Most of the examples were about police targeting black people disproportionately compared to other races concluding that is because of systemic racism. Is there a law that compels police officers to behave in such a way? The answer is none. Therefore it can't be systemic. The targeting comes from individual decisions by individual officers. Whether this is from prejudice or bad experience or plain racism is unknown. For that you would have to divide individuals officers into buckets by their race in see the statics for each bucket. For example do black officers also arrest disproportionate number of black people? You would need all the combinations from different buckets to get a sense of underlying reasons.