If that's true, it suggests the racism problem is more serious than we thought; that police of all colors may be endemically racist as a group; that it's not just mainly white police.
That said, we don't see black-on-black murders of innocent people so much. This might be due the symbolism of white-on-black murders in broad daylight with onlookers. Or it might not. Regardless, it's all racism if innocent black folks are getting murdered more often.
Really? The murder rate inside the black community is massively higher than within any other community in America. Also black people murder more white people than vice versa. If you take account of the different community sizes the disparity becomes even more extreme. If this is coming as news to you I don't know where you've been all your life.
What I meant to write was we don't see black-on-black police murders of innocent people hitting the big news and causing mass demonstations so much.
My 'aetiology', I think it comes down to less opportunities. Without discipline that comes from a stable environment, motivation can easily turn to violence and crime. This leads to difference in police behavior. I have nothing to back this up and I don't know how to 'cure' this.
To bring this back to the start: All I want to say is that the protests are not that bizarre. America is the cultural center of the West, people are as informed about this incident as they are about their local news. Many don't want to live in a racist future, even more so for their children. So they risk the lives of their parents to improve the lives of their children.
Was this a death caused by racism? I don't know. It appears to be. Thus the protests.
Black and Hispanic police are as likely or more likely to kill people of color as white officers
https://www.citylab.com/equity/2019/08/police-officer-shooti...
With regard to your second point, you're hinting at something, why don't you spell out your aetiology for the high levels of crime along black people along with your evidence for that causation.