Example: Police officers raid a [whatever] belonging to an organized crime syndicate. Some dude is standing by with a video camera as the officers carry the evidence to their cars. Two weeks later, every officer involved finds that his house has burned to the ground.
If you're going to send guys with guns around - assuming that they have the authority to use violence to conduct their jobs - and they're being paid out of my tax dollars, and claiming to be part of an organization that represents me; I damn sure expect to be able to monitor them.
Too bad. You can't give people guns and mace and handcuffs and a "legal right" to use force, and then say "you can't ask them to be accountable for their actions."
Banning accountability is a big step in the wrong direction.
They also get paid and they are not required to put their life at risk.