Where 12 or more persons who are present together use or threaten unlawful violence for a common purpose and the conduct of them (taken together) is such as would cause a person of reasonable firmness present at the scene to fear for his personal safety, each of the persons using unlawful violence for the common purpose is guilty of riot.
It is immaterial whether or not the 12 or more use or threaten unlawful violence simultaneously.
The common purpose may be inferred from conduct.
No person of reasonable firmness need actually be, or be likely to be, present at the scene.
Riot may be committed in private as well as in public places.
A person guilty of riot is liable on conviction on indictment to imprisonment for a term not exceeding ten years or a fine or both.