I want one example of any public school, company or corporation, any police department, anything anywhere that has a written policy that would be considered oppression due to race, sex, anything. These type policies did in fact exist through the 1960's, which to El OchoCinos point is abominable in and of itself, but that is not the case today.
The fact that some racism can run through a single department is not oppression, it's a problem which needs to be seriously addressed, but it is not oppression, especially given the fact that the police departments in question are multi racial top to bottom.