They are arrested for violent crime at a disproportionate rate, that doesn't mean they commit violent crime disproportionately. Predictive policing measures tend to target blacks disproportionately, and blacks tend to be more often falsely accused, wrongfully convicted and handed worse sentences than whites for the same crime. This has always been the case in our criminal system. After slavery, blacks quickly filled up the jails and prisons, and it was all because their existence was criminalized, to bring back forced labor. White people even disguised themselves as blacks when committing crimes.
Rather than recognizing evident racism in our criminal justice system, you would rather hold a racist belief that blacks are simply more criminal.