I see a few flaws in your argument.
1. Death statistics likely do not represent the entire problem, but rather the tip of the iceberg. Deaths/murders are rare overall, but hard to hide.
2. Your 0.0006% is calculated in a way to give one of the smallest possible magnitudes, and doesn't really offer any useful comparison. You can do similar to minimize any issue. If you wanted to make an argument against there being a systemic issue here, you really ought to compare per-capita black deaths-by-police to per-capita white deaths-by police or something. This paper [1] (first result of my Google search) give such a comparison and states:
> The highest levels of inequality in mortality risk [from police use of force] are experienced by black men. Black men are about 2.5 times more likely to be killed by police over the life course than are white men. Black women are about 1.4 times more likely to be killed by police than are white women.