Discussions about policing must necessarily be largely about young men 15-30. Once you have noticed that, you can't unnotice it. Black athletes and entertainers get themselves involved in this cause which involves them and their friends more than their grandmothers, but white athletes and entertainers sign on very quickly as well, not only in support of black friends, but because they know they aren't far behind in police attention.
The flip side of that is that police training should disproportionately be about dealing with young men 15-30.
Additional fact: Young men in groups behave differently than young men individually.
Irony: Libertarians discuss policing as if it is mostly about police intrusion on adults over 30. Those are the things they get upset about. That is both true and untrue. The police don't spend much time on older adults unless they have to because of some obvious infraction, so one could say that libertarians are trying to artificially force issues they could do just fine going along with. On the other hand, they have a point that the police really shouldn't be much bothering with middle-aged and older people at all, because even if they are in technical violation they are usually not going to escalate into much trouble. That kind of policing is often for show.
Yes, there are exceptions, of public-endangerment or higher-level drug and criminal networks, just for starters. I waive the point.