I am stupid, but who would handle sex crimes? Police or Sheriff or both? And of course we had a dioceses with sex crimes and who handles that? One day sex crimes will not be a crime, as long as the left gets their way; no laws.
Law enforcement is in charge of investigating sex crimes.
In the case of a diocese with sex crimes it is still the responsability of the law enforcement to investigate and prosecute. If the bishop has credible evidence of illegality the responsable thing to do is call the law enforcement and give up the evidence.
In the case of Sheriff Joe Arpaio the possibility of there being an investigation leading to a criminal prosecution would have been nil. That is how he 'protected' the people of Maricopa County.