BROOKLYN CENTER, Minn. — The officer who fatally shot a Black man during a traffic stop near Minneapolis wrongly confused her gun for her Taser, police officials said on Monday, quickly releasing video as they attempted to ease tensions in a country on edge across the Derek Chauvin trial.

In a brief clip of body camera video, officers from the Brooklyn Center Police Department can be seen trying to handcuff the driver, Daunte Wright, until he abruptly lurches back into his car. One of those officers aims a weapon at Mr. Wright and shouts, “Taser! Taser! Taser! ”

She fires one round, and Mr. Wright groans in pain.

Holy shit, I just shot him, the officer can be heard shouting.

Late Monday, the officer who fired the fatal shot was identified as Kim Potter, who has worked for the department for 26 years.

The statement came as protesters faced off with the police . Hundreds had gathered outside the Brooklyn Center police station for the second consecutive night, defying a new 7 p.m. curfew in a steady rain.

Daunte Wright with his son. Credit…Ben Crump Law

Demonstrators sometimes lobbed water bottles and stones over newly erected fencing, chanting “killer cop” and “ palms, don’t shoot” while officers clad in riot gear stood guard. Officers responded by sporadically firing projectiles at the audience and at one stage released a chemical agent that caused people to start coughing.

Mayor Mike Elliott of Brooklyn Center, in an interview on CNN, urged the protesters to leave: “I’m asking everybody to go home. We will need to keep the peace in our city. ” By midnight, just a few dozen people remained.

The deadly shooting on Sunday took place in a region already at the center of a national reckoning over police officers’ use of force against Black folks. Since the investigation into Mr. Wright’s death in Brooklyn Center was beginning on Monday, prosecutors in a courtroom less than 10 miles away finished the questioning of the witnesses in the trial of Mr. Chauvin, the former Minneapolis police officer charged with murdering George Floyd last May.

The Twin Cities had spent the afternoon bracing for unrest. The mayors of Minneapolis and St. Paul declared states of emergency, and professional baseball, basketball and baseball games in Minnesota were postponed.

The shooting of Mr. Wright, 20, whose autopsy revealed he was shot once in the chest, caused an immediate outcry throughout the country, protests and looting in Brooklyn Center, and recognition by President Biden, who said he was praying for the Wright family and called for an investigation.

We do understand that the anger, pain and injury amidst the Black community are real, Mr. Biden said at the White House.

He also said: “In the meantime, I want to make it clear again: There’s absolutely no justification — none — for looting. No justification for violence. Peaceful protest? Understandable. ”

Gov. Tim Walz, a Democrat, angrily demanded that state lawmakers pass police reform that has languished since Mr. Floyd’s death . He said he was going right from the news conference to the Capitol in St. Paul.

Our time was made clear last May in Minnesota, Mr. Walz said, alluding to the death of Mr. Floyd. “Our time to get one shot at fixing it was there. And in the midst of this trial that the world’s viewing, the situation repeated itself yesterday. ”

The deadly police shooting comes at a particularly fraught moment.

Everyone in the metro area is on tenterhooks right now, said Abigail Cerra, a Minneapolis civil rights lawyer and a member of the Minneapolis Police Conduct Oversight Commission, noting that her husband, a firefighter, is among the many emergency workers throughout the area who have been told to keep their gear with them at all times as the trial proceeds.

She questioned why Mr. Wright who the authorities said was stopped for driving a vehicle with an expired registration could have have been pulled over at all. Everyone is on high alert right now, she said. “I don’t understand why they would be making traffic stops such as this at this moment in time. ”

The police said officers tried to detain him after they found that there was a warrant for his arrest, stemming from a hearing on a misdemeanor gun charge.

Mr. Wright was facing two misdemeanor charges after Minneapolis police said he’d carried a pistol without a permit and had run away from officers last June. Katie Wright told me that her son had been driving a car his family had given him two weeks ago and that he had called her as he was being dragged over.

He said they pulled him over because he’d air fresheners hanging from his rearview mirror,” she said. Ms. Wright added that her son had been driving with his girlfriend when he was taken. The authorities said a woman in the car had been hurt in a crash which happened as the vehicle kept moving after the shooting.

Chief Tim Gannon of the Brooklyn Center Police Department said in a news conference that it would utilize the body camera video of the shooting to ascertain whether Officer Potter would remain on the force.

“ It is my belief that the officer had the intention to deploy their Taser, but rather shot Mr. Wright with a single bullet,” he said.

Mike Elliott, the mayor of Brooklyn Center, urged calm in the city and promised that an investigation would be conducted by the Bureau of Criminal Apprehension, a state agency that investigates police killings in Minnesota.

“We realize that this couldn’t have happened at a worse time,” said Mr. Elliott, the city ’s first Black mayor. “We recognize that this is occurring at a time when our community, when all of America — really, all the world — is watching our community. ”

The racial makeup of the suburb, home to 30,000 inhabitants, was until recently mostly white, but now less than half of residents are white and almost a third are Black.

Mr. Elliott, who has been mayor for two decades, called for the officer who shot Mr. Wright to be fired. My position is that we can’t afford to make mistakes that cause the loss of life of other individuals in our profession, ” he said. “And so I do fully support releasing the officer of her duties. ”

Minnesota has seen more than its share of high-profile police killings, including the shootings of Philando Castile in 2016 and Jamar Clark in 2015, and the death last year of Mr. Floyd.

In the final day of the prosecution’s case against Mr. Chauvin, Mr. Floyd’s brother Philonise Floyd took the stand, telling of their upbringing in Houston. George would help his sisters get dressed for school and made the best banana mayonnaise sandwiches, his brother said. “George couldn’t cook, but he’ll make sure that you have a snack or something. ”

The state also called two expert witnesses, a cardiologist who said Mr. Floyds death was completely preventable, and a policing expert who said a reasonable officer wouldn’t have put Mr. Floyd facedown since he was in handcuffs and wasn’t a threat.

In the wake of Mr. Wright’s passing on Sunday, Mr. Walz and other officials in Minnesota known for policing reforms, including making sure officers cannot mistake their guns for their Taser.

“Why can’t we have Tasers that look and feel differently ? ” Mayor Melvin Carter of St. Paul said. “ you could never mistake for deploying a firearm, so that we can ensure that that error, which has occurred before, can never happen again. ”

Ed Obayashi, a California-based expert on the use of force by law enforcement and a deputy sheriff, said that with proper training, it needs to be difficult for officers to confuse a gun with a Taser, “but sadly it does occur — this isn’t the first time and it won’t be the last. ”

In most cases, said Deputy Obayashi, who is also a lawyer, the confusion happens when officers carry both firearms on the same side of their body, or holster their stun guns on the other side of their body with the grip facing backward so that they can use their dominant hand to “cross-draw. ”

Instances of police officers inadvertently shooting a handgun when they supposed to draw their Tasers, while not common, are not entirely unusual, either. In 2015, a former Oklahoma reserve deputy murdered an unarmed man when he accidentally grabbed his handgun. In 2018, a rookie Kansas police officer mistakenly shot a guy who had been fighting with a fellow officer. And in 2019, a police officer in Pennsylvania shouted “Taser! ” before shooting an unarmed man in the torso.

Within hours of Mr. Wright’s passing , people clashed with the police out of the Brooklyn Center police station, where officers fired tear gas and rubber bullets at protesters, some of whom threw bags of garbage and stones.

Hundreds of additional National Guard troops were flooding the metro area, adding to troops that have been standing by during Mr. Chauvin’s trial.

Residents said they were struggling to absorb the news of another death in the hands of a police officer — while the Chauvin trial was underway in Minneapolis.

Im very saddened, said Laura Vizenor, 56. “I simply don’t understand it and I don’t know how you yell ‘Taser’ and then fire your gun. It doesn’t make sense. ”

Nicholas Bogel-Burroughs reported from Brooklyn Center, Julie Bosman from Chicago, and Shawn Hubler from Sacramento. Shaila Dewan contributed reporting from Minneapolis, and Matt Furber from Brooklyn Center. Kitty Bennett contributed research.