Rabid Cop/Playing With

Basic Trope: A cop who is out of his mind.
 * Straight: Bob is a cop who brutalizes suspects, and sometimes shoots unarmed ones.
 * Exaggerated: Bob is more dangerous than the criminals he chases.
 * Justified: Bob knows the criminals are hiding critical information and resort to torture to obtain it.
 * Inverted: Bob is too light on crime, he lets criminals go free.
 * Subverted: Turns out Bob's Brutality was just propaganda by Criminals
 * Double Subverted: But they were right all along.