Key Moments on Day 9 of the Derek Chauvin Trial

A pulmonologist testified that George Floyd died “from a low level of oxygen,” and that being handcuffed and having knees on his neck and back contributed to his shallow breathing.

The trial of the former officer Derek Chauvin will continue on Thursday after a day of testimony focused on Mr. Floyd’s drug use on the day of his death. Mr. Chauvin’s defense has tried to argue that Mr. Floyd died from a possible overdose, but the prosecution blames the actions of Mr. Chauvin, who pinned Mr. Floyd with his knee for about nine and a half minutes. Here are some key takeaways from recent testimony. A veteran lung doctor testified on Thursday that George Floyd’s death was caused in part by Derek Chauvin’s knees pressing against his neck and back, making it impossible for him to breathe, and that Mr. Floyd showed signs of a brain injury about four minutes before Mr. Chauvin lifted his knee from his neck.