A photo of George Floyd is pictured on a fence alongside other victims of police brutality, in the Brooklyn borough of New York City on Sept 24, 2020. (ANGELA WEISS / AFP)

MINNEAPOLIS, Minnesota－The police officer whose actions led to the death of African American George Floyd betrayed his badge of service when he used excessive force during an arrest that triggered worldwide calls for racial justice, a court in Minneapolis was told on Monday.

"You will learn that on May 25, Mr Derek Chauvin betrayed this badge when he used excessive and unreasonable force upon the body of George Floyd," prosecutor Jerry Blackwell said on the opening day of the murder trial of Chauvin, who was sacked from the force days after video footage of him kneeling on Floyd's neck swamped the internet.

Blackwell is aiming for a rare conviction of a US police officer for killing a civilian.

The white officer Derek Chauvin "didn't let up" even after a handcuffed African American George Floyd said 27 times that he couldn't breathe and went limp, said prosecutor Jerry Blackwell

Ahead of opening statements in the trial, members of Floyd's family and their legal team knelt in front of the courthouse in Minnesota's capital for 8 minutes and 46 seconds, the duration that video taken from the scene showed Chauvin had knelt on Floyd's neck while the 46-year-old was handcuffed, pinned to the pavement, and pled that he could not breathe. The video, uploaded by a bystander, sparked a summer of protests last year.

"Today starts a landmark trial that will be a referendum on how far America has come on its quest for equality and justice for all," civil rights attorney Ben Crump said outside the court on Monday.

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"This murder case is not hard, just look at the torture video of George Floyd."

Chauvin, who is white, faces charges of second-degree murder, third-degree murder and second-degree manslaughter.

Video footage shown

Blackwell showed the jurors the footage at the earliest opportunity, during the opening statements, after telling them that the number to remember was 9 minutes, 29 seconds－the amount of time Chauvin had Floyd pinned to the pavement last May.

The white officer "didn't let up" even after a handcuffed Floyd said 27 times that he couldn't breathe and went limp, Blackwell said.

"He put his knees upon his neck and his back, grinding and crushing him, until the very breath－no, ladies and gentlemen－until the very life was squeezed out of him," the prosecutor said.

Chauvin attorney Eric Nelson countered by arguing: "Derek Chauvin did exactly what he had been trained to do over his 19-year career."

Floyd was fighting efforts to put him in a squad car as a crowd of onlookers around Chauvin and his fellow officers grew and became increasingly hostile, Nelson said.

The defense attorney also disputed that Chauvin, 45, was to blame for Floyd's death.

Floyd had none of the telltale signs of asphyxiation and he had fentanyl and methamphetamine in his system, Nelson said. He said Floyd's drug use, combined with his heart disease, high blood pressure and the adrenaline flowing through his body, caused a heart rhythm disturbance that killed him.

Bystander Donald Williams, who said he was trained in mixed martial arts, testified that Chauvin appeared to increase the pressure on Floyd's neck several times with a shimmying motion. He said he yelled to the officer that he was cutting off Floyd's blood supply.

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Williams said he saw Floyd "slowly fade away… like a fish in a bag".

Agencies via Xinhua contributed to this story.