The criminal offense of unlawful assembly generally means the assembly of multiple persons resulting in conduct that (1) is intended to commit a breach of the peace or other unlawful act; (2) creates an immediate danger of damage to property or injury to persons; (3) substantially obstructs law enforcement or other governmental functions or services; (4) is tumultuous or violent and likely to cause public alarm; or (5) deprives any person of a legal right or disturbs any person in the enjoyment of a legal right by using force or the threat of force.

Unlawful assembly laws vary from state to state and some states have related offenses such as rioting, riots and routs, participating in a riot, inciting a riot, failing to disperse, and disturbing the peace. The criminal offense of unlawful assembly may be included in the definition of one or more of these offenses or may be a separate criminal offense. These laws are generally located in a state’s statutes—often in the penal or criminal code.

In Arizona, the criminal offense of unlawful assembly is defined under Arizona Revised Statutes § 13-2902. According to this statute, an unlawful assembly occurs when two or more persons assemble with the intent to engage in conduct constituting a riot, or when they knowingly remain present at an assembly that either has become riotous or poses an immediate threat of becoming riotous. The law also covers situations where the assembly is likely to result in a breach of the peace, or where participants engage in tumultuous and violent conduct that alarms or disturbs others. The offense is classified as a Class 1 misdemeanor. Related offenses, such as rioting, are also defined in the Arizona Revised Statutes, with rioting (§ 13-2903) being a Class 5 felony if it results in damage to property or injury to persons. It's important for individuals in Arizona to be aware of these laws to avoid participating in activities that could be construed as unlawful assembly or related offenses.