I found this video to be mildly disturbing. While there is no doubt that thousands of corrupt cops exist within the United States, the vast majority are at least mostly good. The reason we have this idea that police are evil is because the media feeds on tragedy as a means to generate money, and people also love something they can blindly throw support at. Police officers are trained to de-escalate situations as fast as possible, and when they shoot they always shoot to kill. Another reason people dislike the police force is because it is their job to enforce every stupid unethical law in the United States, and nobody likes being told what to do.
I'm all for a good conspiracy theory and calling out people when they do something stupid, but in this case if I had a gun drawn and was being charged at by a deranged man with a knife screaming shoot me, I would defend myself. Could this situation have been handled with no loss of life? Yes, of course. However, this is how the police are trained to handle these situations. Pro-tip, don't charge the police with a weapon (or anyone) if you don't want to die.