To charge or not to charge - the question of when a person can be prosecuted

Today the wigs look at an important threshold question in the criminal justice system; what is the test or legal requirement for bringing a prosecution.  The issue has been highlighted recently in the ongoing ACT inquiry into the criminal justice system.  P.S Listeners can access Shane Drumgolds witness statement and evidence in full on the ACT inquiry website which is online.  In short, Mr. Drumgold says that section 26 of the Magistrates Court Act creates a test of mere suspicion for police to file a criminal charge and that subsequent to that - the DPP applies a reasonable prospect of conviction test.  He makes no mention in his statement of the reasonable and probable cause test.  The wigs note that an absence of reasonable and probable cause is part of the test for malicious prosecution in the ACT.  See ANDREI VATARESCU v THE COMMONWEALTH OF AUSTRALIA and THE AUSTRALIAN CAPITAL TERRITORY [2012] ACTSC 96 (15 June 2012).  The Wigs view is that section 26 is to be read subject to the common law and that when invoked by a police officer — reasonable and probable cause is required to charge.  Because charging begins the prosecution process.  In any event, it seems baffling that the DPP himself is unaware of the threshold at which a prosecution in the ACT becomes malicious.  See omnystudio.com/listener for privacy information.