A previous agreement or conspiracy to riot is not usually an element of a riot. A common intent, however, to engage in an act of violence, combined with a concert of action, is sometimes necessary. In one case, following a high school football game, a group of boys staged a "violent, brutal and indecent" assault on the color guard and band members of the visiting team. When the visitors attempted to leave, the attacks continued. On trial, the attackers claimed that the charge of riot did not apply to them because they had had no "common intent." The court held that "an intent is a mental state which can be inferred from conduct." They were found guilty of riot and the decision was affirmed on appeal.
Law Library - American Law and Legal InformationFree Legal Encyclopedia: Reputation to Owen Josephus RobertsRiot - Nature And Elements, Riotous Conduct, Common Intent, Terror, Suppression Of Riot - Number of Persons Necessary, Purpose of Original Assembly, Persons Liable, Municipal Liability, Defenses