Well, those guys/gals chose to become cops; knowing it was a risky career. That is all completely orthogonal to the point that public servants must be held accountable to their employer - the public. Police even more so, since "society" gives them something that - in essence - NO one else is given... a monopoly on the "legal" use of force.
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.
