Lawyers representing former Minneapolis police officer Tou Thao argued in a new court filing late Wednesday that the medical examiner who performed the autopsy on George Floyd was "coerced" by a prominent doctor in Washington, D.C., into altering its findings – and that prosecutors were aware.

The filing accuses that same doctor, who threatened to write a damaging op-ed in the Washington Post against the medical examiner, of later targeting the key medical witness called by the defense in the trial for Derek Chauvin, resulting in an investigation by the state of Maryland following his testimony. That has caused a "chilling effect," Thao's defense attorneys argue, making it difficult for the defense to find other medical experts to testify for fear of losing their licenses or damaging their reputation.

The lawyers for Thao, Thomas Lane, J. Kueng – the three officers at the scene when Chauvin pressed his knee into the neck and upper back of Floyd for more than nine minutes – appeared in court Thursday to argue pre-trial motions. Judge Peter Cahill pushed the trial for the three officers back to March 2022 and also weighed a request that prosecutors be sanctioned or submit written affidavits stating that they were not responsible for leaking to the media that Chauvin had agreed to plead guilty to a third-degree murder charge last year before then-Attorney General William Barr refused.

In the filing on behalf of Thao, his attorneys, Robert and Natalie Paule, argued that Dr. Andrew Baker, the Hennepin County Medical Examiner, was "directly and indirectly coerced by the State and its agents." Baker performed an autopsy on Floyd on May 25, 2020, and told prosecutors the next day that he found "no physical evidence suggesting that Mr. Floyd died of asphyxiation," the attorneys wrote.

GEORGE FLOYD DEATH: CHAUVIN COULD FACE TOUGHER SENTENCE AS MINNESOTA JUDGE FINDS AGGRAVATING FACTORS 

The filing notes two subsequent phone conversations between Baker and Dr. Roger Mitchell, the former medical examiner of Washington, D.C. Before Baker finalized his findings on June 1, Mitchell read the preliminary report and called Baker to tell him he should "first of all fire his public information officer" and ask what happened because "Mitchell didn't think it sounded like Baker's words."

During the call, "Baker said that he didn't think the neck compression played a part," the filing said.

Mitchell called Baker back a second time to tell him he planned to submit a piece to the Washington Post criticizing his finding. During the conversation, "Mitchell said neck compression has to be in the diagnosis," according to Thao's defense attorneys.

Mitchell, now chairman of the Department of Pathology at the Howard University College of Medicine, also allegedly told Baker, "You don't want to be the medical examiner who tells everyone they didn't see what they saw. You don't want to be the smartest person in the room and be wrong."

The final autopsy findings included neck compression – contrary to Baker's conclusion before speaking with Mitchell twice, according to the filing.

"Dr. Mitchell orally made the threat to unlawfully injure Dr. Baker's trade unless Dr. Baker changed his autopsy findings," the filing alleges. "Dr. Mitchell told Dr. Baker to include neck compression in the final findings and warned Dr. Baker he was going to publish a damaging op-ed in the Washington Post. After Dr. Baker changed his findings, Dr. Mitchell did not publish the op-ed."

Thao’s defense team also cited a letter penned by Mitchell after Dr. David Fowler, who was Maryland's chief medical examiner from 2002 to 2019 and is now a member of a consulting firm, testified during the trial for Chauvin that his medical opinion was that the cause of Floyd's death was "undetermined."

Fowler testified that the primary cause of Floyd's death was a sudden heart rhythm disturbance during police restraint due to underlying heart disease. Just eight days later, Mitchell penned a letter to Maryland Attorney General Brian Frosh, director of the Department of Health for the State of Maryland Allison W. Taylor, U.S. Attorney General Merrick Garland, and CDC director Rochelle Walensky.

The letter, signed by 431 doctors from around the country, called for immediate investigations at the state and federal level into Fowler's medical license as well as a review into the Maryland Office of the Chief Medical Examiner during Fowler's 17-year tenure.

MARYLAND TO INVESTIGATE DEREK CHAUVIN DEFENSE WITNESS' TENURE AS STATE'S CHIEF MEDICAL EXAMINER

A week after Chauvin was convicted of second-degree unintentional murder, third-degree murder and manslaughter in Floyd’s death, Maryland officials announced a review of all in-custody death reports produced by the Office of the Chief Medical Examiner while under Fowler’s leadership.

"Dr. Mitchell unlawfully injured Dr. Fowler’s trade by penning an open letter, which resulted in an investigation into every death report in Maryland during Dr. Fowler’s tenure," the filing by Thao’s defense attorneys reads. "Dr. Mitchell has set the stage that he will threaten the trade and professional reputation of any physician who suggests that Mr. Floyd’s death could be labeled as ‘undetermined’." 

Mitchell "has essentially stated that any medical expert who wants to testify that Mr. Floyd’s death could be undetermined should, and will, face penalties by him," it continues. "Dr. Mitchell's accusations and spurring of legal fallacies creates a chilling effect for Mr. Thao and violates his due process rights in that it has become extraordinarily difficult to find medical experts who are willing to state that Mr. Floyd's death was undetermined in fear of their professional reputation and licensure."

Lane, Kueng and Thao are charged with aiding and abetting second-degree murder and aiding and abetting second-degree manslaughter. All three waived their right to appear at Thursday's hearing.

Chauvin and the other three former officers also face federal civil rights charges in Floyd's death.

In their filing Wednesday, Thao's defense teamed asked the judge to dismiss the case against their client. They also asked that Minnesota Attorney General Keith Ellison, as well as prosecutors Neal Katyal, Lola Velazquez-Aguilu, Joshua Larson, Matthew Frank, Erin Eldridge and Corey Gorden be barred from participating in any trial for Thao and that potential jurors be dismissed by the court if they acknowledge that they saw, read or have knowledge of the open letter or op-ed written by Dr. Mitchell.

Thao’s attorney, Robert Paule, previously said in a court filing in February that he wants an order sanctioning the state for "its role – directly or indirectly – in the leaking of highly prejudicial information related to potential plea agreements of co-defendants."

CLICK HERE TO GET THE FOX NEWS APP

The New York Times reported Feb. 10 that Chauvin was ready to plead guilty to a third-degree murder charge last year but Attorney General Barr rejected the agreement. The Associated Press published a similar report the next day, citing two law enforcement officials with direct knowledge of the talks. Paule alleged that the leaks came from the state, and asked that anyone who did so be barred from participating in the trial. Tom Plunkett, Kueng's attorney, echoed his statements.

Ellison earlier dismissed Paule's motion as "completely false and an outlandish attempt to disparage the prosecution."

The Associated Press contributed to this report.