In relation to the video - the man is clearly resisting. Whether this warrants 5 cops to step on him and pin him to the pavement is debatable, but he continues to resist throughout the video.

I would like to address the 'police targeting minorities issue' if you would allow me - many police officers lack intelligence and self-awareness, but not all. But according to the State, this kind of person is the most efficient kind of enforcer. No time for thinking or reflecting; just acting. The police are trained this way. Importantly, doing so aggressively (acting) ensures that fear/intimidation is instilled in people and dissuades those from considering breaking a law (but not all).

Now in regard to the systemic issue of police on minority targeting: The sad fact is that there are more minorities living in poverty than non-minorities. The reasons why that is the case are debatable -- but we won't get into that here. The gist, however, is that those living in poverty are more likely to break laws. This is not an opinion. This is a fact. Whether it be lack of parenting, improper value training, lower empathy in these areas - what ever the case (also debatable), poverty stricken borne people are more prone to drug use, violence, harassment, abuse, etc as a conditioning of their environment.

With that said, the police execute on bias. More times out of total in confrontation with a minority, they are confronted with violent resistance. They compensate by being extra aggressive, extra stern, and generally excessive with use of force when confronting a minority. We are all prone to bias, even the police. The police are people. In future confrontations they subconsciously execute on the basis that based on previous encounters with minorities, more times out of total they were received with violent resistance. And if not they themselves, personally experienced this, they integrate stories and scenarios told from their partners and colleagues into their bias.

tl;dr The police use excessive force and exact scrutiny on minorities based on basic psychological flaws of the human psyche.