Former Minneapolis police Officer Derek Chauvin has been sentenced to 22 years and six months for the murder of George Floyd.

Floyd's slow death under Chauvin's knee set off a fierce and sometimes violent reckoning over racial injustice in America.

Chauvin, 45, is also awaiting trial on federal civil rights charges in Floyd's death, along with three other fired officers who have yet to have their state trials.

The concrete barricades, razor wire and National Guard patrols at the courthouse during Chauvin's three-week trial in the spring were gone today, reflecting an easing of tensions since the verdict in April. Still, there was recognition the sentencing was another major step forward for Minneapolis since Floyd died on May 25, 2020.

Chauvin broke his long courtroom silence today, offering condolences to Floyd's family and saying he hopes more information coming out will give them "some peace of mind".

Chauvin, who did not testify at his trial, removed his face mask and turned toward the Floyd family, speaking only briefly because of what he called "some additional legal matters at hand" — an apparent reference to the federal civil rights trial he still faces.

Former Minneapolis police Officer Derek Chauvin addresses the court before his sentencing. It is the first time Chauvin has spoken. Photo / via AP

"But very briefly, though, I do want to give my condolences to the Floyd family. There's going to be some other information in the future that would be of interest. And I hope things will give you some peace of mind," he said, without elaborating.

Chauvin was convicted in April of second-degree unintentional murder, third-degree murder and second-degree manslaughter for pressing his knee against Floyd's neck for up to 9 1/2 minutes as the 46-year-old Black man gasped that he couldn't breathe and went limp.

Bystander video of Floyd's arrest on suspicion of passing a counterfeit $20 bill at a corner store prompted protests around the world and led to scattered violence in Minneapolis and beyond.

The site where George Floyd was killed by then Minneapolis Police officer Derek Chauvin. Photo / AP

Minnesota sentencing guideline s called for 12 1/2 years, but Judge Peter Cahill agreed with prosecutors before the proceedings there were aggravating circumstances that could justify a heavier punishment — among them, that Chauvin treated Floyd with particular cruelty, abused his position of authority as a police officer and did it in front of children.

Prosecutors asked for 30 years, saying Chauvin's actions were egregious and "shocked the nation's conscience."

The defence requested probation, saying Chauvin was the product of a "broken" system and "believed he was doing his job".

With good behaviour, Chauvin could get out on parole after serving about two-thirds of his sentence.

Before the sentencing, the judge denied Chauvin's request for a new trial. Defence attorney Eric Nelson had argued the intense publicity tainted the jury pool and the trial should have been moved away from Minneapolis.

The judge also rejected a defence request for a hearing into possible juror misconduct. Nelson had accused a juror of not being candid during jury selection because he didn't mention his participation in a march last summer to honor the Reverend Martin Luther King Jr. Prosecutors countered the juror had been open about his views.

In this May 25, 2020 file image from police body camera video shows George Floyd responding to police after they approached his car outside Cup Foods in Minneapolis. Photo / via AP

Ben Crump, an attorney for the family, said relatives were "anxious and tense" before the proceedings.

"To us, George Floyd is a cause. He's a case. He's a hashtag. To them - that's their flesh and blood. You know, that that's their brother," Crump said.

Philip Stinson, a criminal justice professor at Bowling Green State University, said 11 non-federal law officers, including Chauvin, had been convicted of murder for on-duty deaths since 2005. The penalties for the nine who were sentenced before Chauvin ranged from from six years, nine months to life behind bars, with the median being 15 years.

With Chauvin's sentencing, the Floyd family and Black America faced something of a rarity: in the small number of instances in which officers accused of brutality or other misconduct against Black people have gone to trial, the list of acquittals and mistrials is longer than the list of sentencings after conviction.

Preschool children visit the site where George Floyd was murdered by then Minneapolis Police officer Derek Chauvin. Photo / AP

In recent years, the acquittals have included officers tried in the deaths of Philando Castile in suburban Minneapolis and Terence Crutcher in Tulsa, Oklahoma. Two mistrials were declared over the death of Samuel Dubose in Cincinnati.

"That's why the world has watched this trial, because it is a rare occurrence," said Arizona-based civil rights attorney Benjamin Taylor, who has represented victims of police brutality. "Everybody knows that this doesn't happen every day."

Several people interviewed in Minneapolis before Chauvin's sentencing said they wanted to see a tough sentence.

Thirty years "doesn't seem like long enough to me," said Andrew Harer, a retail worker who is white. "I would be fine if he was in jail for the rest of his life."

Joseph Allen, 31, who is Black, said he would like to see Chauvin get a life sentence, adding he hopes other police officers learn "not to do what Derek Chauvin did".

As for whether she would like to hear Chauvin speak, Levy Armstrong said: "For me as a Black woman living in this community, there's really nothing that he could say that would alleviate the pain and trauma that he caused ... I think that if he spoke it would be disingenuous and could cause more trauma."

Chauvin has been held since his conviction at the state's maximum-security prison in Oak Park Heights, where he has been kept in a cell by himself for his own protection, his meals brought to him.

The three other officers are scheduled for trial in March on state charges of aiding and abetting both murder and manslaughter.

- AP