That's a bad idea. A lot of policing is taking someone aside an giving them a warning, defusing a situation between angry people, etc... A camera only complicates these matters.

What might be a better idea is stripping them of their privileged position. Today, if a police officer says something in court, it is automatically the truth. Take that away from the police, and let the camera be the official truth teller. Give accused people automatically a full version, so prosecutors can't edit against them.

UPDATE whoops, this should be attached to the grandparent post.