The testimony of pulmonologist Martin Tobin dominated the ninth day of the trial of Derek Chauvin, a former Minneapolis police officer, as doctor-judges commented on George Floyd’s ability to breathe while under control.
During his time on the stand, Tobin refuted the impact fentanyl had on Floyd’s breathing, just before he lost consciousness, and pushed back against the allegations that the existing health conditions caused his death.
The defense argues through the trial that both Floyd’s drug use and underlying health conditions played a role in his death, while prosecutors allege that Chauvin’s knee placement and the use of force on his neck caused his death.
Tobin testified that Floyd died at a low oxygen level, which he said caused damage to his brain and led to a reaction that caused his heart to stop.
Chauvin’s knee placed on the man’s neck was a ‘series of forces’ that Tobin contributed to Floyd’s death.
According to the reports from the pool, jurors paid a lot of attention to the doctor during the hours-long testimony and saw them take notes and listen to the expert while he spoke.
The trial Thursday also includes testimony from a forensic toxicologist who assessed Floyd’s blood and urine, as well as an emergency medicine physician who specializes in forensic medicine.
The evidence provided more insight into the amount of drugs found in Floyd’s system after his death and further opinion from experts on how Floyd died.
Floyd’s attempts to breathe before losing consciousness
Tobin gave a detailed account of Floyd’s breathing during the arrest and noted that he made body movements under Chauvin, which according to the doctor was an attempt to breathe.
Tobin noticed a photo of the arrest showing Floyd apparently pushing his knuckles and fingers against the ground and tire of a nearby police vehicle as he was pinned to the street.
‘For most people, it does not seem very important. But for a physiologist, it is extremely important, ”Tobin said.
“It tells you that he has used up his resources and that he is now literally trying to breathe with his fingers and knuckles,” the doctor testified. ‘It’s a very bad way to breathe. But that is what you have to do if everything else fails, ”he said.
Tobin also testified that it appears that in another photo of the arrest, Chauvin had half of his body weight on Floyd’s neck while holding him in check. In the photo, the tip of Chauvin’s foot was also slightly off the ground when he knelt on Floyd, who was still pinned to the street.
Tobin estimates that the action put 91.5 pounds ‘directly off’ on Floyd’s neck. “Everything is on his knees,” he said.
While Tobin said during cross-examination that he did not personally weigh Chauvin or his equipment to arrive at the estimate, the doctor said he “took the measurements that are reported.”
He also addressed the role that fentanyl had on Floyd’s breathing during the arrest.
‘If fentanyl has an effect and causes depression in the respiratory centers, the centers that control respiration will result in a decrease in the respiratory rate, and it is shown that with fentanyl you expect a 40 percent decrease in the respiratory rate. , ”Tobin said.
“So, with fentanyl, his breathing rate should be around 10, instead it is at 22 in the middle of normal,” Tobin said, adding that the evidence proves that “there is no fentanyl on board that has the effect. . his breathing centers. ”
The prosecutor also wanted to allege that during his arrest, Floyd said, “I can’t breathe,” that he could still breathe because he could talk.
Tobin said such allegations were “misleading” and offered an “enormous false sense of security.”
“The moment you speak, you are definitely breathing. “But it does not tell you that you will breathe five seconds later,” he said.
During cross-examination later Thursday, Chauvin’s defense attorney Eric Nelson questioned Tobin’s calculations from his testimony with prosecution.
“Now in terms of the calculations you made. You would agree that your calculations are generally theoretical, correct?” Nelson asks Tobin.
“No, they are not theoretical. I mean it is based on direct measurements. They are based on extensive research,” Tobin said.
Drugs in Floyd’s body after death
Floyd’s drug use remained a focal point in the testimony of the second witness Thursday, coming from Daniel Isenschmid, a forensic toxicologist who analyzed Floyd’s blood and urine.
Isenschmid said in his testimony that fentanyl and methamphetamine were found in Floyd’s blood, while morphine was detected in his urine. He also testified suboxon, a prescription drug used to treat opioid addiction, was found in his blood.
Floyd’s ex-girlfriend, Courteney Ross, testified during the trial last week that she and Floyd both struggled with opioid abuse, trying to help each other overcome the addiction.
The prosecution and defense questioned Isenschmid about the amounts of fentanyl and methamphetamine found in Floyd’s system on Thursday.
Isenschmid said Floyd’s body contains an amount of methamphetamine that “corresponds to [a] prescription dose. ”
“Would that be considered a low level of methamphetamine?” asked a prosecutor Isenschmid.
“Yes, very low,” he replied.
Isenschmid also gave further evidence about the fentanyl detected in Floyd’s blood, while discussing the relationship between the drug and norfentanyl in his system.
“So when the body gradually eliminates fentanyl, it breaks it down from fentanyl to norfentanyl,” Isenschmid said. ‘It’s a gradual process that takes place over time. And this is one of the ways in which the body eliminates fentanyl. ”
“And you indicated that the amount of norfentanyl in the hospital blood in this case was 5.6 nanograms per milliliter … what is significant about the amount of norfentanyl?” asks a prosecutor.
Isenschmid said it shows “that some of the fentanyl has been metabolized to norfentanyl.”
Isenschmid said it is more common in cases of fentanyl deaths that “we see fentanyl regularly without any norfentanyl, because after a very acute fentanyl poisoning the body does not have time to break it down.”
The evidence could be useful for prosecution, as it helps dispel arguments from the defense that drug use played a role in Floyd’s death.
Witnesses Address Floyd’s Underlying Health Issues
Tobin suggested at one point in his testimony that Floyd’s existing health conditions did not affect his death, adding that a ‘healthy person’ would have died under similar conditions.
When asked by prosecutor Jerry Blackwell if he was aware that Floyd already had pre-existing health conditions, Tobin replied “yes, I am.” He stated that he had read about it in Hennepin County records and saw how they were mentioned in the autopsy report.
‘Do you believe in a reasonable degree of medical certainty whether someone who did not have any of the existing health conditions, a healthy person, would have died of the same circumstances as Mr. Floyd? ‘ Ask Blackwell.
“Yes, a healthy person who is subject to what Mr. Floyd is subject to would have died as a result of what he has been subject to,” Tobin replies.
Blackwell revisited the subject later in the testimony and asked whether ‘any of these conditions in your professional opinion have anything to do with the cause of Mr. Floyd? ‘
“None, at all,” Tobin replied.
“And what was the cause again, such that those conditions did not matter?” Ask Blackwell.
“The cause of death is a low level of oxygen that caused the brain damage and caused the heart to stop,” Tobin replied.
During Tobin’s cross-examination, Nelson suggested that Floyd’s pre-existing health conditions contribute to his death.
Nelson noted that Floyd “had some form of heart disease” and “had between 75 and 90 percent occlusion of his ventricular arteries.”
‘And it’s going to affect a person’s blood flow, right? ‘It’s going to make the body work a little harder to get the blood through the body,’ Nelson asked Tobin.
“No, not really, it’s not going to do,” Tobin replied.
Asked how it would affect the person’s respiratory system, Tobin explained two scenarios before concluding that “we do not see either.”
Experts testify that Floyd died while Chauvin’s knee was on his neck
At another point in his testimony, Tobin said that Chauvin’s knee was on Floyd’s neck the moment his body’s oxygen level reached zero, adding that the knee then remained there longer than three minutes.
Blackwell presented a graphical representation of the moment Floyd’s oxygen level reached zero.
When asked to explain to the jury what the exhibition illustrates, Tobin said: “We see that the oxygen level has dropped to zero, that at that point there is no oxygen left in his body.”
Blackwell then asked how long Chauvin’s knee remained on Floyd’s neck after his oxygen was depleted.
“The knee remained on the neck for another three minutes and two seconds after we reached the point that there was not one gram of oxygen left in the body,” Tobin told Blackwell.
During his testimony, Tobin also walked through the jury through delayed bystander material taken at the scene of Floyd’s arrest, which he said was captured “at the moment the light goes out” from Floyd’s body. At that point, Chauvin’s knee remained on Floyd’s neck.
“At the beginning you can see he is conscious. You can see flickering slightly. And then it disappears, ”Tobin said.
‘So, one second he lives and one second he is no more. … You can see his eyes, he is conscious and then you see that he is not. This is the moment that life passes from his body, ” he said as the footage showed Floyd’s face being pressed to the ground.
Bill Smock, a physician in emergency medicine who specializes in forensic medicine, also discussed Floyd’s cause of death during his testimony. When asked by Blackwell what he believes is the cause of Floyd’s death, he said he died of ‘positional suffocation’.
“Mr. Floyd died of asphyxia, which is a wonderful way to say he died because he had no oxygen in his body,” Smock said.
“What then did we call oxygen-poor?” Ask Blackwell.
‘Oxygen is low. When the body was deprived of oxygen, in this case, due to the pressure on his chest and back, he gradually gave in to lower and lower levels of oxygen until it was gone, and he died, ‘Smock added.
Later in the testimony, Blackwell asked if Floyd had died of anything other than positional suffocation, including a heart attack, blood clots in his veins, and an arrhythmia, which would have caused a sudden death.
“There is absolutely no evidence at the autopsy to indicate that Mr Floyd had a heart attack,” Smock said.
“There is no evidence of blood clots in any of the veins, there is no evidence of bleeding from a ruptured plaque, and there is no evidence that Mr. Floyd had a heart attack,” Smock said.
Smock also ruled out excited delirium as a factor in Floyd’s death. Smock described this condition as “a physical and psychiatric condition, because of an imbalance in the brain, a patient will show multiple symptoms”, including increased heart rate and respiration, and a ‘superhuman strength’.
Smock said Floyd did not show the ten signs of the condition.
According to a report by the Brookings Institution last year, the controversial term was used excessively in cases involving black people and meetings with law enforcement.