In an action for a malicious prosecution against one, in the name of the Commonwealth, the averment on the *202part of the plaintiff, that the complaint was made without reasonable cause, lies at the foundation of the suit; and although it is in form a negative proposition, it is incumbent on the plaintiff to establish it by satisfactory proof. This kind of suit, by which the complainant in a criminal prosecution is made liable to an action for damages, at the suit of the person complained of, is not to be favored; it has a tendency to deter men who know of breaches of the law, from prosecuting offenders, thereby endangering the order and peace of the community. Absence of probable cause is essential; from want of probable cause, malice may be inferred ; but from malice, even if express, want of probable cause cannot be inferred.
An ultimate acquittal, of the offence charged, though necessary to be proved, is but a short step towards the maintenance of an action for malicious prosecution. Malice, and absence of any reasonable and probable cause, must also concur with an acquittal.
In the present case, the prosecution complained of was a complaint before a justice of the peace by whom the plaintiff was convicted; from this judgment he appealed, and on trial in the court of common pleas was acquitted.
On the trial, it appeared from the pleadings and evidence, and was admitted, that the complaint was for an offence which the magistrate had, by law, jurisdiction to hear, decide and render a judgment in ; also, that neither in the trial before the magistrate, nor in the trial in the common pleas, was the defendant a witness. On this case, the court ruled that such a conviction was proof of probable cause; or, to state the proposition with more precision, it negatived the plaintiff’s leading and essential averment that the complaint was made without reasonable and probable cause, and that, for this reason, the action could not be maintained, and thereupon ordered a nonsuit.
The court are of opinion that this direction was right. The question of reasonable and probable cause, when the facts are not contested, is a question of law. And when the plaintiff had been convicted by a tribunal, constituted by law, with authority to render a judgment, which, if not appealed from, would have *203been conclusive of his guilt, and such judgment is not impeached on the ground of fraud, conspiracy or subornation in its procurement, although afterwards reversed on another trial, it constitutes sufficient proof that the prosecution was not groundless, and to defeat an action for malicious prosecution. The case of Whitney v. Peckham, 15 Mass. 243, is directly in point, and we think it is well sustained by authorities.
It is said that the question of probable cause is a mixed question of law and fact, and that the facts should have been left to the jury. Here no fact material to the question was controverted, and then there was nothing to leave to a jury.
Exceptions overruled.