Ex-cop Derek Chauvin, who is already serving a long prison sentence for the killing of African American George Floyd, has been sentenced to more than 20 years in prison in a separate federal trial.

The verdict came Thursday in Saint Paul after the defendant pleaded guilty to violating Floyd's civil rights in the trial.

The agonizing death of George Floyd, who was struggling for air, triggered global protests against police violence and racism in 2020.

On May 25, 2020 in Minneapolis, the white US policeman had kneed Floyd, who had been arrested and handcuffed on allegations of counterfeit money, for around nine and a half minutes, although the 46-year-old black man repeatedly complained that he could not breathe.

Floyd's agonizing death, captured on cellphone video, sparked international outrage and sparked nationwide protests against racism and police violence.

Floyd's complaint "I can't breathe" - "I can't breathe" or "I can't breathe" - went around the world and became a motto of the anti-racism movement Black Lives Matter.

In June 2021, Chauvin was sentenced to 22 years and six months in Minnesota for second-degree murder.

In parallel with the state judiciary, the federal judiciary had brought charges against Chauvin, as is possible in the United States.

She accused the ex-cop of violating Floyd's constitutional right not to suffer "disproportionate force at the hands of a police officer."

Chauvin pleaded guilty to this – now the verdict was also in this case.

The two prison sentences can be served at the same time under US law.