The closely watched trial of Derek Chauvin, the former Minneapolis police officer charged with murder in George Floyd’s death, entered a key phase Monday as the prosecution and defence delivered their opening statements and the first witnesses were called to testify.

Both sides focused on the cause of Floyd’s death in their opening arguments, taking vastly different positions on the matter. In his roughly one-hour opening remarks, attorney Jerry Blackwell, who is assisting with the state of Minnesota’s prosecution, dismissed a claim pushed by the defence that drugs played a major role in Floyd’s death.

“George Floyd struggled with an opioid addiction,” Blackwell said. “He struggled with it for years. … He did not die from a drug overdose. He did not die from an opioid overdose.”

Blackwell argued that Floyd would not have been communicating during his arrest were he suffering from a drug overdose at the time. Instead, Floyd’s death was a direct result of Chauvin’s use of force, he said.

Chauvin “was well aware that Mr Floyd was unarmed, that Mr Floyd had not threatened anyone, that Mr Floyd was in handcuffs; he was completely in the control of the police,” Blackwell said.

Two autopsies ― one conducted by county officials and the other commissioned by Floyd’s family ― separately classified Floyd’s death as a homicide. However, the autopsy reports, which were both released last June, differed on the exact cause of death.

The Hennepin County Medical Examiner’s Office said in its report that Floyd died of “cardiopulmonary arrest complicating law enforcement subdual, restraint and neck compression.” The report also noted that fentanyl and methamphetamine were found in Floyd’s system upon his death. 

Chauvin’s attorney, Eric Nelson, took roughly 30 minutes to deliver his opening statement, in which he urged the jurors to use “common sense” and “reason” while listening to witnesses and reviewing the evidence.

Nelson argued that the evidence showed Floyd died of “cardiac arrhythmia that occurred as a result of hypertension, coronary disease, the ingestion of methamphetamine and fentanyl and the adrenaline flowing through his body.”

Floyd, 46, died on May 25, 2020, after three police officers, including Chauvin, pinned him facedown on the ground outside a convenience store. Store clerks had called 911 minutes earlier and accused Floyd of using a $20 counterfeit bill.

Bystander video recorded on a cellphone and viewed millions of times around the world showed Chauvin, who is white, kneeling on Floyd’s neck as Floyd, who is Black, repeatedly stated that he couldn’t breathe.

Floyd’s death sparked months of nationwide protests against police brutality and resulted in a worldwide reckoning with racial injustice.

Chauvin has been charged with second-and-third-degree murder as well as second-degree manslaughter. He has pleaded not guilty to all charges.

Due to Covid-19 concerns, Hennepin County District Judge Peter Cahill has limited courtroom attendance but has made the extraordinary decision to allow the trial to be broadcast live.

Chauvin, 45, could be seen listening and taking notes on a legal pad during the opening remarks and witness testimonies. 

Following opening arguments, the prosecution called its first witness to the stand: Jena Scurry, a 911 dispatcher for the city of Minneapolis. She had been monitoring Floyd’s arrest via a police surveillance camera and alerted a police sergeant to voice her concerns about what she was seeing.

“My instincts were telling me that something was wrong,” Scurry testified. “It was a gut instinct in the incident, something is not going right.”

Alisha Oyler, 23, was the second witness called to testify. She was working at the Speedway gas station when Floyd was arrested across the street. Minnesota Assistant Attorney General Matthew Frank showed video she recorded on her cellphone of the arrest from inside the gas station. Oyler said she had trouble recalling much of what she witnessed that day and became visibly flustered at one point.

Prosecutors called their third and final witness of the day around 3:30pm local time. Donald Williams II testified that he had been walking to Cup Foods, the store that reported Floyd for using the counterfeit bill, to buy a drink when he heard a commotion nearby.

Williams said he then noticed Floyd being arrested and watched as Chauvin knelt on the man’s neck. Williams, who said that he was a trained mixed martial artist, said he witnessed Chauvin using a “blood choke” on Floyd, which he said “hinders” a person’s blood flow and can be deadly.

Williams said he called out to Chauvin as he was kneeling on Floyd and accused him of using the move. 

“He looked at me,” Williams testified, adding that Chauvin stared at him “dead in the eyes” at that point. “That’s the only time he looked up.”

Minutes later, several live broadcasts of the trial cut out and displayed the words “no signal” on the feed. However, Court TV’s broadcast continued to air video of the proceedings and Cahill could be heard telling the jurors that there was a technical glitch. He then dismissed them for the day.

The trial is being held in the 18th-floor courtroom of the Hennepin County Government Center in downtown Minneapolis. Metal fencing has been erected around the building in anticipation of protests during and after the high-profile trial. National Guard troops could be seen Monday guarding the perimeter. 

As the trial unfolded Monday, roughly a dozen protesters, some holding Black Lives Matter flags, attempted to block traffic outside the building. 

Carolyn Ruff, co-founder of Black Lives Matter Women of Faith in Chicago, joined the protesters in the street.

“If he’s not convicted, I feel sorry for America,” Ruff told HuffPost. “We want a conviction. He killed a human being. It’s only right that he be convicted. He’s not above the law.”

“This is the way America treats Black people,” she said of instances of police brutality. “And you know, it’s really sad because … we built this country. All we want is respect.”

Members of Floyd’s family and their attorneys gathered outside the government centre earlier Monday ahead of the opening arguments to speak to a small crowd of reporters and supporters.

“Today starts a landmark trial that will be a referendum on how far America has come in its quest for equality and justice for all,” said Ben Crump, an attorney for Floyd’s family. “This trial will prove if we live up to the belief that all men are created equal.”

Adam Goldberg contributed reporting from Minneapolis.

This is a developing story. Please check back for updates.