Respiratory physiology Dr. Martin Tobin testified Thursday that Floyd died from a "low level of oxygen" 1

A medical expert in the physiology of breathing ‘Dr. Martin Tobin’ said Thursday the way Floyd was restrained — handcuffed behind his back, face-down on the ground, with a knee on his neck — prevented him from breathing properly and caused his death.

Dr. Tobin, a prosecution witness also testified Thursday that Floyd died from a “low level of oxygen,” which caused damage to his brain and an abnormal heartbeat.

Another, a police surgeon, said Floyd didn’t overdose or have a heart attack.

A forensic toxicologist who analyzed George Floyd’s blood and urine told jurors Thursday the amount of meth in Floyd’s system was consistent with a prescribed dose – a “very low” amount.

The highly anticipated witness ‘Dr. Andrew Baker, the Hennepin County chief medical examiner,’ is expected to take the stand Friday, prosecutors said, ending the week-long of mostly medical testimony.

Last year, Dr. Baker ruled George Floyd’s death a homicide. He said Floyd’s heart and lungs stopped amid “law enforcement subdual, restraint and neck compression.”

The defense will argue that Floyd died as a result of the drugs in his system and underlying medical issues.