Derek Chauvin has been given a 21-year jail sentence for violating George Floyd's civil rights.
Chauvin will serve the federal sentence at the same time he serves his 22-and-a-half year sentence on state charges of murder and manslaughter.
The former police officer pinned George Floyd to the pavement outside a Minneapolis corner shop for more than nine minutes as he lay dying on May 25, 2020.
Chauvin was told by US District Judge Paul Magnuson what he did was "simply wrong" and "offensive".
Mr Magnuson said: "I really don't know why you did what you did.
"To put your knee on a person's neck until they expired is simply wrong."
Floyd's brother Philonise also asked for the maximum possible sentence.
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He said: "My family and I have been given a life sentence.
"We will never get George's life back."
Federal prosecutors had asked the judge to sentence Chauvin to 25 years.
Chauvin initially pleaded not guilty to the federal charges, but changed his plea in December.
Chauvin's lawyer Eric Nelson had asked for 20 years, arguing that he was remorseful.
However, he made no direct apology or expression of remorse to Floyd's family in court.
Instead, he told the family that he wishes Floyd's children "all the best in their life" and that they have "excellent guidance in becoming good adults".
For the first time Chauvin admitted he kept his knee on Floyd's neck, even when he said he couldn't breathe.
The murder sparked protests against racism and police brutality across the world.
Mr Magnuson has not set sentencing dates for the three other officers who were on the scene - Tou Thao, J. Alexander Keung and Thomas Lane – who were convicted in February of federal civil rights charges.