David Pleoger, a retired Minneapolis Police Department sergeant who was on duty the night of Floyd's death, testified that Chauvin's restraint of Floyd should have ended when he was "no longer offering up any resistance" to the officers.
"It would be reasonable to put a knee on someone's neck until they were not resisting anymore but it should stop when they are no longer combative," Pleoger said.
Pleoger also told the court that Chauvin had told him in a phone call after Floyd's death that Floyd had sustained an injury to his nose or mouth and later had a "medical emergency" that prompted a call for an ambulance.
During the first day of the trial on Monday, defense attorney Eric Nelson said that Chauvin "did exactly what he had been trained to do during the course of his 19-year career."
Pleoger testified that police department policy requires officers to call an ambulance and render aid while waiting for an ambulance in addition to positioning the subject on their side so they can breathe better.
"If you restrain somebody or leave them on their chest and stomach for too long, their breathing can become compromised and so you'd want to get them up out of that position after a while so they don't suffer breathing complications," Pleoger said.
Acquaintances of Floyd's also took the stand early Thursday and spoke of the 46-year-old man's character and his life in Minneapolis.
Among those testifying Thursday was Floyd's girlfriend Courteney Ross, who said Floyd had tested positive for COVID-19 two months before he died during the arrest by Chauvin and three other officers in May 2020.
Ross also spoke about how she and Floyd struggled with opioid addiction. She said he had been hospitalized for an overdose in March.
Ben Crump and Antonio Romanucci, civil rights lawyers who have represented Floyd's family, issued a statement following Ross' testimony, saying that despite the fentanyl in Floyd's system at the time of his death, he had been "walking, talking, laughing and breathing just fine before Derek Chauvin held his knee to George's neck."
They said Floyd had built up a "tolerance" to having fentanyl in his body.
"Tens of thousands of Americans struggle with self-medication and opioid abuse and are treated with dignity, respect and support, not brutality. We fully expected the defense to put George's character and struggles with addiction on trial because that is the go-to tactic when the facts are not on your side. We are confident that the jury will see past that to arrive at the truth -- that George Floyd would have lived to see another day if Derek Chauvin hadn't brutally ended his life in front of a crowd of witnesses pleading for his life."
Prosecutors also questioned a two paramedics who treated Floyd at the scene and transported him to the hospital. Seth Zachary Bravinder said when he arrived, he observed that Floyd wasn't breathing.
He said that en route to the hospital, he stopped the ambulance to help his colleague treat Floyd because his heart "flatlined."
"It's not a good sign," Bravinder said. "Basically just because your heart isn't doing anything at that moment. There's not -- it's not pumping blood. So it's not ... a good sign for a good outcome."
The second paramedic, Derek Smith, said he believed Floyd was dead when he arrived at the scene.
"I walked up to the individual, noticed he wasn't moving. I didn't see any chest rise or fall on this individual," he said.
Smith added that he did all he could to revive Floyd.
"He's a human being and I was trying to give him a second chance at life," he said.
Capt. Jeremy Norton of the Minneapolis Fire Department said when he saw Floyd upon entering the ambulance "he was an unresponsive body on a cot."
Norton added that he filed a report with his supervisors after following the ambulance to the hospital.
"I was aware that a man had been killed in police custody and I wanted to notify my supervisors to notify the appropriate people above us in the city, in the fire department and whomever else and then I also wanted to inform my deputy that there was an off-duty firefighter, who was a witness at the scene," he said.During testimony Wednesday, jurors heard from an employee of the store that Floyd visited shortly before his death and saw new video of the arrest from the market.
The store clerk, who called police over a questionable $20 bill Floyd had used to pay for cigarettes, was emotional during his testimony Wednesday and told jurors he suspected Floyd was already dead by the time the ambulance arrived.
Chauvin, who faces conviction on a murder or manslaughter charge, kept his knee pressed down on the back of Floyd's neck for several minutes during the arrest before he died.