The judge overseeing the trial of a former Minneapolis police officer accused over the death of George Floyd has paused jury selection for at least a day while an appeal proceeds over the possible reinstatement of a third-degree murder charge.

As hundreds of protesters gathered outside the courthouse to call for the conviction of Derek Chauvin, Judge Peter Cahill said he does not have jurisdiction to rule on whether the third-degree murder charge should be reinstated against the former officer while the issue is being challenged.

But he said prosecutors’ arguments that the whole case would be impacted was “tenuous”.

Judge Cahill initially ruled that jury selection would begin as scheduled on Monday, but prosecutors said they would ask the Court of Appeals to intervene, which could put the case on hold, so the judge sent the potential jurors home for the day.

Chauvin is charged with second-degree murder and manslaughter over Mr Floyd’s death.

Legal experts say reinstating the third-degree murder charge would improve the odds of getting a conviction.

Chauvin’s lawyer Eric Nelson said on Monday he would ask the state Supreme Court to review a Court of Appeals decision that ordered Judge Cahill to reconsider the charge.

Former Minneapolis police officer Derek Chauvin
Former Minneapolis police officer Derek Chauvin (Ramsey County Sheriff’s Office via AP)

Jury selection is expected to take at least three weeks, as prosecutors and defence lawyers try to weed out people who may be biased against them.

“You don’t want jurors who are completely blank slates, because that would mean they’re not in tune at all with the world,” Susan Gaertner, a former prosecutor, said.

“But what you want is jurors who can set aside opinions that have formed prior to walking into the courtroom and give both sides a fair hearing.”

Mr Floyd was declared dead on May 25 after Chauvin, who is white, pressed his knee against the handcuffed black man’s neck for about nine minutes, holding his position even after Mr Floyd went limp.

Mr Floyd’s death sparked sometimes violent protests in Minneapolis and beyond, and led to a nationwide reckoning on race.

Demonstrators gather outside the Hennepin County Government Centre in Minneapolis
Demonstrators gather outside the Hennepin County Government Centre in Minneapolis (Jim Mone/AP)

Chauvin and three other officers were fired; the others face an August trial on aiding and abetting charges.

Hundreds of people gathered outside the courthouse as proceedings began, many carrying signs that read: Justice for George Floyd and Convict Killer Cops.

One speaker took a microphone and decried the barricades – concrete barriers topped by chain-link fencing, barbed wire and razor wire – set up around the courthouse.

He also ridiculed talk of the Chauvin trial as “the trial of the century”, saying all the jury needs to do is “do the right thing”.

Then he led the crowd in chants of “The whole world is watching!”

Inside the courtroom, Chauvin, in a blue suit and black mask, followed the proceedings attentively, making notes on a legal pad.

Mr Nelson earlier argued that pre-trial publicity of the case and the subsequent violent unrest in Minneapolis would make it impossible to find an impartial jury in Hennepin County.

But Judge Cahill said last year that moving the trial would probably not cure the problem of a potentially tainted jury pool because “no corner of the state of Minnesota” has been shielded from pre-trial publicity.

Hennepin County Judge Peter Cahill presides over a hearing before jury selection at the Hennepin County Courthouse in Minneapolis, Minnesota
Hennepin County Judge Peter Cahill (Court TV/Pool via AP)

The potential jurors – who must be at least 18, US citizens and residents of Hennepin County – were sent questionnaires to determine how much they have heard about the case and whether they have formed any opinions.

Besides biographical and demographic information, jurors were asked about prior contacts with police, whether they have protested against police brutality and whether they believe the justice system is fair.

Some of the questions get specific, such as how often a potential juror has watched the bystander video of Mr Floyd’s arrest, or whether they carried a sign at a protest and what that sign said.

Mike Brandt, a local defence lawyer, said prosecutors will be likely to seek out jurors who have favourable opinions on the Black Lives Matter movement or might have more outrage over Mr Floyd’s death, while Chauvin’s lawyers would be likely to favour jurors who support the police.

Unlike typical jury selection proceedings, potential jurors will be questioned individually rather than in a group.

The judge, defence lawyer and prosecutors will all get to ask questions.

The defence can object to up to 15 potential jurors without giving a reason; prosecutors can block up to nine without providing a reason.

Either side can object to these peremptory challenges if they believe the sole reason for disqualifying a juror is race or gender.

Demonstrators gather outside the Hennepin County Government Centre in Minneapolis
Demonstrators outside the Hennepin County Government Centre (Jim Mone/AP)

Both sides can also argue to dismiss an unlimited number of jurors “for cause”, meaning they must provide a reason why they believe that juror should not serve.

Those situations can get into some detailed machinations, Mr Brandt said, and it is up to the judge to decide whether a juror stays or goes.

“Sometimes there is some tortured questioning,” he said.

Mr Brandt said that even if a juror says they have had a negative interaction with the police, or a negative opinion about Black Lives Matter, the key will be trying to find out whether they can put those past experiences or opinions aside and be fair.

“We all walk into these with biases. The question is, can you put those biases aside and be fair in this case,” he said.

Jury selection will end after 14 people are picked – 12 jurors who will deliberate the case and two alternates who will not be part of deliberations unless needed.

The jurors will be escorted to the courthouse daily and sequestered during deliberations.

Their names will be kept confidential until further order of the court.

Billy Briggs, who lives just 170 steps from where George Floyd was killed, created and maintains the countdown sign at the gas station on the corner of George Floyd Square in Minneapolis, Minnesota
Billy Briggs created and maintains the countdown sign at the petrol station on the corner of George Floyd Square in Minneapolis (Jeff Wheeler/Star Tribune via AP)

The number of seats in the courtroom has been limited to maintain social distancing due to the Covid-19 pandemic, and seats for jurors have been spaced out.

Like others in the courtroom, jurors will be required to wear masks.

The earliest that opening statements will begin is March 29.