Nothing can be more clear than the duty of the Commonwealth to prove the identity of the offence charged in a complaint or indictment, with that on which it seeks to convict the party charged before the jury of trials. The fundamental principles of our government require this as an essential safeguard to the rights and liberty of the citizen. If it were not so, the constitutional privilege of a party, before he is held to answer to an offence, to have it “fully and plainly, substantially and formally described to him,” and to be secure from arrest until “ the cause or foundation of the warrant be previously supported ny oath or affirmation,” might be violated at the pleasure of prosecutors. Such a practice would be also in direct contravention of § 3 of the Rev. Sts. c. 135, which requires that when a complaint shall be made to a magistrate that a criminal offence has been committed, he shall examine the complainant under oath ; and if it appear that such offence has been committed, he shall issue his warrant, reciting the substance of the accusation. These provisions of our constitution and of the statute are but a declaration and affirmation of the ancient rule of the common *33law, that no one shall be held to answer to an indictment or information unless the crime with which it is intended to charge him is set forth with precision and fulness. Petition of Right, 3 Car. 1, § 5. Regina v. St. George, 9 Car. & P. 491. Commonwealth v. Phillips, 16 Pick. 213. So strictly is this held, that if an indictment charges a party with committing an offence upon the body or property of a person unknown, and it is made to appear at the trial that the name of the person was in fact known to the grand jury at the time when the indictment was found, the defendant will be entitled to an acquittal. The offence must not only be proved as charged, but it must be charged as proved. Archb. Crim. Pl. (5th Amer. ed.) 36. 1 Chit. Crim. Law, 213. 2 East P. C. 651, 781. Rex v. Walker, 3 Campb. 264. Rex v. Robinson, Holt N. P. 595.
But there is another view of the present case, which is equally decisive, and leads to the same result. This was the trial of an appeal from the judgment of a justice of the peace. The object of an appeal is to revise the judgment of an inferior court before the appellate tribunal. But this cannot be done unless the same offence is there tried which was proved and passed upon by the court below. Besides; if the government can, on the trial of an appeal, be permitted to abandon the original offence charged, and on which the accused party was tried before the magistrate, and substitute another and distinct offence in its place, and support it by proof, it is obvious that the right of appeal, which was intended solely as a benefit and privilege to the party charged, might often be converted into a burden and a snare.
Exceptions sustained.