A federal grand jury has indicted the four former Minneapolis police officers involved in George Floyd’s arrest and death, accusing them of willfully violating the black man’s constitutional rights as he was restrained face-down on the pavement and gasping for air.

A three-count indictment unsealed yesterday names Derek Chauvin, Thomas Lane, J Kueng and Tou Thao. Specifically, Chauvin is charged with violating Mr Floyd’s right to be free from unreasonable seizure and unreasonable force by a police officer. Mr Thao and Mr Kueng are also charged with violating Mr Floyd’s right to be free from unreasonable seizure, alleging they did not intervene to stop Chauvin as he knelt on Mr Floyd’s neck. All four officers are charged for their failure to provide Mr Floyd with medical care.

Mr Floyd’s May 25 arrest and death last year, which a bystander captured on cellphone video, sparked nationwide complaints about the police treatment of black people and protests calling for an end to police brutality and racial inequities.

Chauvin was also charged in a second indictment, stemming from the use of force and neck restraint of a 14-year-old boy in 2017.

Mr Lane, Mr Thao and Mr Kueng made their initial court appearances yesterday via videoconference in US District Court in Minneapolis. Chauvin was not part of the court appearance.

Chauvin was convicted last month on state charges of murder and manslaughter in Mr Floyd’s death and is in Minnesota’s only maximum-security prison as he awaits sentencing.

The other three former officers face a state trial in August, and they are free on bond. They were allowed to remain free after yesterday’s federal appearance.

Mr Floyd (46) died after Chauvin pinned him to the ground with a knee on his neck, even as Mr Floyd, who was handcuffed, repeatedly said he couldn’t breathe. Mr Kueng and Mr Lane also helped restrain Mr Floyd – state prosecutors have said Mr Kueng knelt on Mr Floyd’s back and Mr Lane held down Mr Floyd’s legs. State prosecutors say Mr Thao held back bystanders and kept them from intervening during the nine-and-a-half-minute restraint.

Chauvin’s attorney, Eric Nelson, argued during his murder trial that Chauvin acted reasonably in the situation and that Mr Floyd died because of underlying health issues and drug use. He has filed a request for a new trial, citing many issues including the judge’s refusal to move the trial due to publicity.

Ben Crump and the team of attorneys for Mr Floyd’s family said the civil rights charges reinforce “the strength and wisdom” of the Constitution. “We are encouraged by these charges and eager to see continued justice in this historic case that will impact black citizens and all Americans for generations to come,” the attorneys said in a statement.

The Reverand Al Sharpton said the federal charges against the officers show the Justice Department “does not excuse it nor allow police to act as though as what they do is acceptable behaviour in the line of duty”.

“What we couldn’t get them to do in the case of Eric Garner, Michael Brown in Ferguson, and countless others, we are finally seeing them do today,” Sharpton said.

Minnesota Attorney General Keith Ellison, whose office is prosecuting the state charges, said the federal government is responsible for protecting the civil rights of every American and “federal prosecution for the violation of George Floyd’s civil rights is entirely appropriate”, particularly now that Chauvin is convicted of murder.

To bring federal charges in deaths involving police, prosecutors must believe an officer acted under the “colour of law,” or government authority, and willfully deprived someone of their constitutional rights, including the right to be free from unreasonable seizures or the use of unreasonable force.