MINNEAPOLIS -- Jury selection for a former Minneapolis police officer charged in George Floyd's death was halted before it began Monday by the state's effort to add a third-degree murder charge.

As hundreds of protesters rallied outside the courthouse to call for Derek Chauvin's conviction, Judge Peter Cahill said he did not have jurisdiction to rule on whether the third-degree murder charge should be reinstated while the issue is being appealed.

Cahill initially ruled jury selection would begin as scheduled, but after prosecutors asked the Court of Appeals to put the case on hold, the judge sent the potential jurors home for the day and the rest of the day was spent ruling on motions. Cahill later said jury selection would resume Tuesday barring an order from the appellate court.

There was no indication when that court will rule, but a hold could delay Chauvin's trial for weeks.

Prosecutors and defence attorneys agreed to dismiss 16 of the first 50 jurors they reviewed "for cause" based on their answers to a lengthy questionnaire. These dismissals weren't debated in court, but can happen for a host of reasons, such as views that indicate a juror can't be impartial.

Chauvin is charged with second-degree murder and manslaughter in Floyd's death. The Court of Appeals last week ordered Cahill to consider reinstating a third-degree murder charge that he had dismissed. Legal experts say reinstating the charge would improve the odds of getting a conviction. Chauvin's attorney, Eric Nelson, said Monday he would ask the state Supreme Court to review the issue.

For the unintentional second-degree murder charge, prosecutors have to prove Chauvin's conduct was a "substantial causal factor" in Floyd's death, and that Chauvin was committing felony assault at the time. For third-degree murder, they must prove that Chauvin's actions caused Floyd's death, and that his actions were reckless and without regard for human life.

Floyd was declared dead May 25 after Chauvin, who is white, pressed his knee against the Black man's neck for about nine minutes, holding his position even after Floyd went limp. Floyd's death sparked sometimes violent protests in Minneapolis and beyond, and led to a nationwide reckoning on race.

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, DJ Hooker, took a microphone and decried the concrete barriers topped by chain-link fencing, barbed wire and razor wire set up around the courthouse, and ridiculed talk of the Chauvin trial as "the trial of the century," saying the jury simply must "do the right thing."

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. No one attended to support him. Bridgett Floyd, George Floyd's sister, sat in the seat allocated to Floyd's family.

Afterward, Floyd said her family is glad the trial has finally arrived and is "praying for justice."

"I sat in the courthouse today and looked at the officer who took my brother's life," she said. "That officer took a great man, a great father, a great brother, a great uncle."

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

Jurors must be at least 18, U.S. citizens and residents of Hennepin County. Potential jurors were sent questionnaires to determine how much they have heard about the case and whether they've 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 Floyd's arrest, or whether they carried a sign at a protest and what that sign said.

Potential jurors will be questioned individually. The judge, defence attorney and prosecutors can all ask questions. In addition to both sides being able to argue for an unlimited number of "for cause" dismissals, 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.

Some jurors could remain on the panel, even if they have had a negative interaction with the police or hold negative views about Black Lives Matter, local defence attorney Mike Brandt said.

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

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

The earliest opening statements will begin is March 29.

------

Associated Press writer Mohamed Ibrahim contributed this report.