Attorney General Keith Ellison's office on Wednesday upgraded charges against the former Minneapolis police officer who knelt on George Floyd's neck and charged the other three officers at the scene with aiding and abetting murder.

The decision came just two days after Ellison took over the prosecution from Hennepin County Attorney Mike Freeman and followed more than a week of sometimes-violent protests calling for tougher charges against former Minneapolis police officer Derek Chauvin, who had pinned Floyd to the ground and held him there for nearly nine minutes. Protesters also demanded the arrests of the three other former officers who were present but failed to intervene. All three were booked into the Hennepin County jail on Wednesday.

"To the Floyd family, to our beloved community, and everyone that is watching, I say: George Floyd mattered. He was loved. His life was important. His life had value. We will seek justice for him and for you and we will find it," Ellison said

However, he said, he doesn't believe that "one successful prosecution can rectify the hurt and loss that so many people feel. The solution to that pain will be in the slow and difficult work of constructing justice and fairness in our society."

Chauvin, who was recorded on video kneeling on Floyd's neck as he begged for air on Memorial Day, now faces the more serious charge of second-degree murder, in addition to the original charges of third-degree murder and second-degree manslaughter with culpable negligence.

Chauvin was originally charged by the Hennepin County Attorney's Office last week.

The amended complaint filed against Chauvin stated, "Police are trained that this type of restraint with a subject in a prone position is inherently dangerous. … Officer Chauvin's restraint of Mr. Floyd in this manner for a prolonged period was a substantial factor in Mr. Floyd losing consciousness, constituting substantial bodily harm, and Mr. Floyd's death as well."

Don Lewis, special prosecutor in the case against Jeronimo Yanez, the former St. Anthony police officer who killed Philando Castile in 2016, said the nearly nine-minute recording of the moments before Floyd died showed ample evidence of intent to kill on Chauvin's part.

"Those are moments to cause reflection on whether or not you're in the middle of a wrongful death here," Lewis said. "You have George Floyd begging for his life, right? 'I can't breathe.' This is a moment of potential reflection on Chauvin's part," Lewis said. "He had multiple opportunities to change course here and decided not to over the span of almost 10 minutes."

The other officers at the scene — Tou Thao, J Alexander Kueng and Thomas Lane — were each charged with aiding and abetting second-degree murder while committing a felony, and with aiding and abetting second-degree manslaughter with culpable negligence. Both charges are categorized as "unintentional" felonies.

Thao was recorded watching as Chauvin continued to press on Floyd's neck with his knee. Kueng was one of the first officers on the scene and helped pin Floyd down. Lane was detailed in earlier charges as pointing a gun at Floyd before handcuffing, and he later asked whether officers should roll Floyd on his side as he was restrained.

The charges come just days after Gov. Tim Walz asked Ellison to take over the prosecution, which until Sunday had been led by the Hennepin County Attorney's Office. Freeman stood next to Ellison as the attorney general announced the charges Wednesday, but he did not speak and left midway through the news conference.

Despite the quick pace of adding charges to the investigation, Ellison sought to manage expectations, cautioning that the cases could take "months" to see through. He also brushed off the idea that intense public pressure influenced the process.

The charges noted that Floyd was "calm" after he was first arrested and before Chauvin knelt on his neck. The complaint also noted three times that after Floyd was pinned to the pavement by three officers, none of them moved from their positions despite pleas from Floyd. Video of the incident showed that bystanders also pleaded with police.

Floyd had told the first two officers at the scene — Lane and Kueng — that he was not resisting arrest but did not want to get into the back of their squad car because he is claustrophobic, the charges said.

Walz issued a statement after Ellison announced the new charges. "I laid flowers at George Floyd's memorial this morning. As a former high school history teacher, I looked up at the mural of George's face painted above and I reflected on what his death will mean for future generations. What will our young people learn about this moment? Will his death be just another blip in a textbook? Or will it go down in history as when our country turned toward justice and change?

"It's on each of us to determine that answer," Walz said. "The charges announced by Attorney General Keith Ellison today are a meaningful step toward justice for George Floyd. But we must also recognize that the anguish driving protests around the world is about more than one tragic incident.

"George Floyd's death is the symptom of a disease. We will not wake up one day and have the disease of systemic racism cured for us. This is on each of us to solve together, and we have hard work ahead," he said. "We owe that much to George Floyd, and we owe that much to each other."

One of the attorneys representing Floyd's family, Benjamin Crump, released a statement Wednesday praising the arrest and charging of the other three officers and the upgrading of murder charges against Chauvin. Crump's statement came after the Star Tribune first reported the charges and before Ellison's office made any official announcements.

"This is a bittersweet moment for the family of George Floyd," said the joint statement by Floyd's family, Crump and the legal team. "We are deeply gratified that Attorney General Keith Ellison took decisive action in this case, arresting and charging all the officers involved in George Floyd's death and upgrading the charge against Derek Chauvin to felony second-degree murder."

Minneapolis Mayor Jacob Frey also released a statement in support of the new charges.

"That George Floyd's plea — that his struggle to survive — went unrecognized and unaided by not just one but four officers will live forever as the most chilling moments in our city's history," Frey said. "Failing to act amounted to a failure to recognize George's humanity."

Attorney Eric Nelson, who is representing Chauvin, declined to comment. Chauvin remains in custody at the state prison in Oak Park Heights.

Kueng's attorney, Thomas Plunkett, released a statement Wednesday stating that his client was asked at 1:20 p.m. to turn himself in; he is being held at the Hennepin County jail. Plunkett, who represented former Minneapolis officer Mohamed Noor when he was tried and convicted in 2019 for fatally shooting Justine Ruszczyk Damond, declined further comment.

Attorney Earl Gray, who is representing Lane, also declined to comment. Gray represented Yanez when he was tried and acquitted in 2017 for fatally shooting Castile.

Thao's attorney, Robert Paule, could not be reached for comment.

Floyd's family and Crump, their lawyer, called the new charges "a significant step forward on the road to justice, and we are gratified that this important action was brought before George Floyd's body was laid to rest … That is a source of peace for George's family in this painful time."

They urged Ellison to continue the investigation and upgrade the charges to first-degree murder, which carries a potential life sentence.

First-degree murder requires proof of planning out the crime. Second-degree unintentional murder carries a maximum sentence of 40 years. Murder in the third degree has a maximum 25-year sentence. Charges of aiding and abetting carry the same maximum penalties as the underlying crime.

"These officers knew they could act with impunity, given the Minneapolis Police Department's widespread and prolonged pattern and practice of violating people's constitutional rights," the family's statement said. "Therefore, we also demand permanent transparent police accountability at all levels and at all times."

The family thanked the "outpouring" of support it has received, which manifested in days of huge protests across the country and world.

"Our message to them: Find constructive and positive ways to keep the focus and pressure on," they said. "Don't let up on your demand for change."

The former officers' prosecution is the quickest in Minnesota history against officers on the job who have killed civilians, and is the first time more than one officer involved in such an incident has been criminally charged. Three officers have previously been charged with killing a civilian on the job; Noor was convicted at trial while two were acquitted.

"Let me be honest here, our country has under-prosecuted these matters in Minnesota and throughout the country," Ellison said. "We can't control the past. All we can do is take the case that is in front of us right now and do our good-faith best to bring justice to this situation, and we will."