Amalgamate them all into one and ensure that single body has powers to act on crime and malfeasance.
While an investigation is under way, there is a need for secrecy, but when there are 'hearings' they need to be made public, and the public, as well as those under investigation, need to be aware that there are actions afoot.... that way some may be able to save themselves by falling on their sword.... or offering to make early restitution and also leave their public position ... and I don't mean just to the back benches....
Many such minor matters could be cleared up by the person under investigation 'entering an early plea' and then making restitution, for which their punishment could be discounted, except in severe cases, which must - in keeping with the Californian law that says anyone accused of murder must plead 'Not Guilty' - go to trial on facts.
Above a certain level of criminality - a trial MUST go forward, to protect the interests of the public and of the accused.