This was an action to recover damages as compensation for injuries sustained from an assault on the plaintiff alleged to have been committed by the defendants.

The case was given to the jury upon evidence tending to show that the alleged assault had been committed under the following circumstances: Defendant Gibbon and the mother of the plaintiff were owners of adjacent parcels of land in the city of San Francisco. There was a dispute between them as to the true division line of the lots. Gibbon had constructed near to what he believed to be the line a shed about ten feet high, the roof of which, according to the assertion of the plaintiff, projected over a part of his mother’s lot and came near to her house. Notice of the projection was given to the defendant, but he gave no heed to it. In that state of the question, the plaintiff on the 25th of September, 1876, took several men on to his mother’s lot to saw off that part of the roof of the shed which extended over so much of his mother’s lot as lay between her house and the supposed dividing line, and to move her house close up to that line. One of the men had mounted the roof of the shed and was in the act of sawing off the projection when the defendant, Quinlan, appeared on the balcony of the house on Gibbon’s lot armed with *389 a double-barreled shotgun, which Gibbon had loaded with powder and buckshot, and put in the hands of Quinlan, “ to watch his property against the Dinans.” To prevent Quinlan from using the gun against the person on the shed, the plaintiff and another caught hold of the gun and a contest resulted between the parties, in which the gun in the hands of Quinlan was discharged into the body of the plaintiff, severely wounding him.

On submitting the case to the jury, the court, among other things, instructed them as follows:—

“1. You are instructed that the controversy over this piece of land did not justify the use of fire-arms in its settlement; that a person has no right to use deadly weapons excepting it be in the defense of life or in the protection of his domicile. Those are the only cases in which a party is authorized under the laws of this State to use anything which is calculated to produce death.

“ 2. If you believe from the evidence that the defendant did use this weapon for the purpose of this transaction—for the purpose of producing great bodily injury—if he used it, in fact, at all, to resist the encroachment even of the plaintiff in this action, then it is your duty, under the law, to find a verdict against him for the actual damages which the plaintiff sustained, whether there was malice in it or not.

“3. The very fact that the defendant used this unlawful weapon gives the plaintiff the right to recover.”

Of course, if the evidence showed that the defendant only used the weapon for the deliberate purpose of producing great bodily injury on the plaintiff, it would have been the duty of the jury to find for the plaintiff. The use of a deadly weapon for such a purpose would render a party not only civilly but criminally liable. No one is justifiable in law, even under a pretense of right, to inflict on another a wanton and malicious assault. But if the defendant used the weapon “to resist the encroachment of the plaintiff” as a trespasser on his premises, such use would not be unlawful, unless it was unnecessary. For there is no doubt that a person in the lawful possession of premises has a right to protect them or to eject an intruder upon them; and in the exercise of his right, for that purpose, he may use such force as may be reasonably necessary. Acting within the limits of a *390 reasonable use of force to protect himself or his property he is justifiable in law; but if he exceeds the force necessary he becomes a trespasser ab initia. Yet the necessity of the force which was resorted to, to repel the “ encroachment ” of the plaintiff upon the defendants’ premises, and the question whether the defendants used more force and violence upon the person of the plaintiff than was necessary for the protection of their property, should have been left to the jury. It was interfering with their constitutional right to determine all matters of fact, for the court to instruct them that the mere use of the Aveapon to resist the encroachment of the plaintiff gave him the right to recover.

Besides, if the plaintiff Avas the aggressor, and had actually employed others to destroy what Avas confessedly the property of the defendant, and Avas aiding and abetting them in such attempt to destroy it, in the performance of which he received his injuries, these circumstances were proper for the consideration of the jury in mitigation of damages, although they may not lurve been sufficient to justify the defendants for the use of a deadly Aveapon; and it Avas error to lead the jury aAvay from the consideration of these things by instructing them that the mere use of the weapon entitled the plaintiff to their verdict.

Judgment and order reversed, and cause remanded for a neAV trial.