Citing "an extremely serious threat to public health," prosecutors in the case of four fired Minneapolis police officers charged in the death of George Floyd have asked the judge to reconsider his decision to try Derek Chauvin in March and the other three officers five months later.

The motion filed Tuesday afternoon comes less than a week after Judge Peter Cahill's order splitting the trial into two. As of now, Chauvin will be tried in Hennepin County District Court starting March 8; J. Alexander Kueng, Thomas Lane and Tou Thao will be tried together starting Aug. 23.

The judge wrote then that COVID-19, social distancing protocol and uncertainty about the vaccine rollout prevented the four defendants from being tried in one trial.

In Tuesday's motion, Assistant Attorney General Matthew Frank cited the arrival of a new, more infectious strain of COVID-19 to Minnesota, and asked that the four be tried jointly this summer, when vaccines are more widely available.

"Although the State continues to stand ready to try this case on March 8, the State believes that the timing of this trial is enormously consequential for public health," the motion reads. "The difference between following the Court's current schedule — one trial in March, and one in August — and holding a single joint trial in the summer of 2021 may well be a matter of life and death for some Minnesotans."

The motion includes an affidavit by epidemiologist Michael Osterholm, director of the Center for Infectious Disease Research and Policy at the University of Minnesota. Osterholm wrote that he anticipates the COVID-19 vaccine to be available to the general population by late spring.

He anticipates there being 5,000 to 8,000 new cases in Minnesota per day of the new coronavirus strain by March, and warned that Chauvin's trial, if held then, could become a superspreader event.

"It could be extremely dangerous to hold a trial for Mr. Chauvin in March 2021. Doing so could have potentially catastrophic consequences for public health," Osterholm wrote. "This is so not simply because of the [relatively small] number of people who would be inside the courtroom, but also because of the large numbers of people likely to be convened outside the courthouse, including demonstrators."

Two trials rather than one in connection with Floyd's death on May 25, he added, would only exacerbate that risk.

Cahill's decision to try Chauvin separately came after the four defense attorneys consulted with Hennepin County Chief Judge Toddrick Barnette and expressed their intentions to each have a second attorney or a legal aide at their table during trial.

Barnette e-mailed Cahill last Friday urging him to split up the trial because of COVID concerns, noting that the courtroom could accommodate three defendants at most.

Attorney General Keith Ellison, whose office is leading the prosecution with assistance from the Hennepin County Attorney's Office, maintained that all four defendants should be tried together to avoid retraumatizing witnesses and family members, and to limit prejudicing potential jurors between trials.

His office previously requested one trial, and filed a motion last month asking Cahill to delay proceedings until June 7, when more people would be vaccinated against COVID-19.

Chauvin's attorney, Eric Nelson, and Thao's attorneys, Robert and Natalie Paule, also filed separate motions last month asking to delay the trial to an unspecified date and to July 5, respectively, in order to deal with copious evidence.

Star Tribune staff writer Chao Xiong contributed to this report.

Abby Simons • 612-673-4921