The act by which a party accused shows and maintains a good and legal reason in court, why he did the thing he is called upon to answer.
What Acts Are Justifiable.
The acts to be justified are those committed with a warrant, and those committed without a warrant. It is a general rule that a warrant or execution issued by a court having jurisdiction, whether the same be right or wrong, justifies the officer to whom it is directed and who is by law required to execute it, and is a complete justification to the officer for obeying its command. But when the warrant is not merely voidable, but is absolutely void, as for want of jurisdiction in the court which issued it, or by reason of the privilege of the defendant, as in the case of the arrest of an ambassador, who cannot waive his privilege and immunities by submitting to be arrested on such warrant, the officer is no longer justified.
A person may justify many acts, while acting without any authority from a court or magistrate. He may even justifiably take the life of an aggressor, while acting in the defence of himself, his wife, children, and servant, or for the protection of his house, when attacked with a felonious intent, or even for the protection of his personal property.
A man may justify what would otherwise have been a trespass, an entry on the land of another for various purposes; as for example, to demand a debt due to him by the owner of the land to remove chattels which belong to him, but this entry must be peaceable; to exercise an incorporeal right; ask for lodging's at an inn.
It is an ancient principle of the common law that a trespass may be justified in many cases. Thus, a man may enter on the land of another, to kill a fox or otter, which are beasts against the common profit. So, a house may be pulled down if the adjoining one be on fire, to prevent a greater destruction. So, the suburbs of a city may be demolished in time of war, for the good of the commonwealth. So, a man may enter on his neighbor to make a bulwark in defence of the realm. So, a house may be broken to arrest a felon.
In a civil action, a man may justify a libel, or slanderous words, by proving their truth, or because the defendant had a right, upon the particular occasion, either to write and publish the writing, or to utter the words; as when slanderous words are found in a report of a committee of congress or in an indictment, or words of a slanderous nature are uttered in the course of debate in the legislature by a member or at the bar by counsel, when properly instructed by his client on the subject.
In general, justification must be specially pleaded, and it cannot be given in evidence under the plea of the general issue.
When the plea of justification is supported by the evidence, it is a complete bar to the action.