Officer Derek Chauvin didn't kill George Floyd over race - he killed him because he hated his guts. If you assume those two didn't know each other, check the facts in more detail. Both worked as bouncers, and George Floyd was great at his job - de-escalating conflicts, and keeping things calm. The bad cop, Derek Chauvin, was the opposite - a hothead bouncer who created trouble where it wasn't needed. (Police officers get paid poorly, so they take second jobs). Chauvin was fired from that job because of George Floyd's complaints about him - Chauvin hated Floyd's guts.
I speculate in the back of that police car, where nobody could hear, Chauvin whispered "I'm going to fvcking kill you", after which George Floyd started struggling. In my view, there was nothing unintentional about kneeling on Floyd's neck - it was murder one, intentional homicide planned before the fact (when Chauvin was driving to the scene, hearing Floyd's name).
You could still say the assumption that Chauvin could kill Floyd and get away with it was racist... but George Floyd was not killed because of his race. He was killed because Derek Chauvin hated his guts.