Judge warns of mistrial in Chauvin case if prosecution witness even ‘hints’ at ‘newly discovered evidence’

The judge in the murder trial of Derek Chauvin on Thursday rejected a request by the prosecution to enter newly discovered evidence that would have contained information about George Floyd’s carbon monoxide levels during his arrest, warning of a mistrial if the results were mentioned by their rebuttal witness before the jury.

Judge Peter Cahill ruled against the admission of evidence, saying it was unfair to the defense.

Cahill said the prosecution had an opportunity earlier to provide the evidence since it knew Fowler was raising the issue of carbon monoxide. He said allowing it now would prejudice the jury.

“It’s untimely to give the notice and it prejudiced the defense by the late disclosure, even if it’s not due to bad faith but the late disclosure has prejudiced the defense, it’s not going to be allowed,” Cahill said.

Prosecutor Jerry Blackwell had told the court that the state had just received blood gas evidence from Hennepin County Medical Examiner Andrew Baker, who performed Floyd’s autopsy, that contained readings for the carbon monoxide content in his blood on the day he was arrested.

The evidence, Blackwell said, was discovered after a former chief medical examiner called by the defense as an expert witness speculated in court that Floyd could have been exposed to carbon monoxide when he was pressed to the ground under Chauvin’s knee near a squad car last May.

Though the witness, David Fowler, said he had no knowledge of whether Floyd’s blood had even been tested for carbon monoxide, he pointed to potential carbon monoxide poisoning when listing each of the factors he felt played a role in his death. 

Blackwell grilled Fowler, the defense’s sole witness who took the stand on Wednesday, over the statements during cross-examination later that day.

“You agree as an expert witness that you shouldn’t jump to conclusions? That is, you should reach fair conclusions based upon a careful considered analysis?” Blackwell asked. Fowler agreed.

“Do you agree that you shouldn’t come at this in a way that’s biased? You agree with that, don’t you? You shouldn’t cherry-pick facts? You shouldn’t try to confuse the jury?” Blackwell continued. 

Blackwell said the state had previously subpoenaed all the medical records, but it did not receive records containing the evidence in question. 

“Dr. Baker heard the testimony, had not himself ever requested this, nor had the ER physicians. They explained that when somebody is brought in, and blood gases are taken, there’s a panel of them that are taken, the ones that get generated and the records would be the ones that the ER physicians actually request,” he said.

“Nobody requested carbon monoxide readings, because they didn’t see how that was relevant,” he added. 

“Did Dr. Baker spontaneously call you to tell you that there might be something deep within the computer records that was not disclosed or did you seek him out?” Cahill later asked.

“We did not seek him out and ask anything. He had heard the testimony and thought that this record might exist because he was aware that there’s a panel of the tests that are run by the machine,” he said.

After ruling against the prosecution, Cahill warned of a mistrial if the state’s rebuttal witness, Martin Tobin, discussed the evidence when he was expected to take the stand later.

“The defense gave notice that this was going to be an issue and specifically talked about testing the sample,” Cahill said.

“Even if it’s just because Dr. Baker called the state and said, ‘We, we can actually find this’ at 8 o’clock this morning, when the defense expert is done testifying, has left the state,” he said, referring to Fowler.

“If he even hints that there are test results the jury has not heard about, it’s going to be a mistrial, pure and simple. This late disclosure is not the way we should be operating here,” the judge also said. 

However, the judge said Tobin would be allowed to add information about carbon monoxide in regards to environmental factors when he takes the stand.

“Dr. Tobin may testify as to carbon monoxide if he sticks to the environmental factors and as a pulmonologist, looking at the videos for example and seeing Mr. Floyd’s location and not knowing whether the vehicle is even on or not, which the state brought out in cross-examination,” he said.

This story was updated at 2:06 p.m.