Oh that’s real easy, because these two groups of people have drastically different ideas about what law enforcement is for and what it does.
Most white Americans view cops as heroes while most blacks view them as anti-heroes, and there is evidence (plenty actually) to support both perspectives.
The issue is very complex, but I know from experience a typical urban police department (say Cleveland Ohio where I grew up) is replete with thugs, cons, and criminals with badges, who prey on the poor, the weak, the minorities. A typical suburban police department (say Prince Williams County where I currently live) is extremely professional, usually honest, and pretty effective at keeping the peace within the community; and yet this department still has its fair share of problematic cops who do a total 180 with all that training and professionalism when dealing with the poor, the weak, the minorities etc. If these two groups of people have entirely different experiences with law enforcement, then of course they will react differently to the shooting. White people will typically bend over backwards to give police the benefit of the doubt even, (or probably especially) when they are blatantly killing black people unnecessarily. Yes police kill whites, and in higher numbers, than blacks. But police also DON’T kill a lot of whites that behave really, really, really badly. Whites that march around with guns screaming about “open carry” and get indignant when questioned about their erratic behavior by police. They get coddled…they don’t get shot. Why don’t blacks EVER and I mean EVER get that same sort of treatment?
The problems are systemic. But after years of police oppression of minorities in urban environments the breaking point has been reached, and the responses we see now have literally been building for decades. Anger and frustration about the drastic differences in treatment minorities receive from police have been building for decades. The situation is at a breaking point now, and no there are no easy answers.