CHARLOTTE, N.C. — A second night of protests set off by the police killing of a black man spiraled into chaos and violence after nightfall here Wednesday when a demonstration was interrupted by gunfire that gravely wounded a man in the crowd. Law enforcement authorities fired tear gas in a desperate bid to restore order.
The Charlotte City Council said in a statement that the unidentified man was on life support after what city officials said was a “civilian on civilian” confrontation. The authorities provided no further details.
City officials had said earlier that the man had been killed in the unrest. One police officer was reported slightly injured during the chaos.
The shooting heightened the tension among the demonstrators and the police alike. City officials were quick to say the police had not fired any live rounds, but riot police personnel did fire several rounds of tear gas.
The scene of the shooting and the largest demonstration of the evening happened along a crowded street in Charlotte’s city center, where the sound of gunfire mixed with the noise of people banging objects into vehicles.
The gunshot victim lay motionless on the ground, his eyes open, as people surrounded him and blood pooled between their feet. He was taken into the nearby Omni Hotel, and a series of physical confrontations played out afterward as the police kept people from entering.
Some demonstrators immediately accused the police of opening fire, a charge the authorities quickly denied. The city described the episode as a “civilian on civilian” confrontation.
There was sporadic looting. Twitter messages showed that the team store of the Charlotte Hornets of the N.B.A. had been broken into and gutted of merchandise. “We are working very hard to bring peace and calm back to our city,” Mayor Jennifer Roberts said on CNN.
Around 10 p.m., the police ordered all civilians, including members of the media, to leave parts of Uptown and threatened arrests of those who did not comply. When the crowd did not respond immediately, within minutes the authorities fired more tear gas.
The mayhem, in the heart of Charlotte’s dazzling Uptown district, was the second night of extraordinary tension in North Carolina’s largest city, where a police officer killed a black man on Tuesday afternoon.
On Wednesday night, police officers, many of them dressed in riot gear and standing in formation, made numerous arrests. A helicopter flew over Uptown, and on the streets below, protesters were heard chanting, “Hands up! Don’t shoot!”
Around 10 p.m., the police ordered people to leave parts of Uptown and threatened arrests. Within minutes, the authorities fired more tear gas.
The unrest in Charlotte came after two other police-involved deadly shootings within the last week.
First came the shooting of a teenager in Columbus, Ohio, who had been brandishing a BB gun. Two days later, on Friday, was the shooting death in Tulsa, Okla., of a man who had his hands above his head before an officer opened fire.
And then it was Charlotte, where Keith L. Scott, 43, black like the other two, was shot by a police officer in a parking space marked “Visitor” outside an unremarkable apartment complex on Tuesday. On Wednesday that parking space was both the site of a fatal shooting and a shrine, and Charlotte was a city on edge, the latest to play a role in what feels like a recurring, seemingly inescapable tape loop of American tragedy.
“To see this happen multiple times — just time after time — it’s depressing, man,” said Tom Jackson, 25, who works with mentally disabled people. He didn’t know Mr. Scott but was drawn here nonetheless, one of many strangers and friends who came to pay their respects and make sense of their sorrow.
In addition to the fatal attacks on police officers in Baton Rouge and Dallas, it was another grim snapshot of America’s continuing crisis in black and blue, this moment amplified by presidential politics. And as usual, there was very little consensus on what went wrong and how to fix it.
At a news conference on Wednesday, Kerr Putney, chief of the Charlotte-Mecklenburg Police Department, said officers had found the gun that the police said Mr. Scott had brandished before an officer fatally shot him and were examining police video of the encounter that unfolded as Mr. Scott stepped out of a car.
Family members of Mr. Scott have said that he was unarmed and was holding only a book. Chief Putney said Wednesday morning, “We did not find a book.”
The response of B.J. Murphy, an African-American activist here, could not have been more different: “Everybody in Charlotte should be on notice that black people, today, we’re tired of this,” he said, adding an epithet. “We’re tired of being killed and nobody saying nothing. We’re tired of our political leaders going along to get along; they’re so weak, they don’t have no sympathy for our grief. And we want justice.”
All three shootings are under investigation, and are rife with questions and complications. The police in Columbus said that the BB gun wielded by 13-year-old Tyre King was built to look nearly identical to a Smith & Wesson Military & Police semiautomatic pistol. Mayor Andrew J. Ginther blamed the shooting, in part, on Americans’ “easy access to guns, whether they are firearms or replicas.”
In Tulsa, the police said investigators found the drug PCP in Mr. Crutcher’s S.U.V. The drug is known to induce erratic behavior in some users. But Mr. Crump, who is representing Mr. Crutcher’s family, said the discovery of the drug, if true, would not justify the deadly shooting.
In an interview on Wednesday, Mr. Crutcher’s father, the Rev. Joey Crutcher, said his son had marched in protest of earlier police killings of blacks and had thought thoroughly about how to protect himself during interactions with police officers.
They had planned to go to a church event aimed at teaching people how behave around the police and avoid becoming another hashtag shared on social media by Black Lives Matter protesters.
“I never thought this would happen to my family,” Mr. Crutcher said, adding that he had counseled his son all his life about how to behave around the police.
“I said, ‘Whenever you’re stopped by a police and you’re in that situation, raise your hands up, always let them see your hands, let them see that you are not going for a gun.’ And that is what Terence was doing. I said, ‘Always put your hands on your car.’ I made that specific, ‘your car.’ And that’s what Terence was walking to do on his car so that they could see his hands.”
John Barnett, a civil rights activist in Charlotte, said during a raucous news conference near the site of the shooting that Mr. Scott had been waiting for his son to arrive home from school.
“The truth of the matter is, he didn’t point that gun,” Mr. Barnett said. “Did he intend to really sit in a vehicle, waiting on his son to get home from school and then plot to shoot a cop if they pulled up on him?”
Adding to an atmosphere loaded with suspicion and mistrust, residents of the apartment complex gave varying accounts of Mr. Scott’s death.
Some differed from the police on which officer fired the shots, and others said that no one had tried to administer CPR for Mr. Scott as officials had said.
“Since black lives do not matter for this city, then our black dollars should not matter,” said Mr. Murphy, the activist. “We’re watching a modern-day lynching on social media, on television and it is affecting the psyche of black people.”
Attorney General Loretta E. Lynch said Wednesday that the Justice Department “is aware of, and we are assessing, the incident that led to the death of Keith Lamont Scott in Charlotte.”
Responding to another police shooting, the state’s attorney in Baltimore County, Md., Scott D. Shellenberger, announced Wednesday that no charges would be filed against any of the officers involved in the Aug. 1 shooting death of Korryn Gaines or the shooting of her 5-year-old son.
In Charlotte, Rakeyia Scott, Mr. Scott’s wife, said on Wednesday the family was “devastated” by the shooting. She described her husband as “a loving husband, father, brother and friend.”
Ms. Scott said that after hearing the police chief’s remarks, the family had “more questions than answers about Keith’s death.” She also asked protesters to remain peaceful.
At a campaign rally in Orlando, Fla., Hillary Clinton spoke about the shootings here and in Tulsa.
“There is still much we don’t know about what happened in both incidents, but we do know that we have two more names to add to a list of African-Americans killed by police officers in these encounters,’’ she said.
“It’s unbearable, and it needs to become intolerable. We also saw the targeting of police officers in Philadelphia last week. And last night in Charlotte, 12 officers were injured in demonstrations following Keith Scott’s death. Every day police officers are serving with courage, honor and skill.”
Her Republican rival, Donald J. Trump, reacted on Twitter. “Hopefully the violence & unrest in Charlotte will come to an immediate end,” he wrote. “To those injured, get well soon. We need unity & leadership.”
Unity, thus far, has been in short supply. On Friday, Mr. Trump earned the endorsement of the Fraternal Order of Police. But polls show that his support among African-Americans is negligible, even though he has singled them out in promising to solve the ills of poverty and violence that he has characterized as plaguing black neighborhoods.
On Wednesday, Mr. Jackson, the man who came here to mourn, was not thinking about the candidates of today, but the candidates of the future, and potential squandered by the lives cut short.
The police, he said, “are out here killing people, and they don’t even know their backgrounds,” he said. “They could be killing the next president.”
Correction: September 21, 2016
An earlier version of this article gave an incorrect time for the shooting. It occurred just before 4 p.m., not after 4.