The gradual replacing of the layman with the expert in criminal proceedings can be seen in the transition from the 'Schwurgericht' (court sitting with a jury) to the 'Schoeffengericht' (court sitting with professional and lay judges) over the last century. Without changing its name, the 'Schwurgericht' had largely become a normal 'Schoeffengericht' of mixed composition. By 1974, 'Schwurgericht' cases were allocated to a permanent chamber of the Regional Court composed of three professional judges and two lay judges; the name was retained. Under the German principle of mandatory prosecution, the prosecuting authority must ex officio prosecute and prefer a charge against any person sufficiently suspected of having committed an act punishable and prosecutable under the law. While the state retains the right to institute criminal proceedings in order to punish violations of the law, some lesser offenses affecting personal attack, liability, or loss can be initiated by individuals but carried out by the public prosecutors. This differs from private prosecution because the injured party need only initiate prosecution. In making the principle of mandatory prosecution more concrete, the principle of equal treatment should be safeguarded by developing guidelines which would narrow the measure of discretion to the greatest extent possible.