By Eric Levenson, CNN

(CNN) -- The death that sparked a worldwide movement will take center stage in a heavily fortified Minneapolis courtroom as jury selection is set to begin in Derek Chauvin's trial in the death of George Floyd.

Floyd, a 46-year-old Black man, died on May 25, 2020, after Chauvin, then a Minneapolis Police officer, placed his knee on Floyd's neck for nearly eight minutes while Floyd pleaded, "I can't breathe." His final moments were captured on video, and his death led to widespread protests against police brutality and racism under the banner Black Lives Matter as well as incidents of unrest and looting.

Chauvin has pleaded not guilty to second-degree unintentional murder and second-degree manslaughter charges. In addition, a charge of third-degree murder that was dismissed in October is now in limbo after an appeals court ruled the trial judge should reconsider a motion to reinstate it.

Jury selection in the trial was delayed from Monday to Tuesday at the Hennepin County Government Center as the court tries to decide how to proceed with that appeal pending. Once it begins, jury selection is expected to last about three weeks. Opening statements are expected to start no earlier than March 29, followed by testimony over the next two to four weeks.

How jury selection will go

In a case with so much media attention, it may be impossible to find a jury that hasn't heard about Floyd's death. But the goal is not to find ignorant people; it's to find jurors who can be impartial and are open to hearing the evidence and the law.

"No matter what a potential juror has seen or heard, can they set that aside and base their decision on evidence in court and the law the judge gives them?" said Mary Moriarty, the former chief Hennepin County public defender.

In December, prospective jurors were sent a 16-page questionnaire asking for their thoughts on Black Lives Matter protests, their views on policing and their personal interactions with police.

Starting Monday, some prospective jurors who completed the questionnaire will be questioned one-by-one in court in a process known as voir dire. The juror's name, address and other information will be kept anonymous.

The judge will first ask questions of the prospective juror, followed by the defense and then the prosecution. If the defense or prosecution believes the person cannot be impartial in the case, they can ask the court to dismiss the person for cause. Each side has unlimited challenges for cause.

Prosecutors and defense attorneys can also move to dismiss prospective jurors without cause using what's called a peremptory challenge. Chauvin's team has 15 of these challenges and the prosecution has nine, according to the court.

These peremptory challenges can themselves be challenged, though, if they are based on race, ethnicity or sex -- known as a Batson challenge.

The process continues until the court decides on up to 16 people, split into 12 jurors and up to four alternates.

Who's who in the trial

George Floyd, 46, was born in North Carolina and raised in Houston and moved to Minnesota as an adult for a fresh start, working as security at a restaurant.

On May 25, 2020, police were called about a man who had used a $20 counterfeit bill at a Minneapolis store. Officers were directed to a parked car with Floyd in the driver's seat, and they handcuffed him and moved to put him into the back of a police car, according to the amended complaint.

Two other officers, including Chauvin, then responded to the scene and struggled to get Floyd into the vehicle, the complaint states. Chauvin allegedly pulled Floyd to the ground in a prone position and placed his knee on Floyd's neck and head. His knee remained there even as Floyd pleaded, "I can't breathe," said "I'm about to die" and ultimately stopped breathing, the complaint says. He was pronounced dead at a hospital shortly after.

The Hennepin County Medical Examiner's autopsy listed the cause of death as heart failure "complicating law enforcement subdual, restraint, and neck compression," and ruled it a homicide. The medical examiner also noted arteriosclerotic and hypertensive heart disease; fentanyl intoxication; and recent methamphetamine use as "other significant conditions."

Medical examiners hired by Floyd's family also ruled it a homicide but said Floyd died of "asphyxiation from sustained pressure" during the arrest.

Derek Chauvin, 44, had been an officer with the Minneapolis Police Department since 2001 until he was fired in the wake of Floyd's death. He was the subject of at least 18 prior complaints, two of which were "closed with discipline," according to a department internal affairs public summary.

A motion to dismiss the charges filed last August previewed his possible defense. In that filing, his attorney argued that Chauvin had no intent to harm Floyd while restraining him, that he was acting within police policy, and that Floyd's cause of death was the result of a drug overdose and other existing health issues.

Thomas Lane, J. Alexander Kueng and Tou Thao, all former Minneapolis Police officers, were also on scene with Chauvin and are charged with aiding and abetting second-degree murder and aiding and abetting second-degree manslaughter. They have pleaded not guilty.

Due to limits on courtroom space because of the pandemic, their joint trial was moved to this summer. They will not testify in Chauvin's trial, but their names, statements and actions will be heavily featured.

Eric Nelson is Chauvin's defense attorney and will represent him at trial. He is part of the Halberg Criminal Defense practice and has worked exclusively in criminal defense since being admitted to the bar, according to his online bio.

Minnesota Attorney General Keith Ellison's office says the three main presenting prosecution attorneys are Jerry Blackwell, Matthew Frank, and Steve Schleicher.

Peter Cahill is the Hennepin County judge overseeing the case. He was first appointed to the bench in 2007 and has been reelected to the position three times since, most recently last November.

An explanation of the charges

Chauvin is charged with second-degree unintentional murder and second-degree manslaughter.

The second-degree unintentional murder charge alleges that Chauvin killed Floyd "without intent" while he committed or attempted to commit felony third-degree assault, which is defined as inflicting "substantial" bodily harm. The charge is punishable by up to 40 years in prison.

The second-degree manslaughter charge alleges that Chauvin caused Floyd's death by "his culpable negligence, creating an unreasonable risk and consciously took the chances of causing death or great bodily harm." "Culpable negligence" is essentially a heightened form of ordinary negligence, Moriarty explained. The charge is punishable by up to 10 years in prison.

An earlier charge of third-degree murder was dismissed in October as the judge ruled it did not apply to this case. The Minnesota Court of Appeals ruled Friday that the judge should reconsider the state's motion to reinstate the third-degree murder charge.

On Monday, the state moved to stop jury selection until the appeal is resolved, but Judge Cahill ruled against doing so. The state then moved to appeal that ruling, so Cahill moved the start of jury selection to Tuesday to see whether the court can proceed.

How the pandemic changed the trial

The possibility of a courtroom Covid-19 outbreak looms, so the court has taken a number of steps to prevent one.

Everyone who attends the Chauvin trial will be required to distance from others and wear a mask, although witnesses and attorneys may remove their masks during testimony and other court statements. Plexiglass has been installed around the courtroom as well.

In addition, the trial will be livestreamed for those not able to attend, a first for a Minnesota criminal trial.

Only one member of Floyd's family and Chauvin's family will be allowed to attend the trial because of the Covid-19 restrictions. For each family, a different family member can rotate through that in-court position with appropriate credentials, the judge ruled.

During the trial, the jurors will be partially sequestered during the day but will be allowed to return to their homes at night. They will be fully sequestered during deliberations.

How police are preparing

Given the unrest and looting that ensued when Floyd died, local and state authorities are taking major security measures. The Hennepin County Government Center is now surrounded by fencing and barricades, and the building will be empty aside from those participating in Chauvin's trial and approved staff.

Mayor Jacob Frey said the city is preparing for potential unrest with "painstaking detail." He said up to 2,000 National Guard members will be prepared to respond along with up to 1,100 law enforcement pooled from 12 other jurisdictions.

"Safety is a top priority through this very difficult time in our city," Frey said last month. "There's great frustration, there's anxiety, and there's trauma. We anticipate that trauma increasing as we get closer to jury deliberations."

Minnesota law enforcement leaders last month outlined their plan to work together to provide security during the trial in what they called "Operation Safety Net."

State Patrol Col. Matt Langer said the goal is to protect lawful protests and demonstrations while preventing violence, property damage, fires and looting.

"Planning for this operation occurred starting back in July," Langer said. "It occurred in earnest all summer."

Operation Safety Net is organized into four phases, according to Langer: (1) Planning and preparation, (2) jury selection; (3) closing arguments, deliberations and a verdict; and (4) demobilization.

Minneapolis Police Chief Medaria Arradondo said the unified command will help everyone stay on the same page.

"It will allow all of us to be able to respond metro and region wide, if needed, and it will allow great cooperation coordination and communication," he said.

Minnesota Department of Public Safety Commissioner John Harrington said last month the actions were all precautionary.

"As of right now, we do not have any current, actionable intelligence about groups planning to come here to disrupt the trial or to cause disorder," Harrington said. "We are exercising this unified command out of caution."