Derek Chauvin, the officer who killed George Floyd, had 18 complaints against him. But he was still on the job.

Sometimes, police chiefs know someone is a bad cop … but they still can’t fire the person.

One officer hit a woman at a parade. Another challenged arrestees to fights, several times. Police departments tried to fire those cops, only to be forced to hire them back after the officers’ unions sued.

Most of the police violence against protesters seen in recent weeks took place in places where cops have generous union contracts.

I interview Larry Cosme, head of America’s biggest law-enforcement association. He points out that cops have difficult and dangerous jobs. He argues that officers deserve union protections. Watch the video above for our debate.