Floyd wasn’t open and shut. In fact, the autopsy said the cops didn’t kill the dood. They did, however, neglect his medical crisis and should be held accountable for that, but they didn’t cause any physical harm to him.
You might benefit from more information.
https://meaninginhistory.blogspot.com/2020/06/the-truth-about-george-floyds-encounter.html
(The blog of a former US attorney)