Is there racial disparity in our criminal justice system? I believe there is. For example, despite the fact that white and black people use drugs at similar rates, black people are jailed on drug charges 10 times more often than white people are. Black people are also three times more likely to be arrested for marijuana than white people are. So yes, there are racial disparity.
In life, We don't choose the environment where we are born but we have to choose to adapt and make the environment our benefit and some have better life privileges given than others. It's unlucky that some people are born in a world where opportunity is scarce. In areas where black people are arrested a lot more is unfortunately because its usually a notorious "bad" place. For example in the projects in major cities, for example, Cabrini Green was a massive project with almost a all black population and drugs and crime were high. Look, from personal experience my neighborhood has been relatively good and as a college student of course it's white where I am (Boulder). But the point is the reason why black people are a lot more arrest is because they're neighborhood is or has been a bad neighborhood with more than usual police presence