Doctors dispute Chauvin's 'drug overdose' defense

DEFENSE ATTORNEY ERC NELSON: "I'm taken by your accent..."

DR. MARTIN TOBIN: "I can't compensate for it."

A critical care doctor with an Irish brogue commanded the jury's attention on Day 9 of the murder trial of Derek Chauvin.

The prosecution's witness testified that George Floyd died from a lack of oxygen caused by being handcuffed face down in the street with the former Minneapolis police officer's knee on his neck.

TOBIN: "Mr. Floyd died from a low level of oxygen."

The testimony from Dr. Martin Tobin, a pulmonary expert who treats patients in a Chicago ICU, came equipped with charts, anatomical diagrams and mathematical formulas to confirm the county medical examiner's finding that Floyd's death was a homicide at the hands of police.

TOBIN: "We're seeing that the level of oxygen has gone down to zero. That there is, at that point, there's not an ounce of oxygen left in his body. And, again, this is totally... you can figure this out with very precise science."

At one point, Dr. Tobin unbuttoned his shirt collar and had jurors feeling the backs of their necks as he described how Chauvin's knee compressed Floyd's airway.

TOBIN: "...and you put your whole palm of your hand around it... Sorry?"

The judge interrupted to tell the jury they didn't have to follow his instructions.

JUDGE PETER CAHILL: "You are not required to do anything that the witness instructs you to do. But feel free to do it if you wish."

Almost all jurors followed along.

Crucially, Dr. Tobin also said the medical evidence contradicted the argument by Chauvin's defense that Floyd may have died from a drug overdose in the May 25th arrest, and compared the restraint Floyd was in to a vice.

TOBIN: "A healthy person subjected to what Mr. Floyd was subjected to would have died as a result of what he was subjected to."

Defense attorney Eric Nelson tried to argue that traces of fentanyl and methamphetamine found in Floyd’s system may have played a role in his limited breathing.

NELSON: "...fentanyl is a respiratory depressant."

But prosecutor Jerry Blackwell attempted to put that argument to rest.

BLACKWELL: "Did you see any depression in Mr. Floyd’s ability to breathe whatsoever before he went unconscious?"

TOBIN: "No. Absolutely not."

The prosecution then called to the stand a forensic toxicologist, who said the levels of the fentanyl and methamphetamine found in Floyd's blood were much lower than that of the average DUI case.

PROSECUTOR ERIN ELDRIDGE: "Would that be considered a low level of methamphetamine?"

DR. DANIEL ISENSCHMID: "Yes, very low."

And Thursday's final witness, a surgeon from Louisville who trains police about the dangers of using pressure on a suspect’s neck, said Floyd could not breathe because of Chauvin's knee.

DR. WILLIAM SMOCK: "That is not a fentanyl overdose. That is somebody begging to breathe."