A public disturbance involving (1) an act or acts of violence by one or more persons part of an assemblage of three or more persons, which act or acts shall constitute a clear and present danger of, or shall result in, damage or injury to the property of any other person or to the person of any other individual or (2) a threat or threats of the commission of an act or acts of violence by one or more persons part of an assemblage of three or more persons having, individually or collectively, the ability of immediate execution of such threat or threats, where the performance of the threatened act or acts of violence would constitute a clear and present danger of, or would result in, damage or injury to the property of any other person or to the person of any other individual. 18 USC
At common law a riot is a tumultuous disturbance of the peace, by three persons or more assembling together of their own authority, with an intent, mutually to assist each other against any who shall oppose them, in the execution of some enterprise of a private nature, and afterwards actually executing the same in a violent and turbulent manner, to the terror of the people, whether the act intended were of itself lawful or unlawful.
In this case there must be proved, first, an unlawful assembling; for if a number of persons lawfully met together; as, for example, at a fire, in a theatre or a church, should suddenly quarrel and fight, the offence is an affray and not a riot, because there was no unlawful assembling; but if three or more being so assembled, on a dispute occurring, they form into parties with promises of mutual assistance, which promises may be express, or implied from the circumstances, then the offence will no longer be an affray, but a riot; the unlawful combination will amount to an assembling within the meaning of the law. In this manner any lawful assembly may be converted into a riot. Any one who joins the rioters after they have actually commenced, is equally guilty as if he had joined them while assembling.Secondly, proof must be made of actual violence and force on the part of the rioters, or of such circumstances as have an apparent tendency to force and violence, and calculated to strike terror into the public mind. The definition requires that the offenders should assemble of their own authority, in order to create a riot; if, therefore, the parties act under the authority of the law, they may use any necessary force to enforce their mandate, without committing this offence.
Thirdly, evidence must be given that the defendants acted in the riot, and were participants in the disturbance.