George Floyd died of a lack of oxygen from being pinned face down on the pavement with his hands cuffed behind him, a medical expert testified at former officer Derek Chauvin's murder trial.Mr Floyd's breathing while he was being held down by Chauvin and other officers was too shallow to take in enough oxygen, which in turn damaged his brain and caused an abnormal heart rhythm that made his heart stop, said Dr Martin Tobin, a lung and critical care specialist at the Edward Hines, Jr VA Hospital and Loyola University's medical school in Chicago.
