It's also called felony murder. To prove this count, prosecutors had to show that Chauvin killed Floyd while committing or trying to commit a felony — in this case, third-degree assault. They didn't have to prove Chauvin intended to kill Floyd, only that he intended to apply unlawful force that caused bodily harm.
Prosecutors called several medical experts who testified that Floyd died from a lack of oxygen because of the way he was restrained. A use of force expert also said it was unreasonable to hold Floyd in the prone position for 9 minutes, 29 seconds, handcuffed and face-down.
Defense attorney Eric Nelson tried to raise doubts about Floyd's cause of death — saying underlying heart issues and drug use were to blame. He also argued that Chauvin's actions were reasonable, saying Floyd was big, under the influence of something, could start fighting and that nearby bystanders presented a threat.

