Testimony from pulmonologist Martin Tobin dominated the ninth day of former Minneapolis police officer Derek Chauvin’s trial when the doctor commented on jurors on George Floyd’s ability to breathe while in restraint.
During his time at the booth, Tobin denied the influence that fentanyl had on Floyd’s breathing just before he lost consciousness, and pushed back against claims that pre-existing health conditions caused his death.
The defense has argued throughout the trial that both Floyd’s drug use and underlying health conditions played a role in his death, while prosecutors have claimed that Chauvin̵
Tobin testified that Floyd died of a low oxygen content, which he said caused brain damage and led to a reaction that caused his heart to stop.
Chauvin’s knee placed on the man’s neck was among a “series of forces” that Tobin said contributed to Floyd’s death.
According to pool reports, jurors were very attentive to the doctor through the hour-long testimony and were seen taking notes and listening closely to the expert while he spoke.
The trial on Thursday also included testimony from a forensic toxicologist who reviewed Floyd’s blood and urine, as well as an emergency physician who specializes in forensic medicine.
The testimonies 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 attempt to breathe before loss of consciousness
Tobin offered a detailed account of Floyd’s breathing during the arrest and noted body movements he made during Chauvin, which the doctor said was an attempt to breathe.
Tobin noticed how a photo of the arrest showed Floyd appearing to be pushing his bones and fingers to the ground and covered in a nearby police car as he was pinned to the street.
“For most people, this does not look very important. But for a physiologist, this is extraordinarily important, ”Tobin said.
“This tells you that he has used his resources and that he is now literally trying to breathe with his fingers and bones,” the doctor testified. “It’s a very bad breath. But that is what you have to do when everything else fails, ”he said.
Tobin also testified that in another photo taken from the arrest, it appeared that Chauvin had half of his body weight on Floyd’s neck while holding back. In the photo, the tip of Chauvin’s foot could also be seen slightly from the ground as he knelt on Floyd, who was still attached to the street.
Tobin estimated that the action put 91.5 pounds “directly down” on Floyd’s neck. “Everything is aimed down at his knees,” he said.
While Tobin during cross-examination said he did not personally weigh Chauvin or his equipment to arrive at the estimate, the doctor said he “took the measurements reported.”
He also addressed the role that fentanyl played in Floyd’s breathing during the arrest.
“If fentanyl has an effect and causes depression in respiratory centers, the centers that control breathing, it will result in a decrease in respiratory rate, and it has been shown that with fentanyl, you expect a 40 percent reduction in respiratory rate,” Tobin said.
“So with fentanyl, his respiratory rate should be down to around 10, instead it is right in the middle of normal at 22,” Tobin said, adding that the evidence proves “there is no fentanyl on board affecting his respiratory centers. ”
Prosecutors also tried to remove claims, as Floyd said, “I can’t breathe,” during his arrest proved he could still breathe because he could talk.
Tobin said such allegations are “misleading” and offer a “huge 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 on Thursday, Chauvin defense attorney Eric Nelson questioned Tobin’s calculations from his testimony with prosecution.
“Now with regard to the calculations you have made. Do you agree that your calculations are generally theoretical, correct?” Asked Nelson Tobin.
“No, they are not theoretical. I mean, they are based on direct measurements. They are based on extensive research,” Tobin said.
Drug levels in Floyd’s body after death
Floyd’s drug use remained a focal point in the second witness’ testimony 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 about it suboxone, a prescription drug that has been 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 and tried to help each other overcome the addiction.
Prosecutors and the defense questioned Isenschmid about the amounts of fentanyl and methamphetamine found in Floyd’s system on Thursday.
Isenschmid said Floyd’s body contained an amount of methamphetamine that was “consistent [a] prescription dose. ”
“Would it be considered a low level of methamphetamine?” asked a prosecutor Isenschmid.
“Yes, very low,” he replied.
Isenschmid also provided additional evidence of fentanyl detected in Floyd’s blood while discussing the relationship between the drug and norfentanyl found in his system.
“So when the body gradually removes fentanyl, it breaks it down from fentanyl to norfentanyl,” Isenschmid said. “It is a gradual process that takes place over time. And it’s one of the ways in which the body eliminates fentanyl. ”
“And you suggested that the amount of norfentanyl found in the hospital’s blood in this case was 5.6 nanograms per milliliter … what’s significant about that amount of norfentanyl?” asked a prosecutor.
Isenschmid said it shows “that some of the fentanyl was metabolized to norfentanyl.”
Isenschmid said that more often in cases of death involving fentanyl, “we often see fentanyl without norfentanyl at all, because after a very acute fentanyl poisoning, the body does not have time to break it down.”
The testimony may be useful for prosecution as it seems to remove arguments from the defense that drug use played a role in Floyd’s death.
Witnesses addressed Floyd’s underlying health issues
At one point in his testimony, Tobin suggested that Floyd’s pre-existing health conditions did not affect his death, adding that a “healthy person” would have died under similar conditions.
When prosecutor Jerry Blackwell was asked if he was aware that Floyd had pre-existing health conditions, Tobin replied “yes, it’s me.” He stated that he read about them in records from Hennepin County and saw them mentioned in the autopsy report.
“Do you have an opinion in a reasonable degree of medical certainty as to whether a person who did not have any of the pre-existing health conditions, a healthy person, would have died of the same circumstances as Mr. Floyd?” Asked Blackwell.
“Yes, a healthy person who was exposed to what Mr. Floyd was exposed, would have died as a result of what he was exposed to, “Tobin replied.
Blackwell visited the subject later in the testimony and asked if “any of these matters have anything to do with the cause of Mr. Floyd’s death in your professional opinion, at all?”
“No one, at all,” Tobin replied.
“And again, what was the reason such that these conditions do not matter?” Asked Blackwell.
“The cause of death is a low oxygen content that caused brain damage and caused the heart to stop,” Tobin replied.
During cross-examination of Tobin, Nelson suggested that Floyd’s pre-existing health conditions contributed to his death.
Nelson noted that Floyd had “a heart disease” and “between 75 and 90 percent occlusion of his ventricular arteries.”
“And it will affect a person’s blood flow, right? It will make the body work a little harder to get the blood through the body, ”Nelson Tobin asked.
“No, not really, it will not,” Tobin replied.
When asked how it would affect a person’s respiratory system, Tobin laid out two scenarios before concluding “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 Chauvins knees were on Floyd’s neck the moment his body’s oxygen level reached zero, adding that the knee remained there for more than three minutes afterwards.
Blackwell presented a graphic that illustrated the moment Floyd’s oxygen level reached zero.
When asked to explain to the jury what the exhibition illustrated, Tobin said “We see that the oxygen level has dropped to zero, that there is at that time not an ounce of 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 where there is not an ounce of oxygen left in the body,” Tobin Blackwell said.
During his testimony, Tobin also went through the jury through slower spectators who were taken at the scene of Floyd’s arrest, who he says captured “the moment the light goes out” of Floyd’s body. At that point, Chauvin’s knee remained on Floyd’s neck.
“In the beginning you can see that he is conscious. You can see slightly flickering. 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 can see that he is not. That is the moment life goes out of his body, ”he said when the footage showed that Floyd’s face was pressed to the ground.
Bill Smock, an emergency physician who specializes in forensic medicine, also discussed Floyd’s cause of death during his testimony. When asked by Blackwell what he thought was Floyd’s cause of death, he said he died of “position swallowing”.
“Mr. Floyd died of suffocation, which is a fancy way of saying he died because he had no oxygen left in his body,” Smock said.
“So what have we referred to as low oxygen content?” Asked Blackwell.
“Low oxygen content is one way, no oxygen. When the body is deprived of oxygen, in this case from pressure on the chest and back, he gradually succumbed to lower and lower oxygen levels until it was gone and he died, ”Smock added.
Later in the testimony, Blackwell asked if Floyd died of anything other than postural ingestion, including a heart attack, blood clots in his arteries, and an arrhythmia that would cause a sudden death.
“There was absolutely no evidence of an autopsy of anything that suggested that Mr. Floyd had a heart attack, ”Smock said.
“There is no evidence of blood clots in any of the arteries, 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 agitated delirium as a factor in Floyd’s death. Smock described this condition as “a physical and psychiatric condition in which a patient exhibits multiple symptoms due to imbalance in the brain,” 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 released by Brookings Institution last year, the controversial term was used disproportionately in cases involving black people and police meetings.