This reminds me of Sandra Bland who was put into jail for three days because of improperly signaling a lane change. Police in the US is totally out of control it seems.
Most officers feel entitled to a considerable amount of respect and many of them are prone to use their discretion in order to extract revenge for perceived personal insults. This has always been the case. Recently we have technology that increasingly exposes this and other sorts of wrongdoing.
The difference is, today there's a bright spotlight on police brutality, and 200 million smart phones.
I certainly could be wrong, that's just my vague impression.
This may or not be true but we should reserve judgement I feel while the investigation is proceeding.
I know this is a generalization and that I should probably cite sources. But you are welcome to find discussion forums on your own.