Maybe we should be concerned right off the bat by transplanting military terminology (“civilians”?) into domestic police work, but of course that’s not the point.
The point is, such boards invariably turn out to be a joke, as subject to regulatory capture and the same incestuous and insidious corruption as most everything else.
When problems become as “systemic” as police misconduct apparently has, the solution, really, is independent lawyers and lawsuits; but the financial incentives have to be there for that to work. And they just aren’t.
It’s the same problem posed by the “financial” crisis, just a different context.