So you're claiming that there is no way in which the US police and justice systems treat black people differently that isn't reducible to intelligence or conscientiousness differences?

More or less. Remember lower conscientiousness translates into higher propensity to commit violent crime.

There's also a certain amount of what may fairly be called "black privilege" due to the fact that in any highly publicized crime, or alleged crime, with white defendants and a black victim there will be social pressure to through the book at them regardless of lack of evidence, or mitigating circumstances like the victim beating the defendant's head on the pavement. And conversely if the defendants are black and the victim is white there will be social pressure to go light on the defendants some people even arguing that the victim brought the crime upon himself due to his racism. Something similar happens with police shootings. Shootings of blacks are more likely to make the national news and the victim described as an angelic youth even if he had just robbed a convince store and was charging for the officer's gun when he was shot.