A jury has found former Minneapolis policeman Derek Chauvin guilty of second-degree murder, third-degree murder and manslaughter in the deadly arrest of George Floyd.
Chauvin, 45, was filmed kneeling on Floyd's neck for more than nine minutes during his arrest last May.
After nine hours deliberation, the jury found Chauvin criminally liable in Floyd's death. They considered three weeks of testimony from 45 witnesses, including bystanders, police officials and medical experts.
US president Joe Biden said such a verdict was too rare, but could be a "giant step forward in the march toward justice in America".
Earlier, Biden had said he was praying for the "right verdict" in the trial. Biden, who spoke to Floyd's family on Monday, said he believed the case was "overwhelming".
Chauvin, who is white, pleaded not guilty to second-degree unintentional murder, third-degree "depraved mind" murder and second-degree manslaughter.
All three charges required that jurors found Chauvin's acts were a "substantial causal factor" in Floyd's death, but none require that they found he intended to kill Floyd.
In an arrest captured on video, Chauvin pushed his knee into the neck of Floyd, a 46-year-old handcuffed Black man, for more than nine minutes outside the grocery store where Floyd had been accused of buying cigarettes with a fake $20 bill.
Floyd's relatives, many of them travelling from Texas, have taken turns sitting in a single chair reserved for them in the courtroom, where seating was limited due to Covid-19 restrictions.
The judge let the proceedings be broadcast live to the public, a Minnesota first.
Floyd's death prompted protests against racism and police brutality in many cities in the United States and around the world last year. The courthouse in Minneapolis was surrounded by high barricades and guarded by National Guard troops. Many downtown businesses boarded up their windows as they braced for the verdict.
Under Minnesota sentencing guidelines, Chauvin faces 12-and-a-half years in prison for his murder conviction as a first-time criminal offender. Prosecutors could, however, seek a longer sentence up to the maximum of 40 years if Hennepin County District Judge Peter Cahill, who presided over the trial, determines that there were "aggravating factors."
In Minnesota, convicted criminals generally leave prison on supervised release after completing two thirds of their sentence. Chauvin had no previous criminal convictions.
A cardiologist, a pulmonologist, a toxicologist and a forensic pathologist were medical experts called by prosecutors to testify that videos and autopsy results confirmed that Chauvin killed Floyd by compressing his body into the street in a way that starved him of oxygen.
The defense argued that Chauvin behaved as any "reasonable police officer" would have under these circumstances, and sought to raise doubts about the cause of Floyd's death, saying heart disease or even the exhaust fumes from the nearby police car may have been factors.
The Minneapolis Police Department fired Chauvin and three other officers the day after Floyd's arrest. The three others are due to face trial later this year on aiding-and-abetting charges in Floyd's death.
The jury is comprised of four white women, two white men, three Black men, one Black woman and two multiracial women, according to court records. The court has promised to shield their identities until some time after they give their verdict. Hennepin County District Judge Peter Cahill presided over the trial.
The judge ordered the jurors to be sequestered after they began deliberations.