The United States has had its fair share of riots over the years, of which, those riots originate with those that are oppressed, disadvantaged, and treated unfairly, of which usually there is a seminal event, such as an assassination or the unjustified killing of a community member by the establishment's policing arm that sets it all off.
The obvious reason why it is never the rich or the elite that riot, is that when a given person or organization has everything, they are never going to riot or revolt, because they are living life at its very best; so then, unless everything of real importance that they have, is fundamentally under assault, they aren't ever going to riot or revolt, especially since, more times than not, they are the ruling class. As for the middle class, that are experiencing a distinct taste of what life should be, in which, they are usually pretty satisfied overall with their lot, and further seldom have the time or energy to revolt or riot, because they are very busy and occupied making a living, as well as being with family and friends, of which life overall is pretty good, so that, as long as that continues, they are basically content. As for the lower class or the underclass, as well as with those disaffected higher-education students, they are constantly going to be sitting on some sort of tinderbox, because not only do they basically have nothing, they often have no real opportunity to ever have anything of material worth, including their self-dignity and self-esteem. These people are discriminated against just for being disadvantaged, and essentially segregated from prosperous other peoples, as well as being consistently treated unjustly and unfairly, along with living within conditions that demonstrate in reality that they have no economic power or self-determination. So then, when the justice arm of the state, makes it their point, that these people in order to be controlled, must be dealt with by intimidation, incarceration, and harshness, then it is only a matter of time before riots will occur, time and time again.
The United States has made the cardinal error of believing that being tough on crime, makes for better citizens, and for a safer society. Ultimately, it never does, because it does not deal with the underlying issues that need to be addressed in a comprehensive fashion. That is to say, those having something of real value, and further those that believe that their future is hopeful, are typically not going to want to violently strike out and to thereby burn their own neighborhoods down. So then, when the police officers and the prosecutorial agents of the state, make it their principle, that they are going to work with the oppressed in treating them fairly, and demonstrate such in action by being a positive component of that society, along with providing real transparency to those people, then the conditions that help to foster violence, will invariably calm down.
There is a symbiotic relationship between oppression and riots, so that, the more the people are oppressed, the more riots there will be. If this country really wants lasting and meaningful domestic peace, it needs to provide those that are the most vulnerable and impoverished, with the tools and conditions that will provide them with real meaningful opportunity and change, for good citizens are created from governments that are good and fair to all of their people.