It’s in the last minute and a half of this video that the doctor testifying in Chauvin’s defense provides what I consider the most damning evidence for the prosecution. It relates to the difference between the last two videos in my earlier post where, in the color negative version of the Floyd incident, the person who died was immediately placed in a recovery position and subjected to CPR.
It is never possible to really prove the intended outcome of an action, so I guess the legal definition of murder is generally more along the lines of an intended act (or omission?) whose consequence is known to almost certainly be death. In Chauvin’s case we can be reasonably certain that he knew of the possible risk of knee-on-neck restraint, but in my opinion it is not obvious that while Floyd was complaining Chauvin had any good reason to know that what he was doing was almost certain to cause death(*); and since it is often used by police, taking that level of risk is at least sometimes considered not to be murderous even if death does ensue.
But I think we can be almost certain (eg from senior police testimony) that Chauvin knew from his training at least that when Floyd stopped complaining, cardiac arrest was likely to have occurred (albeit very likely largely due to the drugs and panic as much or more than actual airway obstruction). And from that moment on, any interference with prompt attempts at resuscitation does amount to murder.
*- Perhaps it should be more widely known by police that knee-on-neck restraint is very likely to cause death when applied to people in a state of drug-induced panic – to the extent that using it at all in such cases should be prohibited, and should result in an almost automatic conviction for at least manslaughter if death does ensue.