Thugs investigating themselves

In England, most complaints about the violence of thugs are investigated by the thug department itself. Those investigations generally conclude that the accused thug did not wrong. However, for cases that are reinvestigated independently, 40% of them lead to rejecting that conclusion and finding some degree of wrongdoing.

It seems to e that this calls for moving all such investigations outside of the thug department.

We see a similar problem in the US.