Closing arguments are expected to begin on Monday.
Chauvin told Judge Peter Cahill that he would invoke his Fifth Amendment right against self-incrimination and would not take the witness stand.
Former police officer Derek Chauvin, on trial for the death of George Floyd, invoked his 5th Amendment right and will not testify.
"Is this your decision - not to testify?" the judge asked the former police officer, who was wearing a gray suit with a dark blue shirt and dark blue tie.More news: Ontario reports 4,362 new coronavirus infections and 34 deaths; hospitalizations surpass 2,000
Chauvin: "It is, Your Honor".
The Prosecution sought further testimony from the expert witness in rebuttal after another witness yesterday testified that carbon monoxide may have played a role in the death of Mr Floyd.
Those experts said the 46-year-old African American died of hypoxia, or a lack of oxygen, while being held facedown and handcuffed on the street with Chauvin's knee on his neck for more than nine minutes.
David Fowler, a retired forensic pathologist who testified for the defense on Wednesday, said Floyd died from cardiac arrest brought on by heart disease, drugs and other factors.
He said Floyd was held faceddown on the ground by Chauvin and other officers next to the exhaust pipe of a running police auto.More news: USA poised to sanction Russian Federation for cyber-attacks
In one final bit of testimony on Thursday, the prosecution briefly recalled a lung and critical care expert to knock down a defence witness' theory that carbon monoxide poisoning from a squad car's exhaust might have contributed to Mr Floyd's death.
Several police officers have testified that excessive force was used on Floyd and Minneapolis police chief Medaria Arradondo said Chauvin had violated the department's training policies and its "values".
Dr. Tobin, who is a pulmonary and critical care medicine physician and professor based at Loyola University Medical Center in IL, was educated at University College Dublin and did his residency through Trinity College Hospitals in Ireland.
Hill said Floyd had been "happy, normal, talking, alert" that day and then had fallen asleep in his vehicle. He had been detained outside a convenience store after being suspected of paying with a counterfeit bill.
The outcome of the high-profile trial is being closely watched after video of the arrest of Floyd captured by a bystander prompted widespread outrage, setting off protests over race and police brutality across the USA and around the world.More news: United States announces sanctions against Russian Federation and expels 10 diplomats
The most serious charge against the now-fired white officer, second-degree murder, carries up to 40 years in prison, though state guidelines call for about 12.