Impartiality of juror in George Floyd murder trial questioned
A mural and memorial to George Floyd in Minneapolis, Minnesota, at the site where he died(AFP)

The impartiality of a juror who convicted former Minneapolis police officer Derek Chauvin of the murder of George Floyd has come into question after a photo surfaced of him at an anti-racism rally.

Legal experts said Chauvin's defense attorney could potentially use the photo of juror Brandon Mitchell as grounds to appeal the verdict.

In the photo Mitchell, a Black 31-year-old, is wearing a T-shirt with a picture of civil rights leader Martin Luther King Jr on it and the words "Get Your Knee Off Our Necks" and the letters "BLM" for Black Lives Matter.

Chauvin, who was captured on video kneeling on Floyd's neck for more than nine minutes, was convicted of murder and manslaughter last month by a 12-member jury.

Mitchell is one of only two jurors who have publicly identified themselves since the high-profile trial.

In a questionnaire, potential jurors were asked if they had taken part in any of the protests against police brutality which followed Floyd's May 25, 2020 death.

Mitchell said he had not and could serve impartially. He told the Minneapolis Star Tribune that the photo was taken at a march he attended in Washington in August 2020 to mark the anniversary of Martin Luther King's famous "I Have a Dream" speech.

Jeffrey Frederick, a jury selection expert, said Mitchell's answer may be "technically correct" since the Washington event was billed as a commemoration.

"It'll be up to the judge to conduct questioning and to make a determination as to whether or not he felt that this juror was biased and, possibly, had lied during the course of voir dire or on the juror questionnaire," Frederick told AFP.

The judge would then decide whether it "reaches a standard for affecting the outcome of the trial," he said.

"The bar is high in terms of misconduct and the granting of a new trial," he added. "Such determinations are rare."

Steve Tuller, another jury selection expert, agreed.

"Judges do not want to declare mistrials, particularly in a case where there has been a verdict and given the special circumstances of this case," Tuller said.

"In the end, I think it's unlikely that the juror's 'revelation' will change the verdict."

Chauvin is to be sentenced on June 25 and faces up to 40 years in prison on the most serious charge -- second-degree murder.