Police in many municipalities are not fully funded via taxes. Instead their revenues are maintained via tickets, fines, and property seizures. There are recent cases that have gone to the supreme court related to some of these issues: https://newrepublic.com/article/148013/will-supreme-court-re..., I don't believe this case has been heard yet.
The point is, the police in the US have an economic necessity to pay their own salaries by fighting "crime". This incentivizes them in seizing property, prior to any conviction in court. Often the property is seized from people without the means to fight to get it back, and/or it's not worth the fight. This tactic of ticketing, fining and seizing property to pay for the police force, IMO, is the root cause of the issues between minorities and low income people and the police. In effect, the police need crime and will find crime, because they need to in order to earn their salaries.