The more I think about this the more I think it was Joey Gallo. But that being said, it's not totally impossible it was the FBI. Unlikely, but not impossible. Law enforcement doesn't like "uppity" ethnic types who demand their rights. It's not likely though, because most people who die in the custody of law enforcement are shot while pulled over, or die in jail of asphyxiation that is ruled suicide. No need to take him out in front of so many witnesses. So most likely Gallo, or maybe the other bosses just got tired of his civil rights act. Whoever did it knew Joey Gallo was most likely going to be blamed.