You folks answering, if you were paying attention to the trial, you would know by now that it was the pressure on his ribs that killed him, not on his neck. Unless it was heart disease and carbon monoxide.
I saw the famous picture of the knee on the neck, and I know my physiology; so I couldn't see how that could have killed him. Turns out it didn't. It was the knees on his back and the pressure pushing his handcuffed hands into his ribs so he couldn't inhale enough, until finally he ran out of oxygen.
Drugs might have contributed, but it looks like they didn't; unless some more evidence comes in on that.
Sorry for the rant, My Clone. It really isn't clear yet why the police responded the way they did: accident, mistake, desire to kill, desire to hurt, fear of Floyd, fear of the onlookers, ignorance - I'm watching the trial and I don't know yet.
This is very different from Zimmerman's trial, in which the Prosecution proved reasonable doubt well before the Defense had its say.