MINNEAPOLIS — A former police officer who pressed his knee into George Floyd’s neck until well past Mr. Floyd’s final breath was found guilty of murder on Tuesday in a case that shook the nation’s conscience and drew millions into the streets for the largest racial justice protests in generations.
The verdict, which could send the former officer, Derek Chauvin, to prison for decades, represented a rare rebuke for police violence, following case after case of officers going without charges or convictions after killing Black men, women and children.
At the center of it all was an excruciating video, taken by a teenage girl, that showed Mr. Chauvin, who is white, kneeling on the neck of Mr. Floyd, who was Black, for nine minutes and 29 seconds as Mr. Floyd pleaded for his life and bystanders tried to intervene. Mr. Floyd repeated “I can’t breathe” more than 20 times during the encounter.
The video, played on a horrifying loop for the past year, triggered more than calls for changes in policing. It sparked Americans of all races, in small towns and large cities, to gather for mass protests chanting “Black Lives Matter,” and challenging the country to finally have a true reckoning over race. Their demands reverberated within the walls of institutions that had long resisted change, from corporate America to Congress.
This week, over the course of two days, a racially diverse jury of seven women and five men deliberated for just over 10 hours before pronouncing Mr. Chauvin guilty on all three charges: second-degree murder, third-degree murder and second-degree manslaughter.
President Biden praised the verdict in a nationwide address at the White House on Tuesday, but called it a “too rare” step to deliver “basic accountability” for Black Americans.
“It was a murder in full light of day, and it ripped the blinders off for the whole world to see,” Mr. Biden said. “For so many, it feels like it took all of that for the judicial system to deliver just basic accountability.”
Hours before the jury came back with a decision, Mr. Biden had taken the unusual step of weighing in, telling reporters that he was “praying” for the “right verdict.”
“This can be a giant step forward in the march toward justice in America,” he said.
After the verdict, Philonise Floyd, one of Mr. Floyd’s younger brothers, spoke at the Hilton hotel in downtown Minneapolis. “We are able to breathe again,” he said, holding back tears.
He drew a line from his brother back to Emmett Till, a Black child who was lynched in Mississippi in 1955. “We ought to always understand that we have to march,” he said. “We will have to do this for life. We have to protest because it seems like this is a never-ending cycle.”
People gathered at the intersection where Mr. Floyd died, now known as George Floyd Square, and the word “Guilty” rippled throughout the crowd there after the verdict was announced, prompting cheers and sobs. The crowd began to chant, “Black lives matter.”
Mr. Chauvin, who had been free on bail during the trial, was ordered into custody by the judge, Peter A. Cahill, and was taken out of the courtroom in handcuffs.
The verdict was hailed across the country by civil rights leaders and honking motorists. It gave a tense nation a moment to exhale, even as new police killings in a Minneapolis suburb, Chicago and, on Tuesday afternoon, Columbus, Ohio, sent Americans back into the streets, holding signs that asked, “How many more?”
The case was handled by the office of Attorney General Keith Ellison of Minnesota, the first Black man to hold statewide office. Prosecutors mounted perhaps the most ambitious and extensive case in any trial of an officer for an on-duty killing.
With a rotating cast of prominent lawyers, some of whom volunteered their services, the state presented 11 days of testimony from onlookers, paramedics, fellow police officers and a phalanx of medical experts armed with formulas, charts and timelines.
Among the state’s star witnesses was the chief of the Minneapolis police, Medaria Arradondo, who said Mr. Chauvin had “absolutely” violated training, ethics and several department policies when he kept Mr. Floyd pinned facedown on the street long after he took his final breath. It is exceedingly rare for a chief to testify against an officer from his own department.
The presumptive sentence for the most serious charge, second-degree murder, is 12.5 years, according to Minnesota’s sentencing guidelines. But the prosecution has asked for a lengthier sentence, arguing that there were children present at the scene, that Mr. Chauvin treated Mr. Floyd with “particular cruelty,” and that he “abused his position of authority.”
The judge will sentence Mr. Chauvin, 45, in eight weeks.
George Floyd, 46, was a grandfather, a rapper known as Big Floyd and a security guard who had lost his job during the coronavirus pandemic. On the day he died — May 25, 2020 — the Minneapolis police responded to a call saying that he had used a counterfeit $20 bill to buy cigarettes at a corner store, Cup Foods.
Mr. Floyd initially cooperated with officers but he balked at getting into the back of a squad car, saying he was claustrophobic. A struggle ensued that resulted in three officers holding him prone on the street and one standing guard.
Mr. Chauvin was a field training officer and the senior officer at the scene, with 19 years on the force. As he knelt on Mr. Floyd, sometimes with both knees, he dismissed concerns or suggestions raised by the other officers that Mr. Floyd was passing out, had no detectable pulse and should be moved onto his side, a less dangerous position.
When Mr. Floyd said, “You’re going to kill me, man,” Mr. Chauvin replied: “Then stop talking, stop yelling. It takes a heck of a lot of oxygen to talk.”
Mr. Chauvin continued to kneel on him for about three minutes after Mr. Floyd drew his final breath, according to expert testimony.
Prosecutors began their case with a series of eyewitnesses to Mr. Floyd’s death, who offered emotional testimony about the trauma and guilt they were left with.
While Mr. Chauvin’s lawyer, Eric J. Nelson, attempted to paint those bystanders — who had been out to buy a cellphone cord or a drink, or just to take a walk — as a dangerous and unruly mob, each offered an account of the desperation and helplessness he or she felt watching Mr. Floyd become unconscious beneath the officer’s knee.
“They saw that a human being they did not know was suffering,” Jerry W. Blackwell, one of the prosecutors, said in his closing argument, calling them a “bouquet of humanity.” He added, “And they wanted to try to intervene to stop the suffering.”
One of the witnesses that day, Charles McMillian, broke down on the witness stand as he recalled seeing Mr. Floyd cry out for “Mama.” Another witness, Darnella Frazier, who recorded the cellphone video that was viewed by millions, said she regretted that she had not done more to try to save Mr. Floyd.
“It’s been nights I stayed up apologizing and apologizing to George Floyd for not doing more and not physically interacting and not saving his life,” Ms. Frazier said.
The trial was held in a closely guarded government building surrounded by high temporary fencing. Jurors were kept anonymous to protect them from potential threats. Because of the pandemic, Judge Cahill allowed the proceedings to be livestreamed, an exception to Minnesota’s strict rules governing cameras in the courtroom. Jurors sat in chairs spaced six feet apart instead of close together in a traditional jury box, and only two spectators — one from Mr. Floyd’s family, one from Mr. Chauvin’s — were allowed to be present at a time.
The case continues to have broad effects on Minneapolis, where more than 1,000 buildings were damaged or destroyed by vandalism and looting in the unrest that followed Mr. Floyd’s death. The Third Precinct building, which was set on fire, is boarded up. The intersection where Mr. Floyd was killed remains closed to traffic. And the city has endured an agonizing debate over the future of its Police Department.
Community activists celebrated the verdict, albeit gingerly. It was “one trial and one moment in history,” Nekima Levy Armstrong, a civil rights lawyer, said on Minnesota Public Radio. “However, this moment didn’t happen because the system worked,” she added. “This moment happened because the people put in the work. We had to demand justice and accountability.”
Mr. Ellison, whose office prosecuted the case, called it an “inflection point” and called for a broader shift in how the police interact with the communities they serve.
“Although a verdict alone cannot end their pain, I hope it’s another step on the long path toward healing for them,” Mr. Ellison said of the Floyd family. “There is no replacing your beloved Perry, or Floyd, as his friends called him, but he is the one who sparked a worldwide movement, and that’s important.”
Before a jury had even been assembled, the prosecution, the defense and the judge sought to keep the trial’s symbolic heft out of the courtroom.
With strong public opinions and an inescapable torrent of media coverage, the judge allotted three weeks for jury selection, allowing each side to question potential jurors one on one to determine if they could set aside their feelings about the case.
More than 300 Hennepin County residents summoned for jury duty filled out 14-page questionnaires asking them what they knew about the case and what their opinions were on the Black Lives Matter movement, the protests unleashed by Mr. Floyd’s death and policing in general.
Mr. Chauvin’s lawyer, Mr. Nelson, suggested to potential jurors that perhaps “this case is not about race at all.” During opening arguments he said, “There is no political or social cause in this courtroom.”
The prosecution, for its part, said that policing itself was not on trial. “The defendant is on trial not for being a police officer — it’s not the state versus the police,” Steve Schleicher, a lawyer for the state, said in his closing argument. “He’s not on trial for who he was. He’s on trial for what he did.”
The 12-person jury included three Black men, one Black woman and two women who identified as multiracial.
The trial centered on two issues: whether what Mr. Chauvin had done was reasonable given the situation, and whether he had caused Mr. Floyd’s death. The defense argued that Mr. Floyd’s heart disease, high blood pressure and other health conditions, as well as his use of methamphetamine and fentanyl, contributed to his death.
Though it presented dozens of witnesses, the prosecution ultimately asked jurors to focus on the central piece of evidence: the video taken by Ms. Frazier, which was shown repeatedly in court. “Believe your eyes,” the jury was told.
“This case is exactly what you thought when you saw it first, when you saw that video,” Mr. Schleicher said in the closing argument. “It’s what you felt in your gut. It’s what you now know in your heart.”
Reporting was contributed by Andrés R. Martínez, Will Wright, Marie Fazio, Lucy Tompkins and Katie Rogers.