Riot (Norman law Lat. riota, riotum; Fr. riotte, a brawl), in law, a tumultuous disturbance of the peace by three persons or more, who have assembled together of their own authority, for the purpose of assisting one another in the execution of some private enterprise, and in resisting any one who shall interfere with or oppose their proceedings, and afterward actually carrying out that purpose in a violent and turbulent manner to the terror of the people. It is wholly immaterial whether the act intended is lawful or unlawful; for it is not the act itself, but the manner in which it is done, which creates this particular offence. Two persons alone may be guilty of a conspiracy, but it requires three to make a riot; and where three persons were indicted for a riot, and the jury found only one of them guilty, it was held that this verdict was void because one alone could not make a riot. Women may be punished as rioters, but infants under 14 years of age cannot. The object of assembling is commonly a private quarrel or wrong; for the proceedings of a riotous assembly to redress public grievances or resist the officers of the king or state may amount to overt acts of high treason, by levying war against the sovereign.

In the latter case, the indictment generally charges that the defendants were armed and arrayed in a warlike manner, and, where the case admits it, with swords, drums, colors, and the like. But the question of riot or treason does not turn singly on any of these circumstances; the true criterion is: With what intent did the parties assemble - whether for a private and particular, or a public and general purpose? Numbers may supply the want of military arms and discipline, as experience has often shown, and such was the opinion of five of the judges in the weavers' case in 1675. In this case the weavers in and about London riotously assembled to destroy certain looms and machinery which had enabled those of their trade who used them to undersell the rest; and the defendants were indicted for treason, but were finally only proceeded against for a riot; the remainder of the court holding that their proceedings did not amount to a levying of war, as the motive was a mere private quarrel between different parties of the same trade, and related to no public or general object.

On the trial of Lord George Gordon, the leader and instigator of the celebrated "no popery riots" in London in 1781, it was the unanimous opinion of the king's bench that an attempt by intimidation and violence to force the repeal of a law was a levying of war against the king. So, too, in the case of Demaree and Purchase, indicted severally in 1719, "for that they with a great multitude of people, to the number of 500, armed and arrayed in warlike manner, etc, did traitorously levy war, etc.,"it appeared that the rabble, with cries of "Down with the Presbyterians," "Down with the meeting houses," etc., undertook by force and violence to carry their threats into execution, and actually did destroy a great deal of property, and resisted the officers sent to disperse them; and the judges agreed that this was a declaration against the " act of toleration," and an attempt to render it ineffectual by numbers and open force, and amounted to high treason. In every riot there must be such circumstances of actual force and violence, or an apparent tendency thereto, as will naturally strike terror into the people; though it is not necessary that actual force or violence should have been committed.

The violence and tumult must also be premeditated; for if they arise accidentally from some cause not likely to produce them, it is but an affray. Thus, if several are assembled together for a lawful purpose and a quarrel happens among themselves, it is not a riot, but only a sudden affray, and none in the assembly are guilty but those who actually participate. But even though the persons assemble in the first instance for a lawful purpose and with peaceable intent, yet they may afterward be guilty of a riot. For instance, if a dispute arise among them, and they form themselves into parties or factions, with promises of mutual assistance, and then make an affray, it is a riot; for the fact of forming such factions or parties and then acting with a definite and unlawful intention is constructive evidence of premeditation. If three or more persons, lawfully assembled, quarrel among themselves, and the party falls upon one or more of their own number, this is a simple affray; but if they attack a.stranger, the very moment the quarrel begins it becomes an unlawful assemblage, and it is a riot in all those who join the affray, but only in them.

So a person seeing a riot and joining therein becomes a rioter himself, though he did not go there premeditating the act, and is liable as a principal with the rest. The inciting persons to assemble in a riotous manner is also indictable. The law will not allow individuals to seek redress for private grievances by disturbing the public peace, though in some cases the justice of the quarrel in which they are engaged may be a great mitigation of the offence. - By the common law, riots were punished by fine and imprisonment, and if enormous by the pillory. But these penalties being found insufficient, statutory provisions were early made for their suppression. The first English statute enacted for this purpose was 34 Edward III., c. 1, E. II., which gave justices of the peace very extensive authority in such cases, and visited the offence with severe punishment. The statute 1 George I., commonly called the "riot act," made it a capital felony for persons riotously assembled to the number of 12 or more to continue so assembled for one hour after proclamation by a justice of the peace requiring them to disperse; thus leaving the offence, if committed by more than 3 and fewer than 12 persons, punishable by fine and imprisonment only, but if by 12 or more by death.

Subsequent statutes made other specific offences felonious, such as riotously demolishing any church or chapel, or any house or other building, or any machinery or manufactory, or forcibly obstructing the export of corn from any part of the kingdom. Principals in the second degree and accessories before the fact were also punishable as felons. In the United States the statutory provisions respecting riots follow in a great measure those of England, but are milder in their punishments and more qualified in their application.