as far as i can tell, what happened in minneapolis was a very stupid police officer. there's a lot of people with a lot of agendas, but the constant that keeps coming up in these cases is that police officers nowadays are, more often than not, of exceedingly low intelligence. there's not really another way to explain what happened.
the thing is that it isn't an accident - the police training specifically pulls out officers that are obedient, and specifically removes officers that demonstrate any sort of independent thinking.
so, the most frustrating thing you're going to hear about this is how he was a "bad apple", and how he "failed" to "protect". that's all rooted in utter nonsense. he's exactly what he was created to be, and he did exactly what he was trained to do.
everything else aside, you'd have to be halfway to being retarded to keep your knee on somebody when they're yelling at you like that.
and, while other scenarios may lead to other recommendations, the basic truth here is that this officer was obviously simply not intelligent enough to do his job.
if we must have cops, we need to stop making them so fucking stupid.