Derek Chauvin is the second Minneapolis police officer to stand trial for murder in the last few years, but that is where the similarities end.

Former officer Mohamed Noor became the first policeman in recent state history to be charged with murder — and one of the few nationwide — after he fatally shot Justine Ruszczyk Damond while responding to her 911 call in 2017. Like Chauvin, Noor was fired from the department.

University of Minnesota sociology professor Michelle Phelps found herself glued to the Noor trial and is following the Chauvin proceedings with equally intense interest as opening statements begin Monday.

Already, the differences between the two cases are stark. For one thing, she says, this time around the city's police department seems to be on trial along with Chauvin, who faces murder and manslaughter charges in the death of George Floyd.

"I'm guessing that we'll see in the trial critiques of MPD more broadly," she said. "Activists have called for not just this criminal legal system response for the perpetrators, but also broader changes to prevent this from happening again."

Noor was convicted in Damond's death and ­sentenced to 12½ years in prison.

Floyd's death quickly became a watershed moment in the city's history, leading to widespread unrest, a state human rights investigation and calls to defund, or even abolish, the police department. It has also forced city leaders to confront the issues of race relations and police brutality head-on.

To retired Hennepin County Judge Pamela Alexander, the issue of race is as much a part of this case as it was the Noor trial, where a Black man born in Somalia was charged with killing a white Australian woman. More important, she said, it is impossible to view Floyd's death outside of the context of the long and painful history of police brutality against Black Americans.

"That's been going on for hundreds of years, whether or not people see it," Alexander said. "Who is going to be accountable for that?"

The charges against Noor came amid heightened scrutiny over deadly police encounters in places like Baton Rouge, La., Baltimore and Los Angeles. With the Chauvin case, Minneapolis again finds itself under a harsh international spotlight.

According to former Hennepin County Chief Public Defender Mary Moriarty, the trial will be closely watched by police reform advocates, for whom the Noor trial only highlighted a double standard in the criminal justice system that historically showed little interest in prosecuting white police officers who killed Black men.

"What they saw was a Black officer being really aggressively prosecuted for second-degree murder and other charges," said Moriarty, who has built a loyal following on Twitter with her minute-by-minute analysis of the Chauvin case.

"The comparison is really a slap in the face to our community, because what we see is white people who kill Black people get off," said Todd Gramenz, a leader of Black Lives Matter-St. Paul.

The two cases differ down to the descriptions of each victim killed, said defense attorney Paul Applebaum.

Prosecutors "had the benefit, in Noor's case, of somebody who had been angelized: She was a yoga teacher, she was an attractive middle-aged white woman, so that story wrote itself," said Applebaum, pointing out that the defense intends to focus its counterattack on Floyd's past drug use and brushes with the law. "It's a tougher sell when you try to humanize someone like Floyd who had his issues, who had a background, and those are all things that people shouldn't take into account, but they do."

In the Chauvin case, state Attorney General Keith Ellison made the unprecedented decision to take the lead in the prosecution from the Hennepin County Attorney's Office, which had secured a conviction of Noor, but had previously faced criticism for failing to charge other officers who used deadly force.

There is another important way the Noor case has loomed over the current trial, which in a first for the state is livestreamed for the world to see. The Noor trial included pretrial debate about whether someone can be convicted of third-degree murder if their deadly act is aimed at a single person and whether the reckless nature of the act alone can establish a "depraved" mind-set. The state Supreme Court has agreed to hear Noor's appeal of his third-degree murder conviction, which could have implications for the Chauvin case.

Other differences are less obvious. For instance, prosecutors in the Chauvin case have not faced the same lack of cooperation from potential officer witnesses, who in the lead-up to the Noor trial refused repeated requests to provide pretrial statements on the union's advice, forcing the county attorney's office to issue dozens of subpoenas.

Michael Friedman, who previously served on a police disciplinary review panel, said that while fatal police shootings are comparatively rare, Chauvin's actions reminded him of "the most common reason for excessive force that I saw — was not responding to someone who was physically challenging, but what I would call retaliatory control."

He noted examples like when someone flees police, or they are resisting authority or what was alleged in Floyd's case, that he refused to be brought into the squad car. Friedman said such instances can bring out a certain mentality among many officers, particularly of the earlier generation, that they pile on force as a means of retaliation to maintain control.

Legal analysts and early court filings suggest that cause of death will be a central theme in the Chauvin case. Whereas even Noor's defense team acknowledged that he shot Damond because he feared for his life after she approached the squad car, attorneys for Chauvin have signaled their intent to concentrate on Floyd's past drug use and underlying health conditions. The defense is arguing that these other factors resulted in his death — not Chauvin's knee. The presiding judge has said that for the second-degree murder charge, prosecutors must prove only that Chauvin's conduct was a "substantial causal factor" in Floyd's death.

Throughout the Noor trial, prosecutors sought to paint him as an undisciplined rookie who had violated his training at the Police Academy. They also released parts of his field training evaluations, showing that some of his superiors had concerns about his conduct, fueling online chatter that the department had lowered its standards in hiring Noor — characterizations that his backers rejected as racist stereotypes.

"There was a lack of training on Noor's part, and he could not point to any training that he did, but with Chauvin — as freaky and grotesque as it sounds — he's going to say, this is what we were taught to do," said Applebaum, the defense attorney.

Chauvin's defense attorneys have argued in pretrial motions and other filings that the use of force followed the department's then-policy on dealing with uncooperative suspects. Shortly after Floyd's death, Minneapolis police changed its use-of-force policy to prohibit the use of chokeholds and neck restraints — like the one Chauvin used on Floyd — under a deal negotiated between the city and the state.

Greg Hestness, a former MPD deputy chief, said that all officers who use deadly force are judged by the standard of what a "reasonable officer" would do in similar circumstances. But, he said, Chauvin's actions will be judged by a different standard than in Noor's case, which involved a firearm, in part because shootings involve split-second decisions that juries are more reluctant to second-guess.

"The Noor case was just a reckless discharge of a firearm that took a life. Chauvin's acts were not sort of knee-jerk, it wasn't a quick reaction, there were eight to nine minutes there," said Hestness, adding that no footage exists of Damond's killing, but prosecutors will rely on the widely seen bystander video of Chauvin kneeling on Floyd's neck. "I mean, to this day, I don't know what he was doing kneeling on that man for eight to nine minutes."

This story is part of a collaboration with the PBS series "Frontline," through its Local Journalism Initiative, which is funded by the John S. and James L. Knight Foundation and the Corporation for Public Broadcasting.