Chauvin defense’s medical expert testifies carbon monoxide poisoning could have contributed to Floyd’s death

A former chief medical examiner brought in by the defense as an expert witness during the murder trial of former Minneapolis police officer Derek Chauvin on Wednesday speculated carbon monoxide poisoning could have contributed to George Floyd’s death. 

The factor was one of several David Fowler, a former Maryland chief medical examiner who was the first witness the defense called to the stand early Wednesday, listed that could have played a role in Floyd’s death. 

Fowler made the speculation while testifying about the possible exposure Floyd could have received from exhaust from a nearby squad car when he was pinned to the ground under law enforcement restraint during the arrest that preceded his death last May.

Fowler, who said he reviewed all of the footage of the arrest presented in the case, said the videos showed that Floyd’s “face was facing towards the vehicle, towards the rear of the vehicle and directly towards the area where you would expect the tailpipe or tailpipes of a vehicle to be.”

“There is exposure to a vehicle exhaust, so potentially carbon monoxide poisoning or at least an effect from increased carbon monoxide in his bloodstream,” he testified.

“And let me just ask you, are you suggesting that Mr. Floyd died from carbon monoxide poisoning?” Chauvin’s defense attorney Eric Nelson asked Fowler. 

“Absolutely not, no. Not a full carbon monoxide poisoning, no,” Fowler said.

He also noted that, to his knowledge, Floyd’s blood hadn’t been tested for carbon monoxide.

“I could not find a reference to it, no,” he said when asked by Nelson.

However, Fowler, who testified earlier that he believed Floyd died after suffering “a sudden cardiac arrhythmia or cardiac arrhythmia,” revisited the topic again when pressed further by the defense about the factors that led him to his conclusion about Floyd’s death.

“In this case, can you just kind of describe the layers of factors that led you to your conclusion that this was a sudden cardiac event?” Nelson asked him later during the trial.

“We have a heart that’s vulnerable because it’s too big. It demands lots of oxygen. It has very narrow vessels. There are certain drugs that are present in your system that make it, put it at risk of any arrhythmia, methamphetamine. … We’ve got the carbon monoxide, which has the potential to rob some of that additional oxygen-carrying capacity,” Fowler stated.

According to The Washington Post, the testimony marked the first time during that trial that one of the defense’s witnesses pointed to carbon monoxide poisoning as a potential contributing factor in Floyd’s death.

In the span of 20 minutes during Fowler’s testimony following the court’s first break, the Post reported that the term “carbon monoxide” had been said by Fowler and Nelson nearly 50 times. 

The testimony comes as the defense works to refute the prosecution’s argument that Chauvin’s use of force against Floyd during the May 2020 arrest, when the officer was seen kneeling on his neck for more than eight minutes, led to his death.

The defense has instead shifted focus to Floyd’s drug use and underlying health problems as contributing factors to his death.

When it came time for cross-examination, the prosecution needled Fowler over his speculation regarding carbon monoxide.

“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?” prosecutor Jerry Blackwell said. 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.

“Correct,” Fowler said.

“Now, there’s a reason I ask about that,” Blackwell went on. “You spent quite a bit of time talking about carbon monoxide … just going right to the punchline of carbon monoxide. … You haven’t seen any data or test results that showed Mr. Floyd had a single injury from carbon monoxide?” Blackwell asked.

“That is correct because it was never sent to the laboratory — ” Fowler began to respond before Blackwell cut in to ask if that was true. Fowler said it was.

“Have you ever laid eyes — I don’t mean pictures — physically on the squad car that you were referring to?” Blackwell asked. Fowler said he had not.

Blackwell then asked Fowler if he had seen air-monitoring data that would actually give him any information about what amount of carbon monoxide, if any, would have been in Floyd’s breathing zone.

“You haven’t seen any, have you?” Blackwell asked. Fowler said in response that he had “not seen any data.”

“Are you able to tell this jury whether or not Mr. Floyd at the time that he was being subdued on May 25 was being exposed to carbon monoxide above the limit or level that was set by the EPA [Environmental Protection Agency] of nine parts per million?”

“No, no testing was done,” Fowler said.