Derek Chauvin is obviously the tyrant in George Floyd's case - it isn't just the event, but he had been involved in previous cases of police brutality, just never as the cop who pulled the trigger (so to speak.) Still not as bad as Tony Timpa. If you want to see bad, look up Tony Timpa; if you've never heard of him, it's because he's white.

In the case of Rayshard Brooks, the tyrant is Paul Howard, Jr., the fucked-in-the-head DA who thinks that tasers are deadly weapons in police hands, but not when a resisting captures one and aims it at an officer's face. It's the other way around because police are trained in how to use tasers in ways that avoid permanent damage.

There is actually a Star Trek episode specifically made about the need to detect and root out tyrants in the system. It was a powerful and painful episode to watch because it starred sweet little old Jean Simmons as the tyrant, and her performance knocked it out of the park. She (well, her character) is starting to foam at the mouth as she loses it while Patrick Stewart apparently takes a break from Jean-Luc Picard to do a little Bill Barr. (Star Trek has come such a long way since that episode ...down into the crapper, that is.)