The crime of falsum is not defined by Roman legal writers, but it consisted of acts of fraud which were injurious to fides publica, such as forgery, counterfeiting money, and perverting the course of justice by fraud and perjury. The oldest legislative provisions at Rome against any acts of this description are those of the Twelve Tables, to the effect that a person who gave false testimony should be thrown from the Tarpeian [p. 659] Rock ( Gell.xxi. 53), and that a judge who took a bribe should be liable to capital punishment ( Gell.xxi. 7); but there were trials for false testimony before the enactment of the Twelve Tables (Livy, iii. 24Livy, 25Livy, 29; iv. 21). The next legislation in falsum, so far as is known, was contained in one of the Leges Corneliae passed in the time of the dictator Sulla , which was divided, according to Cicero, into two heads, the Lex Testamentaria and the Lex Numaria (Verr. ii. 1, 42), with reference to the two species of the crime the statute was directed against. Paulus, who gives its provisions, entitles it Lex Cornelia Testamentaria; it is also known by the more general title Lex Cornelia de Falsis.
The Lex Cornelia appears to have included only two specific kinds of falsum: (1) forgery and suppression of wills, and
(2) adulteration of the coinage.
An offence against either branch of this law was a crimen publicum, and was under the cognizance of a standing quaestio. The punishment of falsum under the law (at least when Paulus wrote) was deportatio in insulam (see Deportatio) for the honestiores, and the mines, crucifixion, or other degrading punishment for the humiliores. In place of deportatio in insulam the punishment, according to the statute itself, was probably the old form of banishment, known as ignis et aquae interdictio (q. v.). The property of a convicted person was confiscated.
The penalty of the Lex Cornelia was extended by piecemeal legislation to cases not comprised in the lex, but all of a similar kind. This supplementary law is sometimes referred in legal treatises to the Lex Cornelia, as if it had been an original part of that law. The instrument fabricated or falsified might be either public or private, as e. g. a rescript or edict of the emperor, an account book, or an instrument of sale.
Persons guilty of falsifying documents are called falsarii. As a precaution against such persons, it was enacted in the time of Nero that tabulae or written contracts should be pierced with holes and a triple thread passed through the holes, in addition to the signature ( Suet. Ner.c. 17; Paul.v. 25Paul., 6). In the time of Nero it was also provided that the first two parts (cerae) of a will should have only the testator's signature, and the remaining one those of the witnesses. Likewise, in order to prevent fraud, it was enacted under the emperor Claudius that a person who was employed by a testator to write a will should be liable to the penalty of the Lex Cornelia if he inscribed a legacy to himself, although he did so at the dictation of the testator (Cod. ix. 23, 3; Suetonius, Ner.17, attributes this law to Nero). The Lex de Falsis was further extended to fraudulent assumptions of names and rank, and to false pretences, as in the case of a contract to sell a thing to a person, when the vendor had already contracted to sell the same thing to some one else. The crimen falsi was also made to include perjury, the corruption of judges, and other kindred offences. By a senatusconsultum in the fourteenth year of Tiberius, the penalties of the law were extended to those who for money undertook to maintain causes, or to procure testimony; and by a senatusconsultum passed somewhat earlier, conspiracies for the ruin of innocent persons were comprised within the limits of the law.
According to Paulus (v. 25, 1), the refusal to accept in payment genuine coin stamped with the head of the princeps was on the same footing as the adulteration of the coinage, though in this case the element of fraud seems wanting. The use of false measures and weights was punished as falsum. It appears from numerous passages in the Roman writers that the crime of falsum in its different forms was very common, and especially in the case of wills. See Rein, Das Criminalrecht der Rmer, p. 774, etc.