Cardiologist Jonathan Rich earlier told the court that in his professional opinion, George Floyd did not die of a heart attack or drug overdose.

Watch the moment below.

"So if [Floyd] had gotten into the squad car he would have survived?" asks Nelson.

"Correct," says Dr Rich, adding that being in the prone position is inherently dangerous.

Floyd had told officers he was claustrophobic and did not want to be placed in the car.

Last week, the Minneapolis police chief testified that suspects in counterfeit money cases - as Floyd was - would normally be issued with a citation and not arrested.

Prosecutors for the state are now asking questions about blocked arteries in Floyd's body.

The Chicago cardiologist has testified that he reviewed George Floyd's medical records going back to 2018.

Earlier he said that a prior emergency room visit showed that Floyd had been prescribed blood pressure medication. He says that it is unclear whether he was actually using the medication at the time of his death.

Some of the testimony in the trial has been difficult to watch. It has been even more so for black Americans, some of whom have been traumatised by the videos of Floyd's arrest.

In interviews with the BBC, several black activists in Minneapolis have spoken about their exhaustion.

Watch our video below to see what they told us.

"What is a safe dose of methamphetamine?" asks defence lawyer Nelson, clarifying he means "illicit" meth.

"I would never consider any drug that is not prescribed and is off the street to be safe," the witness replies.

The drug, Dr Rich says, can contribute to coronary heart disease and can restrict blood vessels.

A toxicology report released last June said that Floyd had the painkiller fentanyl and the drug methamphetamine in his system.

The defence team has been arguing that Floyd's pre-existing health issues and drug use were the main factors leading to his death, not Chauvin's actions.

We're back from break and defence attorney Eric Nelson is now questioning cardiologist Dr Jonathan Rich.

He's beginning with questions about coronary disease.

A jury of 14 people - including two alternates - were sworn in on the first day of the trial.

These local citizens are the ones who will hand out a verdict in this case.

Their identities have been kept anonymous for their safety. They will not be shown on camera during the trial.

But what do we know about them?

The group includes three black men, one black woman, three white men, six white women and two multi-racial women, according to the court.

They come from different backgrounds and range in age from their 20s to their 60s.

The oldest member is a black grandmother in her 60s who said she stopped watching the infamous video of Floyd's death because "it just wasn't something I needed to see". She also claimed she used to live 10 blocks from where he had died.

Read more about the jury here.

Over the last two weeks, we've been hearing from the team prosecuting Derek Chauvin and their witnesses. Prosecutors are expected to wrap up soon - possibly as early as today.

Then, it will be time for the defence to start making their case.

Chauvin's lead defence lawyer, Eric Nelson, has already given us some indication of their arguments.

In his opening statement and cross-examinations, Nelson has focused on three main points:

1) Necessary force

He said Chauvin's use of force during the arrest of Floyd was "unattractive but necessary", and that the former officer was simply following his training.

Nelson has portrayed Chauvin's kneeling on Floyd as a control move that is approved by the police department.

2) Other causes

The defence team will also likely emphasise that there were no signs of asphyxiation or bruising on Floyd's neck, according to one autopsy.

Nelson has also already argued that Floyd's pre-existing health issues and drug consumption were the main contributing factors to his death.

3) A hostile crowd

Nelson has suggested that the crowd of people that gathered around Chauvin distracted him during the arrest.

"They are screaming at them, causing the officers to divert their attention from the care of Mr Floyd to the threat that was growing in front of them," Nelson said.

For a flavour of Chauvin's defence, you can watch Nelson's opening statement below:

"I counted the number of minutes that he was on the ground pulseless without any CPR," says Dr Rich, who points out that CPR was not given until paramedics had loaded Floyd onto an ambulance.

He explains that for every minute that passes without basic life support and CPR, "there is approximately 10 to 15% less chance of survival".

Asked by prosecutors whether Floyd would have survived if CPR had been performed, Dr Rich answers: "Yes, I believe he would have lived."

With that, the court takes its first break of the morning.

Both fentanyl and methamphetamine were found in George Floyd's system, and the defence has argued either of those drugs may have contributed to his death.

Prosecutorial witness Dr Rich refutes this claim, telling the court: "I feel it played no substantive role at all."

"All things considered, it was a very relatively low level of methamphetamine in his system," he adds.

He says Floyd's death was "entirely preventable".

"I see no evidence at all to suggest a fentanyl overdose caused Mr Floyd's death," says Dr Rich, who adds that he has viewed Floyd's toxicology report.

"It appeared to me that Mr Floyd, who was an acknowledged frequent chronic user of opioids... had developed a high degree of tolerance," he continues.

Dr Rich says that he reviewed one case where Floyd went to a hospital emergency room after taking the opioid Percocet. He tells the court in that case, Floyd told health workers he took eight pills in two hours, but had no side effects.

In the videos of his 25 May arrest, Dr Rich says he "didn't see any of the signs of an opiate overdose".

He says that he often encounters patients suffering opioid overdoses and that they are "usually extremely lethargic, oftentimes unarousable".

"They're not talking to you," he says. "If they are talking they're usually having slurred speech. I saw the opposite with Mr Floyd.

"He was alert, he was awake, he was conversant, he was walking."

Prosecutors have again asked cardiologist Dr Rich if he saw any evidence that Floyd suffered a heart attack. He responds: "None whatsoever."

The prosecutor then questions if he saw any evidence of a "silent heart attack".

Dr Rich first explains that a silent heart attack is a condition where it "looks like someone had a heart attack but there were no clinical signs that suggest it".

He says it is relatively uncommon and more prevalent in patients with diabetes who have lost sensation in certain parts of their body.

Dr Rich testifies that Floyd did not suffer a silent heart attack either.

Image source, Getty Images

The trial has largely focused on the moments leading up to and during the arrest of George Floyd outside the Cup Foods shop in Minneapolis.

Here's a breakdown of how Floyd's final moments unfolded:

20:01 -The store’s teenage employee calls 911 after believing Floyd used a counterfeit bill. He says Floyd appears "drunk" and "not in control of himself"

20:08 - Two officers arrive. Floyd is sitting in a car parked around the corner with two other people. Officer Thomas Lane approaches the car. Floyd appears to be co-operative at first. Lane asks Floyd to show his hands before ordering him out of the vehicle. Lane, with his gun drawn, pulls Floyd out of the car.

A struggle between officers and Floyd ensues when they try to move him into a squad car.

20:14 - Floyd falls to the ground, telling police he is "claustrophobic". This is when Derek Chauvin arrives on scene.

20:19 - Chauvin pulls Floyd away from the car, and Floyd falls to the ground. As Floyd lies face down, in handcuffs, Chauvin places his left knee between Floyd’s head and neck. For more than nine minutes, according to prosecutors, he keeps it there, even as Floyd says he cannot breathe.

20:27 - Chauvin removes his knee from Floyd’s neck. Paramedics move Floyd, who is motionless, onto a gurney.

Read more here.

Dr Rich says that even though he never physically examined George Floyd in person, "we can do a lot by video assessments".

The cardiologist says he saw "no acute distress" from medical problems and no struggle for oxygen in his initial interactions with the officers.

He adds that there was no swelling, dizziness or any abnormal response from Floyd until he was restrained on the ground "in a life-threatening manner".

Floyd's deterioration happened "gradually and slowly" as he was pinned - further proof that he was losing oxygen and not having a heart attack, Dr Rich says.

Image source, Court TV

Wearing a mask and a grey suit, Chauvin scribbles notes on a yellow notepad as cardiologist Dr Rich delivers his testimony about the cause of Floyd's death.

Chauvin has not spoken in court, but the former police officer has appeared engaged throughout the trial. As witnesses speak, he listens intently, occasionally furrowing his brow and taking almost constant notes.

Chauvin will get a chance to defend himself at court - but it's not yet clear if he will take the stand as a witness himself.

Dr Rich says that Floyd may have had high blood pressure due to an "exceptionally strong heart" that rapidly pumped blood throughout his body.

"The heart is a muscle," he explains, adding that exercise makes it stronger. He says that like other muscles, the heart can get "tired out" over time and does require treatment, but that "is not, in and of itself, a heart condition".

The physician's testimony is an attempt by the prosecution to undercut the defence's claim that Floyd died of a heart attack caused by poor health and underlying conditions.

Image source, Pool

Today's witness, Dr Jonathan Rich, echoes what we heard last week: that Floyd's death was caused "by a lack of oxygen" and was due to "the restraint and positional asphyxiation that he was subjected to".

The defence has suggested that Floyd may have died from a heart attack.

Dr Rich says he reviewed Floyd's medical records, the autopsy and videos of his death and could conclude: "George Floyd did not die from a primary cardiac event and he did not die from a drug overdose."

He added that Floyd had three medical problems: hypertension, high blood pressure - as well as anxiety - and struggles with substance abuse.

But he said Floyd was never diagnosed with heart disease when alive and he found no reports of heart murmurs or abnormal heart rhythms when looking through his medical files.

Earlier this morning, Judge Cahill mentioned that he expects arguments to wrap up by the end of the week.

"We’ll sequester them on Monday when we anticipate doing closings," he said of the jury, while denying a request from the defence to hold jurors in isolation.

We're now on the eleventh day of the trial of Derek Chauvin.

Prosecutors, who are still calling witnesses, are permitted two weeks to make their case against the ex-officer.

The defence is also given two weeks, but based on the judge's remark, they may only use one week to respond to the prosecution.

Tara McKelvey
BBC News, Minneapolis

Image source, Reuters

For black residents of Minneapolis, the news of Daunte Wright’s death was familiar in a frightening and infuriating way.

More than 50 black people have died in the state during an interaction with police officers since 2000, according to the Star Tribune newspaper, external.

Mothers of slain children have explained to me what it was like to fear the police, and despise them, too.

One woman, a makeup artist who grew up near Cup Foods, the place where Floyd died, said she used to watch police officers drive past her and her friends, patrolling the neighbourhood.

The officers, she said, had facial expressions that were blank and unseeing, and she and her friends tried to give the officers a wide berth.

Over the past year, she has done more to express her anger, and her views. Like thousands of others in this city, she has taken to the streets to protest against the police, and to try and prevent more shootings.

The jury has been seated and the prosecution's first expert witness of the day, Dr Jonathan Rich, has taken the stand.

He begins by describing his background as a cardiologist at Northwestern Memorial Hospital in Chicago, Illinois.

He says that he is there today to give his opinion as to how Floyd died. He also notes that this is his first time testifying in a trial.

Eric Nelson, Chauvin's defence attorney, has asked that the jurors be sequestered for the rest of the trial due to the unrest that erupted in the nearby Brooklyn Center suburb last night over another police shooting of a black man.

Jurors are currently required to be partially sequestered, meaning they will only be kept isolated after arguments are finished and they must decide on their verdict.

Each day they are escorted into the courthouse as a group.

"I would note for the court we have at least one juror that is a resident of that city, and other jurors that have a connection to Brooklyn Center," Nelson says.

He tells the judge that he wants the jurors questioned on what they know about the shooting and protests last night.

"Given that this is a high profile case, this is a case that evokes a lot of emotion for a lot of people, ultimately your honour, the question becomes 'will the jury be confident to make a decision regardless of the potential outcome of their decision?'"

He adds that the protests, although part of a different case, "sets the stage for a juror to say I'm not voting not guilty because I'm concerned about the outcome".

Lawyers for the state say they oppose completely isolating the jury, saying: "World events happen. News events happen in the state."

Judge Cahill denies the motion to sequester and question the jury, saying "this is a totally different case".