While the importance of the comitia centuriata as a criminal court was enhanced by the lex Valeria Horatia and the Duillian plebiscite of 449, which prohibited the election of a magistrate with absolute jurisdiction, the number of officials competent to bring capital actions before this assembly was increased as a result of that law of the Twelve Tables which enacted that all resolutions concerning the caput of a Roman citizen should be offered to the centuries only.[1486] Thereafter the tribunes were required to prefer their capital accusations before this assembly, for the summoning of which they, like the quaestors and the duumviri perduellioni iudicandae, requested the auspices of a higher magistrate, ordinarily after 367 of a praetor.[1487] For a time, probably till the Hortensian legislation, they were dependent upon the patrician magistrates for this privilege.[1488] According to our sources the tribunes, with the approval of the consuls,[1489] entered upon their new sphere of judicial activity by bringing a capital charge against Appius Claudius and Sp. Oppius, past decemvirs, for misconduct in office, the specific charge being the abuse of justice in the interest of a person or of a party.[1490] The suicide of the accused prevented the trial. On the eight remaining decemvirs they passed in the same assembly a sentence of exile.[1491] M. Claudius, too, condemned for false testimony, was exiled, the death penalty being mitigated also in his case.[1492] The tribunes of 439 are said to have accused L. Minucius and C. Servilius Ahala for the part they had taken in the death of Sp. Maelius, and two years afterward Servilius was sentenced to exile by the comitia centuriata, to be recalled later by the same body. The charge against the former was false testimony, against the latter the putting to death of a citizen who had not been legally sentenced.[1493] Livy next mentions a charge, probably of perduellio, brought by the tribunes against Q. Fabius, 390, for having, in violation of the ius gentium, fought against the Gauls while he was an ambassador to them. He, too, is said to have died before the trial.[1494] All these cases are uncertain. If historical, they may represent the beginnings of capital jurisdiction of the tribunes, in rivalry with the duumviri; or they may in reality, like the case of M. Manlius, 384, already mentioned, have been duumviral. On either alternative they came before the centuriate comitia.