鶹ý

Forensic Pathologist Breaks Down George Floyd's Death

— An outside perspective on viral videos, autopsy findings, and the medical examiner's role

Last Updated June 8, 2020
MedpageToday
A photo of George Floyd

On May 25, 2020, George Floyd, 46, died following his arrest and restraint, handcuffed and prone, at the hand of Minneapolis Police Department officers. Eyewitness video of Officer Derek Michael Chauvin kneeling on Floyd's neck went viral on social media. I'm first going to take you through the videos of George Floyd's death so you can see them through the eyes of a forensic pathologist. I currently perform forensic autopsies in California, and I analyze videos of officer-involved deaths as a part of that job. I played no part in this death investigation.

Autopsy means "see for yourself" -- but sometimes the autopsy doesn't show you everything. A forensic pathologist cannot accurately determine the cause of death and the by looking at the autopsy findings alone. That's because there are several ways to kill people without causing devastating injury to the internal organs. Asphyxia from neck and chest compression is one of those ways.

The Washington Post has that captured George Floyd's first interactions with the police. In it, you can see two police officers. One talks to Floyd for over two minutes before he tries to remove him from the vehicle. Floyd then briefly struggles with both officers and appears to nearly collapse at 03:14- 03:17. As an officer walks Floyd, who is handcuffed behind his back, over to the wall, Floyd's gait is uneven. He is talking to the officer, and they appear to continue the dialogue as the officer assists Floyd in sitting down against the wall. The officer even makes some notes in his notepad. The officer lifts Floyd back to his feet by pulling up on his arms, which causes Floyd to grimace and turn his face toward the officer. His gait is again lurching and uneven as the two officers walk him across the road to their patrol vehicle. When they reach it, he falls to the ground for a moment.

image
George Floyd's interaction with police

image
George Floyd's interaction with police

The fact that Floyd appears to be talking to the officer and the officer is taking notes suggests that Floyd is engaging in dialogue. The gait disturbance suggests that Floyd may have been under the influence of alcohol or some other drug that could affect his balance. The grimace as he is being handled suggests that the cuffs are on too tight or that he is in pain during this encounter as the officer pulls up on his cuffed arms. Here's what I don't see: I don't see someone who appears to be suffering from excited delirium when drugs of abuse can cause agitation, hyperthermia, and sudden death. Floyd is not naked or dressed inappropriately for the weather. He does not appear to be sweating profusely. He does not appear to be agitated or violent.

image
Bystander video of police kneeling on George Floyd

A short shows three police officers kneeling on Floyd while another stands at his head. They appear to be exerting pressure on his neck, torso, left (still handcuffed) arm, and legs. Pressure on the torso can limit chest rise, and added pressure on other parts of the body can decrease cardiac return (the volume of blood coming back from the limbs).

Looking at a longer, posted on Facebook, the first thing I notice is that Floyd's voice sounds gravelly, and he repeatedly says, "I can't breathe." EMS and police are sometimes trained that anyone who says "I can't breathe" is lying -- because if you can speak, you can breathe. This is not true, and there are many reasons why people might say "I can't breathe" and still be in medical distress. These reasons include increasing fatigue of respiratory muscles; blockage of pulmonary blood flow; incomplete airway obstruction; and acidosis, a buildup of acid in the blood which triggers an increased breathing rate and causes the sensation of shortness of breath.

At the start of the video, Floyd has already appeared to have lost bladder function. This can be a sign of medical distress. Floyd specifically mentions "the knee in my neck," a coherent statement and not the grunting and screaming we typically hear in deaths from excited delirium. As this video starts, Officer Chauvin already has his knee pressed on Floyd's neck, and you can see that pressure is being applied to the part of his anatomy that contain the carotid arteries and jugular veins. Floyd first appears to become unresponsive at 4:01. He stops talking, his eyes close, and his face is still. Bystanders start noticing this at 4:45. At 6:58 an officer checks his pulse. Officer Chauvin's knee doesn't come off Floyd's neck until 7:55, over 3 minutes after Floyd first seems to have gone unconscious.

The in the case stated, "The autopsy revealed no physical findings that support a diagnosis of traumatic asphyxia or strangulation," and that "Floyd had underlying health conditions including coronary artery disease and hypertensive heart disease. The combined effects of Floyd being restrained by the police, his underlying health conditions, and any potential intoxicants in his system likely contributed to his death." In contrast, the stated that "the cause and manner of death is currently pending further testing."

Why the difference?

Charging documents are usually written by attorneys based on information obtained from police officers and a representative of the medical examiner's office. They should not be interpreted as the definitive result of the autopsy, and they are frequently inaccurate. The headlines that suggested that asphyxia had been ruled out by the medical examiner were wrong.

So were the ones that said that Michael Baden, MD, did an "independent autopsy." Baden is a retained expert and is being paid for his services by Floyd's family. He is not independent. The Hennepin County Medical Examiner, which is paid by taxpayer money, is the only independent agency here. They did the first, legally-mandated autopsy, and collected the evidence. The medical examiner's office is not an arm of law enforcement. If a retained expert finds something at autopsy that is not favorable to the client's legal case, the client doesn't have to disclose that expert at all. Everything the medical examiner does and all the evidence they collect is a public record. None of their findings, no matter what they reveal, can be suppressed.

Furthermore, a "second autopsy" is always fraught with problems. The process of performing the first autopsy causes "autopsy artifact" -- severed blood vessels, dissected organs, and even broken bones -- that the second autopsy pathologist may not be able to distinguish from inflicted injury. When I perform a forensic autopsy on someone we suspect might have died of asphyxia, I will frequently keep the entire neck block (the windpipe, blood vessels, and surrounding organs and structures of the throat) in a stock jar in the morgue, as evidence. I may even save large sections of the heart and brain for specialized testing. These materials would not be available to a private-practice pathologist hired to perform a second autopsy.

If Baden looked at Floyd's corpse after a thorough forensic autopsy, there would have been little left for him to examine. Keep in mind that he also does not have access to all the evidence in the case, such as the medical records, witness statements, body camera videos, or police reports.

Following a press conference on June 1 about the second autopsy, Baden admitted that portions of Floyd's organs were , and that he didn't have access to the results from toxicology testing. Soon after, the Hennepin County Medical Examiner issued a , and subsequent to that, the , which indicated that the cause of death was "cardiopulmonary arrest complicating law enforcement subdual, restraint, and neck compression," and that the manner of death was homicide. They listed arteriosclerotic and hypertensive heart disease, fentanyl intoxication, and recent methamphetamine use as other significant conditions contributing to death.

This means that Floyd stopped breathing and his heart stopped beating (cardiopulmonary arrest) because of the injury caused by his restraint in the custody of law enforcement officers, to include asphyxia from neck compression. Asphyxia means that there is a lack of oxygen going to the brain. It can happen from obstruction of the airway, restriction of breathing from compression of the neck or chest, or the prevention of blood flow to the brain by collapsing the blood vessels in the neck. It can also happen from the replacement of oxygen in the blood by carbon monoxide, or depletion of oxygen in the atmosphere, like in a fire. "Cardiopulmonary arrest" is not a heart attack. Online sources that imply that the medical examiner is covering up George Floyd's death by calling it a "heart attack" are wrong.

The death certificate's "other significant conditions" -- Floyd's natural heart disease and the presence of drugs of abuse in his tested blood -- do not excuse the officers, nor should they cause anyone to blame the victim. They are there on the death certificate because those findings, in the opinion of the medical examiner, would have made his death more likely. They are not the cause of death. The cause of death is police restraint.

At the end of their press release, the Hennepin County Medical Examiner adds the following important reminder: "Under Minnesota state law, the Medical Examiner is a neutral and independent office and is separate and distinct from any prosecutorial authority or law enforcement agency." Regardless of whether experts agree with their interpretation of the evidence, they were the first to collect it, and because they did their job, that evidence is now available for public scrutiny in a court of law.

, is a forensic pathologist and CEO of PathologyExpert Inc. Her New York Times bestselling memoir, co-authored with her husband, writer T.J. Mitchell, is . They've also embarked on a medical-examiner detective novel series with , now available from Hanover Square Press.