A medical expert who specializes in pulmonology has told jurors in Derek Chauvin‘s murder trial that the force of George Floyd being pinned to the ground was like a ‘surgeon had gone in and removed a lung’.
Dr Martin Tobin, who has been a lung and critical care specialist for more than 45 years, testified on Thursday that he believed Floyd’s cause of death was due to a lack of oxygen that damaged his brain and caused his heart to stop when he was pinned to the street by Minneapolis police officers.
During his testimony, Dr Tobin analyzed – based on his medical expertise – how Floyd would have been unable to breathe based on videos he had viewed from the scene and medical records.
Floyd’s cause of death has become the most contested issue of Chauvin’s trial so far with the defense claiming he died as a result of a drug overdose.
When asked if Dr Tobin, based on his medical expertise, had determined a cause of death for Floyd after viewing videos from the scene, he said: ‘Mr Floyd died from a low level of oxygen.
‘The cause of low level of oxygen was shallow breathing. Small breaths that weren’t able to carry the air through his lungs.’
Dr Tobin said there were four forces that caused the fatal shallow breathing: The fact that Floyd was face down on the street, had his hands cuffed behind his back and had a knee on his neck and on his back.
Dr Martin Tobin was the first to testify for the prosecution on Thursday on what has become the most contested issue of Chauvin’s trial so far: Floyd’s cause of death
Dr Tobin referred to this graphic to show how Floyd was restrained by the officers following his arrest
In one horrific moment, he told the court that the impact of the pressure of the officers and handcuffs rendered movement so impossible that ‘basically on the left side of his lung it was almost to the effect of if a surgeon had gone in and removed his lung.’
The court was shown a graphic – which Dr Tobin called a ‘snapshot in time’ – depicting the officers’ positions on Floyd before he died.
Dr Tobin explained he focused on the first 5 minutes and 3 seconds as that was the point at which Floyd started to show signs of brain damage.
Chauvin, 45, is accused of killing Floyd by pinning his knee on the 46-year-old black man’s neck for 9 minutes, 29 seconds, as he lay face-down in handcuffs after being detained for using an alleged counterfeit $20 bill to buy cigarettes
Using this graphic, Dr Tobin told jurors of the impact those four forces would have had on Floyd’s death.
He said the impact of the handcuffs and the street conspired to hold Floyd’s chest in ‘a vice’.
‘It the positioning [of the handcuffs] then how he’s manipulated by both officers Chauvin and Keung, and they’re pushing the handcuffs into his back and pushing them high,’ Dr Tobin said.
‘Then on the other side you have the street and he’s against the hard asphalt street so the way they’re pushing down on the handcuffs, onto the street… It’s like the left side is in a vice, squeezed in from both sides, from the street at the bottom and the handcuffs and how they’re being held, where they’re being pushed.’
This meant that Floyd’s lungs and chest could not move front to back movement – a vital motion of breathing, he said.
Chauvin’s defense attorney Eric Nelson has previously made much of what he describes as ‘camera perspective bias’, using the notion to suggest that Chauvin’s knee was not on Floyd’s neck all, if any, of the time.
Dr Tobin, however, said that by his calculations Chauvin’s left knee was ‘virtually on his neck for the vast majority of the time.’
‘It’s more than 90 percent of the time,’ he said.
Dr Tobin relied on several images during his testimony. He said Chauvin was exerting 91.5lbs of pressure directly down on his neck
As for his right knee, Dr Tobin said that it was on Floyd’s back for 57 percent of the time – the time when he could get a clear view.
‘At other times it was placed on his arm and then rammed into Mr Floyd’s left chest so really if you’re making a distinction on whether his knee is on the chest per se or on the left arm and rammed into the chest, from the point of view of breathing the effects are very similar.’
At certain points as Floyd struggled to breathe Chauvin was exerting 91.5lbs of pressure directly down on his neck, Dr Tobin told the court.
He made that calculation based on it being half of Chauvin’s bodyweight and half of his gear weight and said that at certain points all of this was brought to bear on Floyd as the toes of his left foot were off the ground and therefore bearing no weight.
When Chauvin’s foot was on the ground he calculated the pressure as 86.9lbs as some of the shank weight was supported by the toes at that point.
Of the different pressures placed on Floyd’s neck, back and chest he said: ‘It’s complex but all coming to the same point.’
Chauvin, 45, is charged with murder and manslaughter after being accused of pinning his knee on Floyd’s neck for nine minutes and 29 seconds in May last year
Chauvin, 45, is charged with murder and manslaughter after being accused of pinning his knee on Floyd’s neck for nine minutes and 29 seconds in May last year.
He has pleaded not guilty, arguing that he did only what he was trained to do in his 19 years as an officer.
Chauvin was fired by the city’s police department the day after he was captured on video kneeling on a handcuffed Floyd’s neck after he was detained for using an alleged counterfeit $20 bill to buy cigarettes.
The trial so far has been filled with testimony from a number of Minneapolis police officers who rejected Chauvin’s actions in restraining Floyd.
A use-of-force instructor testified that officers were coached to ‘stay away from the neck when possible’ and other experienced officers, including the police chief, said Floyd should not have been kept pinned to the pavement for so long with his hands cuffed behind his back.
Other testimony so far during the trial has come from emotional witnesses, including Floyd’s girlfriend Courteney Ross and bystanders who saw everything unfold.
In addition to the testimony, the prosecution has also introduced multiple videos, including footage from Chauvin’s body camera, and images of EMTs trying to resuscitate Floyd in an ambulance.