Were these cameras needed?

For years, my police department did not have internal cameras inside each precinct. We felt there was never a need, since the buidings were filled with armed police officers. So, why the change now? Cameras here, cameras there, cameras everywhere! Was officer and civillian employees safety the main concern or was this just a payback to some company for their political support? I would hope the cameras were installed for officer’s safety. Question: Should the world of surveillance cameras apply to the inside of police buildings? or, are most of these cameras a waste of taxpayers money?