In scenes both peaceful and violent across the country, thousands of protesters on Friday chanted "no justice, no peace" and "say his name. George Floyd." They hoisted signs reading: "He said I can't breathe. Justice for George."
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The demonstrations came as Derek Chauvin, the officer involved in Floyd's death, was arrested and charged with one count each of third-degree murder and second-degree manslaughter.
Graphic video footage taken on an onlooker's cellphone and widely circulated on the internet shows Floyd - with Chauvin's knee pressed into his neck - gasping for air and repeatedly groaning, "Please, I can't breathe," while a crowd of bystanders shouted at police to let him up.
The video reignited an outpouring of rage that civil rights activists said has long simmered in Minneapolis, the largest city in the state of Minnesota, and other towns and cities across the country over persistent racial bias in the US criminal justice system and the deaths of Black people in police custody.
Peaceful demonstrators observe a moment of silence outside the US Bank Stadium during the fourth day of protests after the killing of George Floyd in Minneapolis, Minnesota, US on May 29, 2020 [Nicholas Pfosi/Reuters]
The charges brought by Hennepin County prosecutors came after a third night of protests in which protesters set fire to a police station, and the National Guard was deployed to help restore order in Minneapolis.
Authorities had hoped Chauvin's arrest would allay public anger and avert continued unrest. But defying an 8pm curfew imposed by Mayor Jacob Frey, thousands took to the streets for a fourth night. A heavy contingent of National Guard, state troopers and police moved in, some on foot and some in vehicles.
"We saw a confrontation between a number of demonstrators and state police ... [that] ended with tear gas," Al Jazeera's John Hendren, reporting from Minneapolis, said.
Protester Naeema Jakes told AFP news agency she needed to be on the streets so she could verbally confront officers.
"I need you to look in my eyes and feel me," Jakes said. "This is pain, this is hurt."
Some cars were set on fire in scattered neighbourhoods, while a pair of restaurants and a Wells Fargo branch were also set ablaze.
A person walks amid two fires during a demonstration against the death in Minneapolis police custody of African American man George Floyd, in Minneapolis, Minnesota, US, May 30, 2020 [Lucas Jackson/ Reuters]
A group of protesters rally around the Fifth Police Precinct on May 29, 2020 in Minneapolis, Minnesota [Stephen Maturen/Getty Images via AFP]
Among the cities with larger protests on Friday were Atlanta, Denver, Detroit, Houston, Los Angeles and Louisville.
After hours of peaceful protest in central Atlanta, some demonstrators turned violent, smashing police cars, setting one on fire, spray-painting the logo sign at CNN's headquarters and breaking into a restaurant. The crowd pelted officers with bottles, chanting "quit your jobs".
Mayor Keisha Lance Bottoms pleaded with the crowd to go home.
"This is not a protest," she said. "You are disgracing our city. You are disgracing the life of George Floyd and every other person who has been killed in this country. We are better than this."
But the violence continued, prompting Georgia's Governor Brian Kemp to declare a state of emergency to "protect people & property in Atlanta".
Kemp said 500 members of the state National Guard would be deployed to quell the unrest.
Demonstrators paint on the CNN logo during a protest in Atlanta [Mike Stewart/ AP]
Protesters also gathered outside the White House, with President Donald Trump inside, and some tried to push through barriers set up by the US Secret Service along Pennsylvania Avenue.
In New York City, an initially peaceful demonstration spiralled into chaos as night fell. Protesters skirmished with officers, destroying police vehicles and setting fires.
In Brooklyn, activists who had marched from Manhattan chanted slogans against police brutality and pelted officers lined up outside the Barclays Center with water bottles. Police sprayed an eye-irritating chemical into the largely diverse crowd multiple times, then cleared the plaza.
Numerous people were arrested and police brought in buses to carry them off.
"We have a long night ahead of us in Brooklyn," Mayor Bill de Blasio tweeted. "Our sole focus is deescalating this situation and getting people home safe. There will be a full review of what happened tonight. We don't ever want to see another night like this."
People take part in a protest over Floyd's death in the Brooklyn borough of New York City, US, May 29, 2020 [Brendan McDermid/Reuters]
In Houston, where Floyd grew up, several thousand people rallied in front of City Hall. Among them was 19-year-old Jimmy Ohaz, who came from the nearby city of Richmond, Texas.
"My question is how many more, how many more? I just want to live in a future where we all live in harmony and we're not oppressed," he told The Associated Press news agency.
In Detroit, a 19-year-old man was killed after someone in a vehicle fired shots into a crowd of people protesting Floyd's death. Police said an officer was not involved in the shooting and the suspect had pulled up in a Dodge Durango and opened fire at the protesters.
Tensions also rose in several cities on the US's west coast as night fell and protesters blocked highways in Los Angeles and Oakland. Demonstrators in Los Angeles scuffled at times with police, with a few protesters arrested and one officer receiving medical treatment, police said.
The unrest was the worst the US has seen in years. The AP news agency, citing three anonymous sources said the Pentagon ordered the army to put military police units on alert to head to Minneapolis on short notice at Trump's request.
A protester holds his hands up as police officers enter Lafayette Park as the officers keep demonstrators away from the White House during a protest in Washington, DC, US, on May 30, 2020 [Tom Brenner/ Reuters]
Trump said on Friday he had spoken to Floyd's family and "expressed my sorrow".
He called the video of the arrest "just a horrible thing to witness and to watch. It certainly looked like there was no excuse for it".
Earlier in the day, Hennepin County Attorney Mike Freeman said a key piece of evidence in the case against Chauvin was the video clip showing Floyd lying face down in the street, with the officer kneeling on the back of Floyd's neck - Chauvin had his knee on Floyd's neck for nearly nine minutes, according to an autopsy report.
"We have evidence, we have the citizen's camera's video, the horrible, horrific, terrible thing we have all seen over and over again," Freeman said.
He added the investigation into Chauvin, who faces up to 25 years in prison if convicted, was ongoing and he anticipated also charging the three other officers, identified by the city as Thomas Lane, Tou Thao and J Alexander Kueng.
All four were fired from the police department on Tuesday after the video surfaced of Monday's arrest.
The 46-year-old Floyd's relatives welcomed the news of Chauvin's arrest as a "step on the road to justice". But they said they hoped for tougher charges and action against the other officers involved in Floyd's detention and death.
"We want a first-degree murder charge. And we want to see the other officers arrested," they said in a statement.
"The pain that the Black community feels over this murder and what it reflects about the treatment of Black people in America is raw and is spilling out onto streets across America."