Derek Chauvin, the officer who killed George Floyd — thereby triggering months of racial strife and calls to defund the police — had 18 previous complaints filed against him. Why was he still on the police force with that pattern of behavior? Because police unions protect their own, regardless. John Stossel explains how police unions are the root cause of bad cops, and shares an example of a large US metro that got rid of its police union — and cut crime and costs.