Medical expert says Floyd died from a lack of oxygen

A medical expert says George Floyd died from a lack of oxygen, which damaged his brain and caused his heart to stop.

Dr. Martin Tobin is a lung and critical care specialist from Chicago.

He testified Thursday at former Officer Derek Chauvin's murder trial that Floyd's breathing was too shallow to take in enough oxygen while he was pinned the facedown with his hands cuffed behind his back for 9 1/2 minutes.

Tobin says the pressure on Floyd's handcuffed hand, along with his neck and chest, made it difficult to expand his lungs.

His testimony came a day after a use-of-force expert said Chauvin had his knee on George Floyd's neck area the entire time that he pinned.