The video of George Floyd gasping for breath was essentially Exhibit A as the former Minneapolis police officer who pressed his knee on the Black man’s neck went on trial Monday on charges of murder and manslaughter.

Prosecutor Jerry Blackwell showed the jurors the footage at the earliest opportunity, during opening statements, after telling them that the number to remember was 9 minutes, 29 seconds — the amount of time officer Derek 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 in the case that triggered worldwide protests, scattered violence and national soul-searching over racial justice.

“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 resisting arrest, and Chauvin arrived to assist other officers who were struggling to get Floyd into a squad car as the crowd around them grew larger and more hostile, Nelson said.

The defense attorney also disputed that Chauvin was to blame for Floyd’s death.

Floyd, 46, had none of the telltale signs of asphyxiation and had fentanyl and methamphetamine in his system, Nelson said. He said Floyd’s drug use combined with his heart disease and high blood pressure, as well as the adrenaline flowing through his body, to cause his death from a heart rhythm disturbance.

“There is no political or social cause in this courtroom,” Nelson said. “But the evidence is far greater than 9 minutes and 29 seconds.”

The medical examiner’s autopsy noted fentanyl and methamphetamine in Floyd’s system but listed his cause of death as “cardiopulmonary arrest, complicating law enforcement subdual, restraint, and neck compression.”

Chauvin, 45, is charged with unintentional second-degree murder, third-degree murder and manslaughter. The most serious charge, the second-degree murder count, carries up to 40 years in prison. The case is the first trial ever televised in Minnesota.

The first witness was Minneapolis police dispatcher Jena Scurry, who testified that she saw part of Floyd’s arrest unfolding via a city surveillance camera and was so disturbed that she called a duty sergeant. Scurry said she grew concerned because the officers hadn’t moved after several minutes.

“You can call me a snitch if you want to,” Scurry said in her call to the sergeant, which was played in court. She said she wouldn’t normally call the sergeant about the use of force because it was beyond the scope of her duties, but “my instincts were telling me that something is wrong.”

The video played during opening statements was posted to Facebook by a bystander who witnessed Floyd being arrested after he was accused of trying to pass a counterfeit $20 bill at a convenience store. The footage caused revulsion across the U.S. and beyond.

It prompted calls for the country to confront racism and police brutality. Confederate statues and other symbols were pulled down around the U.S., and activists demanded that police department budgets be cut or overhauled.

Jurors watched intently as the video played on multiple screens, with one drawing a sharp breath as Floyd said he couldn’t breathe. Chauvin sat calmly during opening statements and took notes, looking up at the video periodically.

“My stomach hurts. My neck hurts. Everything hurts,” Floyd says, and: “I can’t breathe, officer.” Onlookers repeatedly shout at the officers to get off Floyd. One woman, identifying herself as a city Fire Department employee, shouts at Chauvin to check Floyd’s pulse.

The timeline differs from the initial account submitted last May by prosecutors, who said Chauvin held his knee on Floyd’s neck for 8 minutes, 46 seconds. The time 8:46 soon became a rallying cry in the case. But it was revised during the investigation.

Fourteen people in the jury box are hearing the case — eight of them white, six of them Black or multiracial, according to the court. Two will be alternates, though the judge hasn’t said which ones will deliberate the case.

Blackwell said in his opening statement that the Fire Department first responder who wanted to administer aid was warned off by Chauvin, who pointed Mace at her.

“She wanted to check on his pulse, check on Mr. Floyd’s well-being,” Blackwell said. “She did her best to intervene. When she approached Mr. Chauvin …. Mr. Chauvin reached for his Mace and pointed it in her direction. She couldn’t help.”

About a dozen people chanted and carried signs outside the courthouse as Floyd family attorney Ben Crump, the Rev. Al Sharpton and members of the Floyd family went inside.

Crump said the trial would be a test of “whether America is going to live up to the Declaration of Independence,” and blasted the idea that it would be a tough test for jurors.

“We know that if George Floyd was a white American citizen, and he suffered this painful, tortuous death with a police officer’s knee on his neck, nobody, nobody, would be saying this is a hard case,” he said.

The downtown Minneapolis courthouse has been fortified with concrete barriers, fences and barbed and razor wire. City and state leaders are determined to prevent a repeat of the riots that followed Floyd’s death, with National Guard troops already mobilized.

Chauvin’s trial is being livestreamed, a first in Minnesota, by order of the judge and over the objections of the prosecution. Judge Peter Cahill ordered that cameras be allowed largely because of the pandemic and the required social distancing that meant there would be almost no room for spectators in the courtroom.

The Chauvin and Floyd families are allotted one seat each in the courtroom. Floyd’s brother Philonise represented the Floyd family on Monday. The seat for a Chauvin family member was empty, as it was all through more than two weeks of jury selection.