Chauvin's lead lawyer, Eric Nelson, countered that Chauvin behaved as any "reasonable police officer" would, arguing he followed his training from 19 years on the force.
Over and over again, prosecutor Steve Schleicher repeated a phrase: "Nine minutes and 29 seconds" - the length of time Chauvin was captured on video on May 25, 2020, with his knee pressed into the dying Floyd's neck.
Although the jury's verdict will be seen as a reckoning in the way the United States polices black people, Schleicher emphasised that the jury was weighing the guilt of only one man, not a system.
"This wasn't policing; this was murder," Schleicher told jurors on Monday. He cited the motto of the Minneapolis Police Department, which fired Chauvin and three other officers after Floyd's arrest: "To protect with courage and to serve with compassion."
Chauvin, who is white, pushed his knee into the neck of Floyd, a 46-year-old handcuffed black man, for more than nine minutes outside the grocery store where he had been suspected of buying cigarettes with a fake $US20 bill.
"He was trapped with the unyielding pavement beneath him, as unyielding as the men who held him down," Schleicher said, before playing some of the extensive video of Floyd's death, which he said showed Chauvin mocking Floyd's struggle to breathe.
Hennepin County District Judge Peter Cahill gave the jury final instructions before they left the courtroom to begin their deliberations. Jurors will be sequestered in a hotel outside of deliberation hours.
Chauvin has pleaded not guilty to second-degree unintentional murder, third-degree "depraved mind" murder and second-degree manslaughter.
Nelson, his lawyer, said prosecutors were wrong to dismiss his theory that carbon monoxide poisoning from the nearby police car's exhaust and Floyd's use of fentanyl, an opioid painkiller, may have contributed to Floyd's death.
He repeated a single phrase scores of times, saying Chauvin behaved as a "reasonable police officer" would in dealing with a man as "large" as Floyd, who was struggling against being put in a police car when Chauvin arrived, responding to a call for back-up.
In a final rebuttal before deliberations began, Jerry Blackwell, another prosecutor, scoffed at the carbon monoxide theory.
"What 'reasonable police officer,' when apprehending someone on the ground, subdues them and puts their face in front of a tailpipe of a car, and then thinks that's a defence?" he asked.
The extensive video footage of Floyd's death from multiple angles is the heart of the prosecution's case.
"You can believe your eyes," Blackwell said. "It was what you saw. It was homicide."
He said it showed Chauvin using unreasonable, and therefore illegal, force in compressing Floyd's torso against the road, starving him of oxygen.
He said it was something that was obvious even to the youngest bystander, who testified in the first week. "Even a nine-year-old little girl knows it: get off of him," Blackwell said.
But Nelson used the same videos to try to prove the opposite point: the fact Chauvin continued kneeling on Floyd even as he knew he was being filmed was evidence he believed he was responding in a reasonable way, Nelson said.
TV networks carried live broadcasts of testimony after the first of more than 40 witnesses took the stand three weeks ago, though the coverage was sometimes interrupted by fresh episodes of police violence caught on camera.
The closest instance occurred a few kilometres from the courthouse in downtown Minneapolis when a white police officer fatally shot a black motorist, Daunte Wright, on April 11 in a traffic stop.
As angry protests swelled, Minneapolis and state officials have ramped up security precautions. The tower in which the courtroom sits is ringed by barbed wire and armed soldiers from the National Guard.