Prosecutors on Friday said the three white men accused of murdering Ahmaud Arbery in Georgia last year placed the 25-year-old Black man under a sustained “attack” and made a series of “assumptions and driveway decisions” that led to shooting him dead. During highly charged opening statements in the closely watched trial, now infamous cellphone video of the shooting was played to the court. Arbery’s mother, Wanda Cooper-Jones, broke down in tears. The video shows Travis McMichael opening fire three times on Arbery, who was unarmed, with a Remington 12-gauge pump-action shotgun. The shooting happened in February 2020, on a quiet street in rural south Georgia, as McMichael, his father and co-defendant Gregory McMichael and a neighbor, William “Roddie” Bryan, attempted to block Arbery, who was on foot, by pursuing him in two vehicles. Arbery, who was known to go jogging in the area, was described by prosecutors as “an avid runner”. The jury was told that evidence would show that the McMichaels had wrongly assumed the 25-year-old was attempting a burglary at a house under construction in the Satilla Shores neighbourhood. “This was an attack on Mr Arbery for five minutes, and the only thing Mr Arbery did was try to run away,” lead prosecutor Linda Dunikoski told the jury of 11 white members and one Black member. The three defendants have pleaded not guilty to charges of murder, aggravated assault and criminal attempt to commit false imprisonment, in a case thrust into the global spotlight. During detailed opening arguments, Dunikoski told the jury Gregory McMichael informed police after the shooting that he called out to Arbery during the pursuit, “Stop or I’ll blow your fucking head off”, and also told police Arbery had been “trapped like a rat” during their five-minute chase. “We are here because of assumptions and driveway decisions,” Dunikoski said as the three defendants looked on. “A very wise person once said, do not assume the worst of another person’s intentions until you actually know what’s going on with them.” She added: “And in this case, all three of these defendants did everything that they did based on assumptions. And they made decisions in their driveways based on assumptions that took a young man’s life and that’s why we are here.” Dunikoski played videos of Arbery inside the under-construction house dating back to late August 2019, in an attempt to show he had routinely run through the neighborhood and stopped off at the house without stealing anything. The McMichaels’ fatal pursuit of Arbery occurred on 23 February 2020. Dunikoski also played a 911 emergency call Gregory McMichael made to police before Arbery was shot, in which he said: “I’m here in Satilla Shores. A Black male is running down the street.” The prosecutor said evidence would show the McMichaels initially pursued Arbery in their white truck before driving ahead in an attempt to close him off, while Bryan attacked Arbery by ramming him in a separate truck four times. Prosecutors said evidence would show a palm print of Arbery’s on Bryan’s vehicle as well as white T-shirt fibres belonging to Arbery on the truck. Arbery was cornered by the three men, and Travis McMichael pointed his shotgun before opening fire as Arbery continued to run. Shortly after Dunikoski concluded her statements, Bryan’s attorney, Kevin Gough, argued that the presiding judge, Timothy Walmsley, should declare a mistrial because details of the initial investigation into the shooting were disclosed during the opening. Walmsley declined. During defense opening arguments, lawyers for Travis McMichael argued he acted in self-defense when he opened fire, and cited a citizen’s arrest law that was revoked in response to the incident. Robert Rubin, the younger McMichael’s lawyer, argued his client had been attempting to “de-escalate” the situation when he raised his shotgun and that he opened fire when he feared for his and his father’s life. “It is a citizen’s job to help the police and the law authorizes that,” Rubin told the court. “When seconds count, the police are often minutes away. The police are not going to catch this guy at the speed he’s running.” Georgia’s response to Arbery’s killing has become part of a broader effort to address racial injustice in the US legal system after a string of fatal encounters between police and Black people such as George Floyd in Minnesota and Breonna Taylor in Kentucky. Judge Walmsley swore in the disproportionately white jury on Friday. Although Glynn county, where the court is located, has an African American populationof 26%, the jury pool was whittled down until only one Black person was seated. Defense attorneys struck 11 Black potential jurors, an outcome the judge criticized. Abery’s mother called the imbalance in the jury “devastating”. The trial continues.