common object Existence of a common unlawful object is a requisite for a unlawful assembly under the PENAL CODE (Revised 1997) section 149 comes in. In order to determine the common object of an assembly, circumstances of the case, attitude the deportment of the persons assembled very often furnish key to their mental bent. A person who encourages or promotes or takes part in rioting whether by words, signs or gestures or even by wearing the badge or ensign of the rioters becomes a rioter, for in this case all are deemed principals. On the other hand, and mere presence without encouragement is not enough to establish criminality.