The trial of former Minneapolis police officer Derek Chauvin has begun, 10 months after the death of George Floyd sparked global racial justice protests.
After two weeks of jury selection, the prosecution began opening its case, arguing that the deadly encounter amounts to murder.
It is anticipated the jury will be shown a video of Chauvin with his knee on Mr Floyd's neck for nearly nine minutes during his arrest in May, after Mr Floyd, 46, allegedly used a fake $20 note at a store.
The footage was shared online and viewed by tens of millions of people, leading to protests and marches both in the the United States and across the world.
Prosecutors have not said when they will play the video but legal experts expect it to be early in the trial, as they seek to remind jurors of what is at the heart of their case, according to the Reuters news agency.
"If you're a prosecutor you want to start off strong. You want to frame the argument - and nothing frames the argument in this case as much as that video," said Jeffrey Cramer, a former federal prosecutor and managing director of the Berkeley Research Group in Chicago.
Mr Floyd was declared dead after Chauvin, 45, pressed his knee against Mr Floyd's neck for about nine minutes.
He stayed in that position even as Mr Floyd's "I can't breathe" cries faded and he went limp as he was handcuffed and lying on his stomach.
Chauvin is charged with unintentional second-degree murder, third-degree murder and manslaughter.
During a complex jury selection process, many of those chosen told Hennepin County District Judge Peter Cahill and the lawyers on each side that they recognised the scrutiny their deliberations would come under.
The trial is expected to last about four weeks and the courthouse in Minneapolis has been fortified with concrete barriers, fencing, and barbed wire.
City and state leaders are determined to prevent a repeat of riots that followed Mr Floyd's death and National Guard troops have already been mobilised.
The key questions at the trial will be whether Chauvin caused Mr Floyd's death and whether his actions were reasonable.
Philonise Floyd, brother of George Floyd, said before a church service that he had faith that prosecutors from the Minnesota attorney general's office would see Chauvin convicted.
"The video is the proof," he said.
The jury, including three alternates, is made up of six white women, three white men, three black men, one black woman and two mixed race women, according to court records.
“I'm thankful that it is a diverse jury,” Paris Stevens, a cousin of Floyd who works as a nurse in North Carolina, told the Associated Press in a telephone interview.
“I'm very anxious because you don't know what's going to happen, but I'm just glad that this process is starting.”
