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Derek Chauvin

Derek Chauvin trial live: Defense medical expert says George Floyd's death was due to underlying heart issues

MINNEAPOLIS – A medical expert testifying for the defense in the murder trial of former Minneapolis police officer Derek Chauvin told jurors Wednesday the manner of George Floyd's death was "undetermined," contrary to various prosecution witnesses who labeled the death a homicide.

Dr. David Fowler, former head of the medical examiner's office in Maryland, said he believes that Floyd, due to his underlying heart issues, had a "sudden cardiac arrhythmia" while being restrained and subdued by police.

Several witnesses for the prosecution previously said Floyd died from low oxygen due to law enforcement restraint. However, the chief medical examiner for Hennepin County who conducted the autopsy told jurors Floyd's heart disease was a contributing cause of his death.

"The law enforcement subdual and neck compression is just more than Mr. Floyd could take by virtue of his heart conditions," Dr. Andrew Baker said last week. 

Where the trial stands: The defense argues Floyd's hypertensive heart disease and ingestion of meth and fentanyl, together with the struggle with police, led him to suffer from heart strain and ultimately die. On Tuesday, the defense called on a former police officer and a retired Hennepin County paramedic who both testified about Floyd's drug-related arrest in 2019 in Minneapolis.

Prosecutors, meanwhile, contend Floyd died due to Chauvin's knee on his neck for more than nine minutes. Over the course of 11 days, prosecutors called 38 witnesses to the stand and played dozens of bystander, surveillance and police body cam videos.

Chauvin is charged with second-degree murder, third-degree murder and second-degree manslaughter in Floyd's death in police custody on May 25, 2020.

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Latest updates:

  • Morries Hall, a man who was in an SUV with George Floyd before the struggle with police, won't testify in Chauvin's trial, Judge Peter Cahill ruled Wednesday.
  • Earlier, Cahill denied a motion for acquittal of Chauvin that was submitted in oral arguments by lead defense attorney Eric Nelson. Such acquittal motions by the defense are normally made at the end of the state's case, are largely pro forma legal actions in criminal trials, and are rarely if ever granted by courts.
  • The defense called its first six witnesses to the stand Tuesday after the prosecution rested its case. The last witness of the day, defense use-of-force expert Barry Brodd, told jurors Chauvin was "justified" in his use of force – the first witness to suggest the restraint on Floyd was acceptable.

Defense forensic pathologist: Floyd had a 'sudden cardiac arrhythmia'

Fowler, a retired forensic pathologist and former head of the medical examiner's office in Maryland for 17 years, told jurors Wednesday that Floyd’s death was due to his existing health issues rather than asphyxia, or low oxygen.

Fowler said the plaque built up inside Floyd's arteries and his hypertensive heart disease were the direct cause of death, in his opinion, noting that Floyd had a "sudden cardiac arrhythmia" due to those heart issues while being restrained and subdued by police.

Fowler noted that that significant contributing conditions would include: Floyd's fentanyl and methamphetamine ingestion, what other experts have called an "incidental" abnormal cell growth in his pelvic area, and exposure to vehicle exhaust that may have led to carbon monoxide poisoning. That last contributory condition has not been raised by an expert before.

Fowler conceded during cross-examination by state's attorney Jerry Blackwell that while Floyd was officially pronounced dead in the hospital, he was dead “long, long before that.” He agreed that Floyd should have been given immediate medical attention when he went into cardiac arrest.

The Minneapolis police chief has testified that the officers violated its policy by not providing CPR and chest compressions when Floyd was in medical distress.

Fowler agreed with Blackwell's characterization and said he is “critical” about officers not providing medical assistance.

“Immediate medical attention for a person who has gone into cardiac arrest, may well reverse that process,” Fowler said. 

Fowler also agreed that there isn’t any physical evidence on autopsy of what caused low oxygen in a “substantial number” of cases. The finding of positional asphyxia is one determined by further investigation, and Fowler said that “the scene information becomes very important.”

There’s no reference in Floyd’s records of a blood test for carbon monoxide, Fowler said. But he noted that a police squad car's engine was running while Floyd was restrained nearby. He explained to jurors that as carbon monoxide intake goes up, a person’s oxygen-carrying capacity goes down.

People with significant heart disease are more adversely affected and die at lower levels of carbon monoxide poisoning than healthy people, he said.

When asked how he knew the car engine was running, Fowler told Blackwell that he saw water dripping from the tailpipe. He took that to mean the police squad car ignition was turned on. He admitted that he didn’t get more information or ask to verify his conclusion about the car.

Fowler also agreed with Blackwell that he did not do testing to simulate what Floyd could have been exposed to near a similar vehicle.

Fowler also repeated prior expert witness testimony that Floyd’s right coronary artery showed the greatest amount of narrowing, at 90%, which increases the risk of sudden death. 

In this image from video, Dr. David Fowler testifies as Hennepin County Judge Peter Cahill presides, Wednesday, April 14, 2021.

Physical exertion increases the body’s need for oxygen, while methamphetamine increases the heart rate, and causes arteries to narrow to the point where it slows down blood flow, Fowler said. Methamphetamine also increases the risk of arrhythmia, he said.

"There’s multiple entities all acting together and adding to each other and taking away from a different part of the ability to give oxygen into his heart,” Fowler said. “At some point, the heart exhausted its reserves of metabolic supply and went into an arrhythmia and stopped pumping blood effectively.”

Prompted by Nelson, Fowler cited a study suggesting Chauvin's knee restraint on Floyd would have transferred less than 35 pounds of weight onto his body. Fowler did not include additional police equipment like the duty belt, which adds additional weight to the calculation.

Last week, Dr. Martin Tobin, a pulmonologist who wrote the book on mechanical ventilation and testified for the prosecution, said 91.5 pounds of Chauvin's weight was pressed directly onto Floyd's neck.

He said Floyd’s airway was "nowhere close" to Chauvin’s knee. "The bottom line is moving air, in and out, and speaking and making noise is very good evidence the airway was not closed," Fowler said.

Fowler also said Chauvin wasn’t obstructing the carotid artery, which is under the jaw, but even if he was obstructing one artery, the other carotid on the other side of the neck would still be functional.

Fowler said he got his education and early experience in Cape Town, South Africa, with an expertise in pediatric pathology, but he also is a licensed physician in the U.S. As chief medical examiner in Maryland, he said he reviewed roughly 600 homicides annually.

Fowler said he is being compensated at a rate of $350 an hour. He said he was approached by Nelson to evaluate George Floyd's cause of death case but declined to take it on himself, instead working with a panel of practitioners. 

Fowler said 13 peer reviewers across multiple disciplines were involved in this case. Seven of them are forensic pathologists; the others included pulmonologists, emergency room doctors and toxicologists were among others present, Fowler said.

Jurors were more engaged and taking notes during Blackwell's cross-examination than during Fowler's initial direct questioning by Nelson.

Fowler is currently facing a federal lawsuit. While chief medical examiner in Maryland, Fowler ruled the death of Anton Black, a Black 19-year-old experiencing a mental health crisis who was killed by police in 2018, an accident, according to The Baltimore Sun. No one was charged, and Black's family filed the lawsuit in December.

Morries Hall, man in SUV with Floyd, won't testify, judge rules

Cahill on Wednesday quashed a subpoena for testimony from Morries Hall, a man who was in the car with Floyd before the fateful struggle with police.

The judge ruled that Hall had a Fifth Amendment right not to testify because answering even narrowly-tailored questions could expose Hall to criminal charges. The charges could include allegations about possession of any drugs found in the car as well as a potential third-degree murder charge if the drugs were linked to Floyd's death.

The ruling came after Hall, appearing in court for a brief hearing before the Chauvin trial resumed, said: "I'm fearful of criminal charges going forward."

In this image from video, Morries Hall speaks as Hennepin County Judge Peter Cahill discusses motions before the court Wednesday, April 14, 2021.

Defense use-of-force expert Barry Brodd: 'Derek Chauvin was justified'

After facing several prosecution witnesses who testified about police use of force in Floyd's death, the defense called Brodd, a police-use-of-force expert, to provide a counterpoint for the jury.

"I felt that Derek Chauvin was justified, acting with reasonableness," he said.

Brodd testified in 2018 in the trial of Chicago Police Officer Jason Van Dyke, charged in the shooting of 17-year-old Laquan McDonald in 2014. Brodd testified Van Dyke's use of force against Laquan McDonald was justified. Van Dyke was later found guilty of second-degree murder.

In this image from video, Barry Brodd, a use of force expert testifies as Hennepin County Judge Peter Cahill presides, Tuesday, April 13, 2021.

Brodd said the level of force the officers used when they tried to put Floyd into the back of the police patrol car  and to force Floyd onto the ground was "objectively reasonable," though he added: "I don't consider a prone control as a use of force."

During cross-examination, prosecutor Steve Schleicher's questioning enabled the prosecution to re-play, yet again, audio and video of Floyd struggling and saying he could not breathe. Brodd acknowledged that Floyd's cries "could" mean he faced a potential threat of positional asphyxia. Read more on Brodd's testimony here.

George Floyd's nephew: 'To the world, I just simply say: Damn, again?'

The family of Floyd and their attorneys stood outside the courthouse Tuesday afternoon alongside the family of Daunte Wright. Police fatally shot Wright, a 20-year-old Black man, in nearby Brooklyn Center during a traffic stop Sunday in what the police chief called an "accidental discharge."

"It is unbelievable – it is just something I cannot fathom that in Minneapolis, Minnesota, a suburb 10 miles from where the Chauvin trial regarding George Floyd was taking place, that a police officer would shoot and kill another unarmed Black man," civil rights attorney Ben Crump said.

Brandon Williams, Floyd's nephew, sent his condolences to the Wright family. "We’ve been in a similar situation," he said. "To the world, I just simply say: Damn, again? And when I say damn, again, I mean another Black man or woman killed at the hands of police using excessive force."

Williams called on officers "to be held accountable, charged and convicted."

"In the middle of the Derek Chauvin trial for murdering my uncle George Floyd, in snow and freezing weather conditions, we came to stand with this family," he said. "It’s unacceptable. When is enough enough?"

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