The problem is actually that white policemen run roughshod over white, even those who are civil to them and otherwise orderly citizens. This has nothing to do with race,but with the human nature and the nature of the police. We don't need more police white or black. We need less.
People who become police officers are a representation or a cross section of society. How many times do we read, in the news, about bitter divorces of police officers or even domestic abuses. And even murder of a spouse. A policeman is simply a representation of the cross section of society. Except hired and employed to enforce the law. And they bring with them, all the social baggage to the job like anyone else at their jobs.
The solution isn't to reduce police officers, but to bring in people who are closer to the upper end of society (i.e., people who otherwise be doctors, teachers, social workers, etc.). Many times, a police officer is someone from the rank and file of a hardened blue collar workforce.
And if that is the case and since we can't always get people with a social conscious to become police officers, the next best thing is to continue to diversify the police force commensurate with the proportion of the population.