George Floyd news – live: Second expert says George Floyd died because he couldn’t breathe

George Floyd died because he couldn’t get enough air to breathe, a second expert witness testified in the Derek Chauvin murder trial on Thursday.

“Mr Floyd died of positional asphyxia, which is a fancy way of saying he died because he had no oxygen in his body,” said Dr Bill smock, a forensic medical specialist and police training doctor called to testify by the state. “When the body is deprived of oxygen, in this case from pressure on his chest and back, he gradually succumbed  to lower and lower levels of oxygen until it was gone and he died.”

Earlier in the day, Dr Martin Tobin, a lung specialist, reached a similar conclusion on the stand.

Next up on the witness stand is Dr. Bill Smock, a forensic medical specialist, the latest expert witness called up by the state.

Even though there were opioids in George Floyd’s body at the time of his death, that doesn’t mean he overdosed, Dr. Daniel Isenschmid, a forensic toxicologist who analyzed the evidence, testified on Thursday.

The defence has argued an OD caused Mr Floyd’s death, not Mr Chauvin’s knee.

Samples of blood and urine from the scene of the arrest showed Mr Floyd had both fentanyl in his body, a powerful opioid, and norfentanyl, the chemical product that results from the body breaking it down. In swift overdose cases, the toxicologist explained, that chemical byproduct doesn’t always appear since the body is still processing the original drug.

“After a very acute intoxication, the body doesn’t have time to break it down,” he said.

Still, Mr Isenschmid said this wasn’t conclusive in any direction. George Floyd could’ve had the norfentanyl in his body from a previous occasion, then taken more fentanyl on top of that.

Speaking of drugs, here’s what lung expert Dr Martin Tobin said about whether fentanyl killed George Floyd.

After much toxicological jargon, we’ve arrived at the point.

The state is arguing, with the help of their witness Dr. Daniel Isenschmid, a forensic toxicologist, that even though evidence showed George Floyd was found to have fentanyl and meth in his body at the time of his death, it wasn’t in high amounts, compared to cases even where others stayed alive afterward.

Mr Floyd’s level of meth in his body was in the bottom 5.9 percent of people in DUI cases, Mr Isenschmid explained, and had a ratio of fentanyl in his body well below the ratio normally found in both post-mortem and DUI cases involving the drug.

A major part of the defence’s case is that Mr Floyd died from a drug overdose, rather than from the knee pressed into his neck.

So far Dr. Daniel Isenschmid has mainly confirmed what we already knew: blood and urine samples from George Floyd showed he had recently consumed methamphetamine and fentanyl at the time of his fatal arrest.

Tomorrow, the Hennepin County medical examiner is expected to testify, who will help put this evidence into context about whether these drugs were involved in causing Mr Floyd’s death.

The next witness to testify is forensic toxicologist Dr. Daniel Isenschmid of NMS Laboratory.

For the last half hour or so, defense attorney Eric Nelson has been questioning various aspects of the medical testimony from Dr Martin Tobin, the lung expert who concluded that a lack of oxygen killed George Floyd.

“You’ve had the luxury of slowing things down,” Mr Nelson said, and noted how unlike doctors, police responding to rapidly changing circumstances on the ground have “nowhere close” to the level of his medical experience.

Mr Nelson also noted George Floyd had various factors—fentanyl in his body, recent meth use, heart disease, a potential surge in adrenaline in his body—all of which could’ve complicated his health during the fatal arrest in ways that might suggest Mr Chauvin’s knee didn’t cause his death.

But Mr Tobin said none of those things were seen to affect Mr Floyd’s body during the arrest itself. Instead, the clearest explanation for his death was a lack of oxygen.

 “A healthy person subjected to what Mr Floyd was subjected to would’ve died as a result,” the lung doctor maintained, though it’s important to note Mr Tobin did not actually conduct the autopsy on Mr Floyd, so his judgements are based on clinical experience only.

Thursday’s proceedings are up and running once again with the continued testimony of Dr Martin Tobin, an ICU doctor and lung expert the state called to testify as an expert witness.

And that’s it for the morning’s testimony. The court will be back in session at 1:30pm US Central Time (7:30pm BST) after a lunch break. Stay tuned for more news and analysis of this landmark case.