The aediles are sometimes found exercising functions of criminal jurisdiction, all of which cannot be brought into close connexion with any of their special powers, and which, therefore, do not spring from the ordinary _coercitio_. This criminal jurisdiction was, like the civil jurisdiction of the curule aediles, an anomaly, for these magistrates did not possess the _imperium_. It is to be explained partly as a survival (for some jurisdiction of the kind had been exercised by the plebeian aediles) and partly as the result of considerations of convenience. Before the institution of the _quaestiones perpetuae_ there was a great lack of criminal courts at Rome. The _quaestores_ were at hand for the trial of grave capital crimes against individuals, and the tribunes for political jurisdiction. What was needed was a magistracy for bringing ordinary and lesser crimes involving a money penalty (_multa_) before the people, and this was found in the aedileship. It is true that the aediles were not prohibited from undertaking the prosecution of political crimes that might be met by a fine, such as a mild case of _majestas_[974] or the bribery of a bench of _judices_;[975] and judgment on a breach of the peace (_vis_) was in harmony with their police duties.[976] But as a rule it is a class of ordinary crimes, somewhat beneath the dignity of tribunician prosecution, that we find them visiting. Such were adultery committed either by men or women,[977] usury,[978] illegal speculations in corn,[979] and the offence of exceeding the amount of domain-land which the laws permitted an individual to possess.[980] The aediles were stimulated to a career of prosecution by the singular custom which permitted them to retain the fines collected and to apply them to any public purpose which they pleased. We find them expended on buildings and adornments of the city, and by the plebeian aediles on their games.[981] _The Quaestors_ We have already spoken of the criminal investigators (_quaestores parricidii_), whom tradition attributes to the monarchy,[982] and of the more certain assistants of the consuls for criminal jurisdiction and finance (_quaestores parricidii et aerarii_), who are assigned to the early Republic.[983] We have seen that, first nominated by the consuls, they were soon elected by the tribes,[984] and we have witnessed the opening of the office to Plebeians when, in 421 B.C., the number of quaestors was raised from two to four, and one of these officials was assigned to each consul in the field.[985] About the year 267 B.C. four more were added for the purposes of Italian administration, and no further change is recorded until Sulla raised their number to twenty,[986] although some intermediate increase is not improbable.