FACTBOX-Key moments from 10th day of witness testimony at Chauvin trial

LINDSEY THOMAS, FORENSIC PATHOLOGIST Dr. Lindsey Thomas, an assistant medical examiner in the Hennepin County medical examiner's office until she went into "semi-retirement" in 2017, said the sheer volume of videos of Floyd's arrest helped support Baker's findings. "There's never been a case I was involved in that had videos over such a long time frame and from so many different perspectives," Thomas testified, saying the videos made it clear physical signs associated with opioid overdose were not present in Floyd's death.

The county medical examiner testified in the murder trial of former Minneapolis police officer Derek Chauvin on Friday that he determined George Floyd died from officers pinning him to the ground and that drugs in his system did not directly cause his death. Chauvin, who is white, pressed his knee into the neck of Floyd, a 46-year-old Black man in handcuffs, for about nine minutes on May 25, 2020, a scene that ignited protests in many cities in the United States and around the world.

Here is a look at some important moments from the 10th day of witness testimony in the trial: DR. ANDREW BAKER, MEDICAL EXAMINER WHO PERFORMED FLOYD AUTOPSY

Baker, Hennepin County's chief medical examiner, described how he performed the autopsy, including extra steps to cut into the flesh around where Floyd's wrists were handcuffed and along his back to look for bruising from the arrest. Chauvin and three other officers were attempting to arrest Floyd on suspicion of using a fake $20 bill to buy cigarettes at a grocery store. They were fired the following day. Baker said he noted Floyd's heart disease and the fentanyl and methamphetamine found in his blood on the death certificate because they may have played a role in the death, but "were not direct causes."

"Mr. Floyd's use of fentanyl did not cause the subdual or the neck restraint, his heart disease did not cause the subdual or the neck restraint," Baker told the jury, referring to the way police pressed on Floyd. Baker ruled that Floyd's heart stopped beating and his lungs stopped working because Chauvin and other officers pinned him to the ground in a way that starved his body of oxygen.

Prosecutor Jerry Blackwell asked Baker why he did not photograph Floyd's heart, anticipating questions by Chauvin's lawyer on whether heart disease caused Floyd's death. "I don't normally photograph organs that appear to be perfectly normal unless there's some reason to," Baker said.

DR. LINDSEY THOMAS, FORENSIC PATHOLOGIST Dr. Lindsey Thomas, an assistant medical examiner in the Hennepin County medical examiner's office until she went into "semi-retirement" in 2017, said the sheer volume of videos of Floyd's arrest helped support Baker's findings.

"There's never been a case I was involved in that had videos over such a long time frame and from so many different perspectives," Thomas testified, saying the videos made it clear physical signs associated with opioid overdose were not present in Floyd's death. While physically examining a body can be helpful in determining a cause of death, Thomas said other records and inquiries can sometimes be even more illuminating.

Thomas said the videos made clear this was not a sudden death from a heart attack. She said the videos also did not show signs of a fentanyl overdose "where someone becomes very sleepy and then just sort of gradually, calmly, peacefully stops breathing." Jurors were handed envelopes containing photographs of Floyd's corpse. Thomas drew their attention to abrasions on the left side of Floyd's face and his shoulder - wounds she called "consistent with what it looks like on the video, that he's struggling to push himself into a position where he can breathe."

Eric Nelson, Chauvin's lead lawyer, got Thomas to agree that being prone was not in itself sufficient to kill someone, noting that massage therapists sometimes have clients lie face down. "I could be laying by the pool in Florida on my stomach in the prone position – not inherently dangerous?" Nelson asked.

"Right," Thomas replied. Nelson asked her about hypothetical scenarios, with Floyd being found dead in different circumstances in which police were not involved.

Blackwell, the prosecutor, subsequently asked Thomas, "George Floyd was not laying by the pool on his stomach in Florida, was he?" Thomas agreed, saying: "There's no evidence to suggest he would have died that night except for the interactions with law enforcement."

(Compiled by Brendan O'Brien in Chicago; Editing by Will Dunham)