Ok, we all say what we would do if we could determine the bad guy and the good guy. Say you are in a rougher area of town, and you see a group of guys beating a man and a woman. You pull up and notice that their cars all happen to have lights in the dash and back glass, and several of the men beating the couple are wearing badges and vests that identify them as police. You see a marked unit on scene and a uniformed officer also participating in the beating. This is obviously not a pair of resisting criminals and is just two people getting a beat down and getting beaten to a pulp by a gang of dirty cops, what do you do?