I don't know if there is a study or theory to support this, but it seems that the longer any two opposing sides (like the police and criminals) face each other,

I don't know if there is a study or theory to support this, but it seems that the longer any two opposing sides (like the police and criminals) face each other, the stronger is the influence of one over the other. To a point when both sides have picked up significant good/bad behavior from each other. And then the very same police looks both aggressive and distasteful to the rest of us - i.e those who were not in the loop ever. Wait, quantum entanglement?