Derek Chauvin waives right to give evidence in George Floyd murder trial

Both the prosecution and defence rested their case at the murder trial with closing arguments scheduled for Monday

Former Minneapolis policeman Derek Chauvin waived his right to give evidence about his part in the deadly arrest of George Floyd in May, as both sides rested their cases at his murder trial, the most high-profile police misconduct case in decades.

"I will invoke my Fifth Amendment privilege today," Mr Chauvin, 45, said in a hearing before the jury was brought in on Thursday morning, referring to the constitutional right against self-incrimination.

They were his most extensive remarks since his trial began with jury selection on March 8.

The defence told Hennepin County District Judge Peter Cahill it would call no more witnesses after two days of evidence and rested its case, which has focused on raising doubts about what caused Floyd's death.

It is rare for defendants to take the stand in criminal cases because they face intense cross-examination by prosecutors and risk undermining their case and credibility.

After a short appearance by a rebuttal witness, prosecutors from the Minnesota attorney general's office also rested their case.

Judge Cahill said jurors would hear closing arguments on Monday before receiving the case for deliberations. They will be sequestered at a hotel in a city; National Guard troops will patrol the centre and shop windows will be boarded up.

"If I were you, I would plan for long and hope for short," Judge Cahill told jurors on the question of how much to pack.

Mr Chauvin, who is white, was seen in a bystander's video kneeling on the neck of Floyd, 46, a black man in handcuffs, for more than nine minutes. Floyd was accused of using a counterfeit $20 bill to buy cigarettes.

The footage of his death sparked global protests against the disproportionate use of force by police against black people.

His lawyers called an expert on the use of force to tell the jury that Mr Chauvin's use of force was appropriate, contradicting the Minneapolis police chief, who testified that it far exceeded an appropriate response.

They also called a forensic pathologist, former Maryland chief medical examiner Dr David Fowler, who said Floyd, whose death was ruled a homicide at the hands of the police, really died of heart disease, and that the exhaust fumes of the adjacent police car may have also poisoned him.

Dr Martin Tobin, a pulmonologist who testified as an expert witness for prosecutors, returned to the stand Thursday as a rebuttal witness in an effort to undermine Dr Fowler's evidence about carbon monoxide poisoning.

Prosecutors also said they had been contacted by Dr Andrew Baker, the Hennepin County chief medical examiner who performed the autopsy on Floyd, to disclose previously unpublished test results that showed normal carbon monoxide levels in Floyd's blood.

The judge said prosecutors had been notified by the defence earlier this year that Mr Chauvin would advance a theory of carbon monoxide poisoning. And so he denied the request to admit the new evidence, saying it was too last-minute in a way that was prejudicial to Mr Chauvin. Judge Cahill warned prosecutors that if Dr Tobin even mentioned the existence of the results, he would declare a mistrial.

Dr Tobin was questioned by prosecutors for only a few minutes, telling jurors that previously shared data showed that the level of carbon monoxide was "within the normal range".