Prosecutors said former police officer Derek Chauvin, 45, used lethal force against a "defenseless" 46-year-old and handcuffed Floyd for nine minutes and 29 seconds.
Floyd died of oxygen deprivation after being held on the ground by Chauvin, prosecutor Jerry Blackwell told the first day of Chauvin's trial.
But Chauvin's lawyer said in his opening remarks to the jury that the former officer was executing his training and 19 years' experience. However, Eric Nelson acknowledged the arrest video was disturbing to watch.
Nelson said Floyd died of a heart arrhythmia complicated by methamphetamines and fentanyl he had ingested before his arrest. "The use of force is not attractive but it is a necessary component of policing," Nelson said.
Earlier special assistant attorney general Jerry Blackwell said Chauvin "didn't let up, he didn't get up," even after Floyd said 27 times he couldn't breathe.
"Derek Chauvin betrayed this badge," Blackwell told the jury.
Chauvin and three other officers were trying to arrest Floyd on suspicion of using a fake $20 note to buy cigarettes - a misdemeanor prosecutors said might have been handled with a summons to appear in court instead of an arrest.
Chauvin, the former Minneapolis police officer is charged with the murder of Floyd, third-degree murder and manslaughter for the killing of Floyd in May.
