Imagine this scenario:
Someone was shot dead by a police officer. Not much is known beyond the officer's claim that "the man acted delirious and ran towards me, so I shot in defense."
Who do you think instigated?
If you answered one way or the other, that is part of the problem.
We automatically assume the officer is in the right/wrong, but without a video recording no one could know for sure. We could imprison (not that the cop would be persecuted due to the corrupt system) the wrong person.
Cops wearing a body cam can only HELP them!
After all, what are they afraid of? If you are a "good cop", you shouldn't care.
Police officers should wear body cameras because it is safer for them. We need police officers to be safe. Police officers can catch thiefs. Then the thiefs will be put in jail. Cops can contact people other cops more easy. Cops can show other cops people's drivers license and stuff like that.