Follow the latest trial updates here. Earlier coverage is below.
Testimony is now complete in the trial of Derek Chauvin, the fired Minneapolis police officer charged in George Floyd's death. The defense rested its case Thursday after Chauvin said he will not testify in his own defense. Chauvin spoke in court from the defense table just after court resumed on Thursday.
"I will invoke my Fifth Amendment privilege today," Chauvin said.
Prosecutors then re-called to the stand Dr. Martin Tobin, a pulmonologist who offered key testimony for the prosecution last week, saying Floyd died of low oxygen under the pressure of officers' weight on his neck, back and side. Thursday, Tobin rebutted some of the testimony of forensic pathologist Dr. David Fowler, who testified for the defense that Floyd suffered a heart arrhythmia due to his underlying heart disease.
Judge Peter Cahill excused the jury after Tobin's testimony. He told jurors to return at 9 a.m. Monday for closing arguments, after which they will be sequestered for deliberations.
The defense case centers around how Floyd died, which has been a key point of dispute at trial. A string of medical experts have testified for the prosecution, saying the police restraint restricted oxygen to Floyd's body and caused his heart to stop. But defense attorney Eric Nelson has argued a combination of Floyd's underlying heart disease, adrenaline and the fentanyl and methamphetamine he had ingested prior to the arrest amounted to a fatal combination. Fowler testified there were so many factors involved that he considers the manner of Floyd's death to be undetermined.
The defense launched its case on Tuesday. Testimony focused on Floyd's drug use, and a defense use-of-force expert said Chauvin was justified in restraining Floyd.
Chauvin, who was seen in disturbing videos kneeling on Floyd's neck for more than nine minutes, is charged with second-degree murder,and second-degree manslaughter.
Chauvin has pleaded not guilty. The other three officers involved are charged with aiding and abetting, and are expected to be tried jointly in August.
Dr. Tobin has completed his testimony. Judge Peter Cahill has informed the jury that testimony is now complete in the case. He informed them to come back at 9 a.m. Monday to hear closing arguments, after which they will launch deliberations.
The panel will be sequestered for the deliberation period. Cahill said some jurors have asked how much they should pack. Cahill replied the amount of time needed to deliberate is entirely up to the jury.
"If I were you, I'd plan for long, and hope for short," Cahill said.
The jury has been excused.
Pulmonologist rebuts defense expert's testimony
Tobin testified that tests on Floyd's blood indicated his oxygen saturation level was 98 percent, meaning the amount of carbon monoxide would be no more than 2 percent. He called estimations of higher carbon monoxide levels by defense expert Dr. David Fowler "simply wrong."
Tobin also rebutted Fowler's testimony that pressure on the neck would not have narrowed Floyd's hypopharynx, a small area at the lower part of the throat. Tobin said he couldn't point to any studies because "it's common sense that would happen."
"You can do it yourself if you want, you can immediately sense your upper airway is narrowing," Tobin said.
Tobin last week offered key testimony for the prosecution, saying Floyd died of low oxygen under the pressure of officers' weight on his neck, back and side. Fowler offered a differing opinion Wednesday, saying Floyd suffered a heart arrhythmia due to his underlying heart disease.
The defense has rested its case. Prosecutors have re-called pulmonologist Dr. Martin Tobin to the stand as a rebuttal witness.
Judge bans newly surfaced carbon monoxide lab tests
Outside the presence of the jury, prosecutors say they have newly discovered evidence regarding testing that was done on George Floyd's blood for carbon monoxide levels. Prosecutors want to introduce the evidence to rebut testimony from defense expert, forensic pathologist Dr. David Fowler, who suggested carbon monoxide from the squad car's exhaust as a possible contributing factor to Floyd's death.
Prosecutor Jerry Blackwell said the lab tests were discovered when the Hennepin County medical examiner who conducted Floyd's autopsy called prosecutors after Fowler's testimony.
Defense attorney Eric Nelson argued the state has known about Fowler's testimony since February and had the ability to investigate the carbon monoxide tests earlier, but did not. Nelson argued the introduction of the evidence now would be prejudicial, and if it's allowed in front of the jury, he said he would move for a mistrial.
The judge agreed the state had ample opportunity to look into the issue and denied the new evidence, saying "this late disclosure is not the way we should be operating here."
Chauvin won't testify
Court has resumed. Chauvin is speaking through a microphone, answering questions from his lawyer Eric Nelson, saying he understands he has a right not to testify.
Nelson said he and Chauvin have had several conversations about Chauvin's possible testimony, and Nelson has advised Chauvin that the decision is his own.
Nelson asked if Chauvin understands if he chooses not to testify, that the state and the court cannot "equate your silence with guilt."
"Yes," Chauvin replied.
Chauvin said he understands he could also waive the right to remain silent and testify, and that if he chose to do so he would be subject to broad cross-examination by the prosecutors.
"We have gone back and forth on the matter would be kind of an understatement, right?" Nelson asked.
"Yes it is," Chauvin responded.
Nelson said he and Chauvin had a lengthy meeting with further discussion on the issue Wednesday night, and Chauvin agreed they had. Nelson then asked whether Chauvin had come to a decision.
Chauvin said, "I will invoke my Fifth Amendment privilege today."
Carbon monoxide suggested as factor in Floyd's death
Dr. David Fowler, the forensic pathologist who testified for the defense Wednesday, found that Floyd died of a heart arrhythmia due to his heart disease. But he listed several contributing factors, including drugs and possible exposure to carbon monoxide from the squad car's exhaust.
Answering questions from prosecutor Jerry Blackwell, Fowler agreed there was no finding of carbon monoxide in Floyd's body because no tests were done. Blackwell then asked Fowler if he knew for a fact that the squad car was running at the time Floyd was restrained. Fowler replied he believed the car was running because he saw water dripping from the tail pipe.
"You simply assumed, seeing something dripping from a tailpipe, that the car had to be on?" Blackwell asked.
""It's not an assumption," Fowler replied. "It's an evaluation that in my mind indicates the vehicle was running."
Defense expert: Chauvin was justified in using force
Barry Brodd, a former police trainer, testified as a use-of-force expert Tuesday after analyzing Chauvin's actions for the defense.
He said he focused his review on the videos, use-of-force policies and training. Brodd said he believes Chauvin was justified in restraining Floyd, acting with objective reasonableness and following Minneapolis police training. He said he believes Floyd was "actively resisting" officers by struggling as he was restrained on the ground.
Defense highlights Floyd's 2019 arrest
Retired Minneapolis officer Scott Creighton was the first witness called for the defense on Tuesday. He testified he pulled his weapon when Floyd wouldn't show him his hands during a traffic stop in 2019. In body camera video played in court, Creighton raises his voice and uses an expletive as he commands Floyd, a passenger in a car he pulled over, to show him his hands. Floyd can be heard asking the officer not to shoot him.
"I'm not going to shoot you if you put your hands on the dash, it's the last time I'm going to tell you, it's simple," Creighton says on the video. "He keeps moving his hands around, he won't listen to what I have to say."
Later, a paramedic testified Floyd admitted he had swallowed pills during the arrest, and said his blood pressure was so high she sent him to the hospital. Watch a recap of earlier testimony below.
Chauvin is charged with second-degree murder,and second-degree manslaughter.
In order to convict Chauvin of second-degree murder, prosecutors will need to prove beyond a reasonable doubt that Chauvin caused Floyd's death while committing or attempting to commit a related felony, in this case third-degree assault. To convict the former officer of third-degree murder, prosecutors must convince the jury that Chauvin caused Floyd's death during an act that was "eminently dangerous to others and evincing a depraved mind, without regard for human life."
The third-degree charge was initially dropped by Judge Cahill, but was re-instated earlier this month after an appeals court handed a win to prosecutors.
To convict Chauvin of second-degree manslaughter, prosecutors will need to prove beyond a reasonable doubt that Chauvin caused Floyd's death by "culpable negligence," meaning he created unreasonable risk and consciously took a chance of causing death or serious harm.
Prosecutors do not need to prove that Chauvin intended to cause Floyd's death. Since police officers are authorized to use force, prosecutors must prove that the force Chauvin used against Floyd was unlawful.
In Minnesota, second-degree murder carries a maximum sentence of 40 years in prison.