The ædiles are found in Roman history exercising functions of criminal jurisdiction, although their general powers were confined to the special duties of caring for the games, the market, and the archives.

But the criminal jurisdiction of the magistrates who replaced the king at the downfall of the monarchy was abridged and almost destroyed by the famous lex Valeria (de provocatione). This law was proposed 509 B.C. by Publius Valerius, one of the first consuls of Rome, and provided that no magistrate should have power to execute a sentence of death against a Roman citizen who had appealed to the judgment of the people in their public assembly. This lex was the magna charta of the Romans and was justly regarded by them as the great palladium of their civil liberty. And it was this law that inaugurated the popular jurisdiction of the comitia. The result was that for more than three hundred years the final determination of the question of life or death was in the hands of the people themselves. From the passage of the Valerian law the function of the magistrates was limited to the duty of convincing the people of the guilt of an alleged criminal against whom they themselves had already pronounced a preliminary sentence. The magistrates were, therefore, not so much judges as prosecutors; the people were the final judges in the case.

Mode of Trial in the Comitia, or Public Assembly.—On a certain day, the prosecuting magistrate, who had himself pronounced the preliminary sentence against an accused person who had appealed to the people in their public assembly, mounted the rostra, and called the people together by the voice of a herald. He then made a proclamation that on a certain day he would bring an accusation against a certain person upon a given charge. At the same time, he called upon this person to come forward and hear the charges against him. The defendant then presented himself, listened to the accusation, and immediately furnished bond for his appearance, or in default of bail, was thrown into prison. Upon the day announced at the opening of the trial, the prosecuting magistrate again mounted the rostra, and summoned the accused by a herald, if he was at large, or had him brought forth if he was in prison. The prosecutor then produced evidence, oral and documentary, against the prisoner. The indictment had to be in writing, and was published on three market days in the Forum. The prosecution came to an end on the third day, and the accused then began his defense by mounting the rostra with his patron and presenting evidence in his own behalf. The prosecutor then announced that on a certain day he would ask the people to render judgment by their votes. In the early years of the republic, the people voted by shouting their approval or disapproval of the charges made; but later a tablet bearing one of the two letters V. (uti rogas) or A. (absolvo) was used as a ballot.

The effect of popular jurisdiction in criminal processes at Rome was in the nature of a two-edged sword that cut both ways. It was beneficial in the limitations it imposed upon the conduct of single magistrates who were too often capricious and despotic. But this benefit was purchased at the price of a kind of popular despotism not less dangerous in its way. It has always been characteristic of popular assemblies that their decisions have been more the outcome of passion and prejudice than the result of calm wisdom and absolute justice. The trouble at Rome was that the people were both legislators and judges in their public assemblies; and it nearly always happened that the lawmakers rose above and trampled upon the very laws which they themselves had made. The natural offspring of this state of things is either anarchy or despotism; and it was only the marvelous vitality of the Roman Commonwealth that enabled it to survive.

The reports of the great criminal trials before the comitia reveal the inherent weakness of a system of popular jurisdiction in criminal matters. Personal and political considerations foreign to the merits of the case were allowed to take the place of competent evidence; and issues of right and expediency were too frequently mixed up. The accused, at times, trusted not so much in the righteousness of his cause as in the feelings of compassion and prejudice that moved the people as popular judges. And to excite these feelings the most ludicrous and undignified steps were sometimes taken. The defendant nearly always appeared at the trial in mourning garb, frequently let his hair and beard grow long, and often exhibited the scars and wounds received in battle whilst fighting for his country. He sometimes offered prayers to the immortal gods and wept bitterly; at other times he caused his children and other relatives to appear at the trial, wailing, and tearing their clothes. Not content with presenting all the pathetic features of his own life, he left nothing undone to expose his opponents to hatred and contempt. It thus happened that many of the great criminal causes of Rome were mere farcical proceedings. A few instances may be cited.

Horatius, though tried in the time of the third Roman king, was pardoned by the people for the murder of his sister because of his heroic deed in single combat with the three Curiatii, and because his father had lost three children in the service of the state.

In the year 98, Manlius Aquillius, the pacificator of Sicily, was tried for embezzlement. Marcus Antonius, his advocate, ended his argument for the defense by tearing the tunic of Aquillius to show the breast of the veteran warrior covered with scars. The people were moved to tears and Aquillius was acquitted, although the evidence was very clear against him.

In the trial of M. Manlius, 384 B.C., new tactics were employed. The accused refused to appear in mourning. There was no weeping in his behalf. On the other hand, Manlius relied upon his services to the state for acquittal. He brought forward four hundred citizens who by his generosity he had saved from bondage for debt; he exhibited the spoils taken from thirty slain enemies, also military decorations received for bravery in battle—among them two mural and eight civic crowns; he then produced many citizens rescued by him from the hands of the enemy; he then bared his breast and exhibited the scars received by him in war; and, lastly, turning toward the Capitol, he implored Jupiter to protect him, and to infuse, at this moment, into the Roman people, his judges, the same spirit of courage and patriotism that had given him strength to save the city of Rome and his whole country from the hands of the Gauls. He begged the people to keep their eyes fixed on the Capitol while they were pronouncing sentence against him to whom they owed life and liberty. It is said that his prosecutors despaired of convicting him amidst such surroundings, and adjourned the trial to another place, where the Capitol could not be seen; and that thereupon the conviction of Manlius was secured and his condemnation pronounced.

In the year 185 B.C., the tribune M. Nævius, at the instigation of Cato, accused Scipio Africanus before the tribes of having been bribed to secure a dishonorable peace. It was clearly evident that a charge of this kind could not well be sustained by evidence; but it was believed that a conviction could be secured by an appeal to the passion and prejudice of the multitude. But this advantage operated as greatly in favor of Scipio as it did in favor of his accusers. And he did not fail to use the advantage to the fullest extent. In seeming imitation of M. Manlius, two hundred years before, he appealed for acquittal to the people on account of his public services. He refused to appear in mourning, offered no evidence in his own behalf, nor did he exhibit the usual humility of an accused Roman before his countrymen. With proud disdain, he spurned the unworthy imputation of bribery, and pointed the people to the magnificent achievements of his brilliant public career. He reminded them that the day of the trial was itself the anniversary of his victory over the greatest enemy that Rome ever had, at Zama. It was degrading, he exclaimed, both to him and to the Roman nation, to bring such a charge on this day against the man to whom it was due that the Commonwealth of Rome still existed. He refused to lower himself, he said, by listening to the insolent charges of a vulgar brawler who had never done anything for the state. He declared that instead he would repair at once to the temple of Jupiter and render thanks for his victory over Hannibal to the protecting gods of his country. With these words, he left the Forum and went to the Capitol and from there to his house, accompanied by the great majority of the people, while the accusing tribune and his official staff were left alone in the market place.

The inevitable result of these cases of miscarriage of justice, in which patriotic bravado and rhetorical claptrap took the place of legal rules, was a desire and demand for the reform of criminal procedure. Besides, it had ever been found troublesome and inconvenient to summon the whole body of the Roman people to try ordinary offenses. It was only in cases of great gravity that the ponderous machinery of the comitia centuriata could be set in motion. This difficulty was increased with the growth of the republic, in which crimes also grew in number and magnitude. The necessity for the reform of the criminal law resulted in the institution of permanent tribunals (quæstiones perpetuæ). A series of legal enactments accomplished this result. The earliest law that created a permanent quæstio was the lex Calpurnia of 149 B.C. And it was the proceedings in these courts, which we shall now describe, that should have guided Pilate in the trial of Jesus.