienced members of the traffic police in their late 30s and early 40s, and had no record of misconduct, Mr. Darmanin added.
The shooting quickly inflamed long-simmering anger in suburbs where relations between the police and residents are often fraught with mistrust. On Tuesday that rage quickly spilled into violence, especially in the Hauts-de-Seine area, which includes Nanterre.
More than 30 people were arrested overnight, according to the French authorities, after protesters threw rocks and fireworks at riot police, who responded with tear gas. Protesters also burned some 40 cars and set fire to construction shacks and some buildings. A city hall annex in Mantes-la-Jolie, a town further west of Paris, was entirely destroyed.
Mr. Darmanin said that 2,000 police officers and gendarmes would be deployed across France on Wednesday evening to contain unrest.
The prosecutor’s office in Nanterre said in a statement on Tuesday that the shooting occurred on Tuesday morning, between 8:15 and 8:20, near Place Nelson Mandela, a square in Nanterre not far from La Défense, a business district northwest of Paris.
Two people were in the vehicle in addition to the driver, the prosecutor’s office said: One of them was released after questioning by the police; the other was still being sought by the authorities after fleeing the scene.
Laurent Nuñez, the Paris police prefect, told the French TV channel CNews on Wednesday that the two officers had tried to stop the car because the driver had committed several traffic violations and had refused to stop a first time, before getting stuck in traffic. That is when the two police officers were able to approach the vehicle, he said.
Mr. Nuñez said an investigation would determine the circumstances of the incident.
“It isn’t normal to die during a traffic stop when you are 17,” Mr. Nuñez noted.
The driver died an hour after being shot, the prosecutor’s office said. An autopsy was expected on Wednesday, but initial tests did not indicate that the driver had been under the influence of any drug or alcohol, the prosecutor’s office said.
Yassine Bouzrou, a lawyer for the family of the driver, said that in addition to the complaint against the police officer who fired the shot, the family would also file a suit accusing the other officer of complicity in what they called a murder and another legal action accusing the officers of lying about the incident in their initial statements.
Deadly firearm deaths are uncommon in France, but the shooting on Tuesday quickly captured the nation’s attention, including celebrities.
The actor Omar Sy and the soccer player Kylian Mbappé both expressed support for Naël’s family on social media.
“My France hurts,” Mr. Mbappé wrote on Twitter, calling the incident an “unacceptable situation.”
Constant Méheut contributed reporting.