A federal grand jury has charged Derek Chauvin and three other former Minneapolis police officers with civil rights crimes in connection with the death of George Floyd, the Justice Department announced Friday.

Chauvin, 45, was convicted of murder and manslaughter last month for his role in the May 25, 2020 death of Floyd, a 46-year-old Black man.

Three other officers -- Tou Thao, 35, J. Alexander Kueng, 27, and Thomas Lane, 38 -- who were involved in Floyd's fatal arrest are also facing state charges and are to go on trial later this year.

The federal charges unsealed on Friday are separate from those brought against the former officers by the state of Minnesota.

The federal indictment accuses Chauvin of depriving Floyd of his constitutional right "to be free from the use of unreasonable force by a police officer."

A video taken by a bystander showed Chauvin, who is white, kneeling on Floyd's neck for more than nine minutes as he was handcuffed facedown on the street struggling to breathe.

The video went viral and sparked protests against racial injustice and police brutality across the United States and around the world.

Thao and Kueng were charged with failing to intervene to stop Chauvin's use of unreasonable force.

All four officers were charged with failing to provide assistance to someone in "clear need" of medical care.

A separate federal indictment charged Chauvin with using unreasonable force against a 14-year-old Minneapolis resident in a September 4, 2017 incident.

"Chauvin, without legal justification, held the teenager by the throat and struck the teenager multiple times in the head with a flashlight," the indictment alleges, resulting in "bodily injury to the teenager."

"Chauvin held his knee on the neck and the upper back of the teenager even after the teenager was lying prone, handcuffed, and unresisting, also resulting in bodily injury," it said.

Chauvin is to be sentenced on June 25 and faces up to 40 years in prison on the most serious charge -- second-degree murder.