Washington (AFP) - A jury began deliberations on Tuesday in the racially charged trial of three white men accused of murder in the southern US state of Georgia for shooting dead a Black man after chasing him in their pickup trucks.

Gregory McMichael, 65, a retired police officer; his son Travis, 35; and their neighbor William "Roddie" Bryan, 52, are facing a sentence of potential life in prison for the February 2020 shooting of 25-year-old Ahmaud Arbery.

"Start your deliberations with an open mind," Judge Timothy Walmsley told the predominantly white jury at the conclusion of the month-long trial. "Each of you must decide this case for yourself."

A graphic video of the shooting of the unarmed Arbery went viral on social media and added fuel to last year's protests against racial injustice sparked by the murder of George Floyd, a 46-year-old Black man, by a white police officer in Minnesota.

The defendants have said they suspected Arbery was a burglar who had been active in their neighborhood and invoked a since-repealed state law that allows ordinary citizens to make arrests.

But chief prosecutor Linda Dunikoski said they had no justification for attempting to detain Arbery and never told him they were trying to arrest him as he jogged through their Satilla Shores neighborhood on a Sunday afternoon.

"You can't make a citizen's arrest because somebody's running down the street," Dunikoski said in her final statement on Tuesday.

"This isn't the Wild West," she said. "You can't just stop someone in the United States of America. People are free here."

The prosecutor said the McMichaels, who were armed with a shotgun and a handgun, and Bryan, who was unarmed, didn't see Arbery commit any crime that day but "chose to confront him."

"He was trying to get away from these strangers who were yelling at him, threatening to kill him," Dunikoski said. "And then they killed him."

During her closing arguments, the prosecutor said the McMichaels made the decision to go after Arbery simply "because he was a Black man running down the street."

'Acting funny'

The jury was shown video during the trial of the McMichaels pursuing Arbery in their truck, and Bryan chasing him in his own vehicle while filming the scene on his cell phone.

At one point, Arbery attempts to run around the front of the McMichaels' stopped truck.

Travis McMichael, who had gotten out of the vehicle, opens fire with a 12-gauge shotgun. A wounded Arbery is seen struggling with McMichael before being killed by another shot.

On the witness stand, Travis McMichael testified that he thought Arbery was the man he had seen several days earlier in a house on their street that was under construction.

He said Arbery did not display a weapon or threaten him in any way as they drove alongside him but was "acting weird." "He was acting funny," McMichael said.

McMichael said he repeatedly tried to talk to the running Arbery through the car window, but he refused to answer and "stopped, turned and went the other direction."

He said Arbery grabbed for his shotgun, and that he shot him in self-defense.

Dunikoski, the prosecutor, rejected that argument telling the jury "you can't claim self-defense if you are the unjustified initial aggressor."

'Justice for Ahmaud'

Speaking to reporters after the jury began deliberations, Wanda Cooper-Jones, Arbery's mother, said she believed they "will come back with a guilty verdict."

"We will get justice for Ahmaud," she said.

There is only one Black juror on the 12-member jury hearing the case, although about 25 percent of the 85,000 residents of Glynn County, where the trial is taking place, are Black.

Kevin Gough, Bryan's attorney, sought on several occasions during the trial to have the judge declare a mistrial, claiming the presence of civil rights leaders Al Sharpton and Jesse Jackson in the gallery was influencing the jurors.

Judge Walmsley dismissed the motions, saying anyone was welcome to attend the trial so long as they were not disruptive.

The jury began deliberations just days after the acquittal of Kyle Rittenhouse in another closely watched case.

Rittenhouse, 18, shot dead two men and wounded another during protests and riots against police brutality in Wisconsin last year that followed the police shooting of a Black man.

The teen claimed self-defense and was acquitted of all charges on Friday.