A variety of criminal actions can be taken against police officers.
Police informants usually initiate criminal actions. Private citizens can institute summary criminal actions; this is known as private prosecution.
Serious charges will not progress beyond the committal stage unless the Director of Public Prosecutions is prepared to take on the case. Criminal prosecutions against police officers, or anyone else, need to be proven beyond reasonable doubt.
If you bring a charge against a police officer and are unsuccessful, you will probably have to pay the police officer’s legal costs. Costs can be substantial, so think carefully before embarking on such an action.
You should seek legal advice before initiating private prosecution (see Legal services that can help).