In an unusual legal maneuver, Minnesota Attorney General Keith Ellison will take the lead in the prosecution of the fired Minneapolis police officer charged with killing George Floyd, an unarmed black man who died last week in police custody.

Gov. Tim Walz said Sunday that he concluded Ellison needed to take over the case from the Hennepin County Attorney's Office at the urging of Floyd's family, community activists, and some members of the Minneapolis City Council seeking a vigorous prosecution of the officer, 44-year-old Derek Chauvin.

"This decision is one that I feel takes us in that direction and the step to start getting the justice for George Floyd," Walz said Sunday. "When I spoke to the Floyd family they were very clear: They wanted the system to work for them. They wanted to believe that there was trust and they wanted to feel like the facts would be heard and justice would be served."

Ellison said he plans to "bring to bear all the resources necessary" to prosecute the case. "I just want to let the public know we are pursuing justice, we are pursuing truth, we are doing it vigorously," Ellison said.

Earlier Sunday, Hennepin County Attorney Mike Freeman said that he asked for Ellison's help and that the state attorney general agreed to be a full partner in the proceedings.

"There have been recent developments in the facts of the case where the help and expertise of the Attorney General would be valuable," Freeman said in a statement.

Freeman faced intense pressure to bring charges quickly against Chauvin, and Ellison told reporters that he expects the two of them will work constructively together. "The governor has asked me to take this case and that's what we're going to do," he said. "I anticipate we're going to be working constructively together."

Chauvin was charged with third-degree murder and second-degree manslaughter in connection with Floyd's death, which followed his arrest on Memorial Day for allegedly passing a counterfeit $20 bill. Video of the arrest showed Chauvin holding his knee for several minutes on Floyd's neck as he lay cuffed on the street near the intersection of S. Chicago Avenue and 38th Street.

Chauvin also stands accused of ignoring another officer who expressed concerns about Floyd as he lay on the ground, pleading that he could not breathe as onlookers begged the officers to let him up.

Chauvin was fired along with three other officers who were at the scene. He was arrested Friday and initially held in the Ramsey County jail. Corrections Commissioner Paul Schnell said Sunday that he was transferred to the state prison at Oak Park Heights, rather than the Hennepin County jail, which was anticipating an influx of arrests related to the weekend's protests. He is scheduled to make his first court appearance June 8 in Hennepin County Court.

So far, Chauvin is the only officer to face criminal charges in Floyd's death. He is the first white officer in Minnesota to be criminally prosecuted in the death of a black civilian. The maximum sentence for third-degree murder is 25 years; the maximum for second-degree manslaughter is 10 years.

Ellison said Friday that he had "every expectation" authorities would press charges against all four officers involved in Floyd's arrest. But after officially taking over the Floyd case Sunday, he said he could not talk about possibility of other charges.

"It's just too early to discuss that," he said.

The other three officers have been identified as Thomas Lane, Tou Thao and J. Alexander Kueng. While they remain free, all four officers are under investigation by state prosecutors and the U.S. Attorney's Office and the FBI, which is determining whether Floyd's constitutional rights were violated.

The charges against Chauvin have not quelled protests that are entering their second week, drawing tens of thousands of demonstrators, many of them angry that he is not facing more serious murder charges or that the other three officers have not been charged.

Ellison said it is not unprecedented for his office's criminal division to take over cases for county attorneys' offices, but the practice is more common in smaller counties. The move also came just two days after Freeman highlighted his office's experience trying officers, in particular its success in securing the conviction of Mohamed Noor, a Minneapolis police officer found guilty in the 2017 shooting death of a woman in south Minneapolis who had called 911 for help.

Stephen Montemayor • 651-925-5048