PCA (Proscribed Concentration of Alcohol) charges are rarely defended. There are a number of very good reasons for this fact. For one thing, in most cases there is no reasonable prospect of a successful defence. The system for the detection, documentation and prosecution of PCA offences is so finely tuned that there is often no room left for doubt about the guilt of the accused. Added to this is the cost associated with mounting a defence to a criminal charge. Even where there is a viable defence, some accused will choose to plead guilty to a PCA in order to avoid the substantial cost of a defended hearing.