On Thursday morning, a world-reknowned pulmonologist and critical care expert left no doubt about the cause of George Floyd’s death. In stunning testimony, Dr. Martin Tobin walked the jury through the exact second Floyd died, stating “That’s the moment the life goes out of his body.”
Tobin was asked by the prosecution if he had “formed an opinion to a reasonable degree of medical certainty?” He responded, “Yes, I have.” Tobin declared, “Mr. Floyd died from a low level of oxygen, and this caused damage to his brain that we see. And it also caused a PEA [pulseless electrical activity] arrhythmia that caused his heart to stop.”
Lack of oxygen stopped heart
Throughout the testimony, jurors received an in-depth lesson on lung function and anatomy. Tobin is a professor of Pulmonary and Critical Care Medicine at Loyola University Stritch School of Medicine. He is also a highly published researcher in clinical medicine. Tobin says he has taught respiratory care to thousands of doctors, nurses, respiratory therapists and more. He is the author of “Principles and Practice of Mechanical Ventilation” – a nearly 1600 page medical textbook called the “ventilator bible” by some.
For more than three hours, the doctor dissected each moment to explain the factors preventing Floyd from breathing properly. He walked jurors through the calculations he used to determine the weight former Minneapolis police officer Derek Chauvin was forcing onto Floyd’s neck. Tobin estimated “91.5 pounds that’s coming down directly on Mr. Floyd’s neck” between the body and gear weight.
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The court learned that, excluding the weight of the knee on Floyd’s neck, he was likely experiencing difficulty breathing at a roughly three-fold increase from normal. Floyd was held handcuffed and prone on the ground – two factors that undoubtedly led to low oxygen reaching Floyd’s brain according to Tobin.
The jurors listened as Tobin counted aloud the number of breaths Floyd took while handcuffed directly prior to his death. At this point, he shredded the defense’s claim that Floyd died due to a Fentanyl overdose. By Tobin’s calculations, Floyd’s rate of respiration (the number of breaths per minute) was 22 in the moments before he lost consciousness – a normal rate. If Floyd was dying due to a Fentanyl overdose, Tobin explained, his rate of respiration would have been less than half of that.
Despite the doctor’s calm and professional demeanor, the testimony was no doubt extremely emotional for those listening. Tobin explained in great detail how Floyd’s life was literally squeezed out of him. During the first five minutes and three seconds, according to Tobin, Floyd’s oxygen levels were high enough to keep his brain alive. And then, Tobin identified the exact moment Floyd had “not one ounce of oxygen left in his body.”
Knee stays on neck after all oxygen leaves body
He said, “He reaches a level of zero oxygen at 20:25:41. At that point, there’s not an ounce of oxygen left in his entire body.” Prosecutors followed up by asking, “Was the knee then lifted off of his neck at the point that there was no oxygen left in his body?”
“No,” Tobin said. “The knee remained on the neck for another 3 minutes and 2 seconds after we reach the point where there’s not one ounce of oxygen left in the body… After the officers have found themselves (that) there’s no pulse, the knee remains on the neck another 2 minutes and 44 seconds.”
The court recessed for lunch directly following the conclusion of the prosecution’s line of questioning. The court took a longer than usual lunch break, likely because the defense needed additional time to consult with their medical experts. When the court returned to session, the defense attorney Eric Nelson had begun the cross-examination of Tobin.