Two doctors who carried out an independent autopsy of George Floyd, the black man whose death in Minneapolis police custody last week triggered nationwide protests, said on Monday that he died from asphyxiation and that his death was a homicide.
The doctors also said Floyd had no underlying medical conditions that contributed to his death - and that he was likely dead before he was placed into an ambulance.
That contradicts the initial findings of the official autopsy by the Hennepin County Medical Examiner, which was cited in the court charging document against the police officer who drove his knee into Floyd's neck for several minutes.
Those initial findings said there was no evidence of traumatic strangulation. It also said coronary artery disease and hypertension also likely contributed to Floyd's death. The county's full autopsy report has not yet been released.
Later on Monday, the medical examiner declared Floyd's death was a homicide.
The evidence is consistent with mechanical asphyxia as cause of death and homicide as manner of death, said Dr Allecia Wilson of the University of Michigan, one of the two forensic doctors who performed an independent autopsy.
Bystander video showed Floyd pleading to be let up and saying repeatedly that he couldn't breathe as a police officer Derek Chauvin kept his knee firmly pinned into Floyd's neck for nearly nine minutes. Two other officers applied pressure with their knees to Floyd's back.
Chauvin, who is white and has been fired from the Minneapolis police department, was hit with third-degree murder and manslaughter charges last week.
But Dr Michael Baden, who also took part in the independent autopsy at the behest of Floyd's family, said that the two other officers' actions also caused Floyd to stop breathing.
We can see after a little bit less than four minutes that Mr Floyd is motionless, lifeless, Baden said, adding he found no underlying health conditions in Floyd that caused his death.
Baden has worked on several high-profile cases, including the 2014 death of Eric Garner, a black man who died after being choked by police in New York City.
Baden shot down the argument that if Floyd could speak then he could breathe.
Many police are under the impression that if you can talk, that means you're breathing.
That is not true, Baden said. I am talking right now in front of you and not taking a breath.