Riot defined

(1) If five or more persons together in any public or private place commence or attempt to do either of the following things, namely150 (a) to execute any common purpose with violence and without lawful authority to use such violence for that purpose; (b) to execute a common purpose of obstructing or resisting the execution of any legal process or authority; or (c) to facilitate by force or by show of force or of numbers the commission of any crime, they are guilty of a riot. (2) Persons are not guilty of a riot by reason only that they, to the number of five or more, suddenly engage in an unlawful fight, unless five or more of them fight with a common purpose against some other person or persons.