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 Rhode Island, the criminal offense of unlawful assembly is addressed under Rhode Island General Laws. According to Section 11-45-1, an unlawful assembly can be defined as a gathering of three or more persons with the intent to carry out any unlawful purpose, or in a manner that, if executed, would endanger some portion of the public in their health, peace, or safety. The statute also covers the offense of a rout, which is when an unlawful assembly makes any movement or preparation to carry out the intended unlawful act. Additionally, under Section 11-45-2, if such an assembly leads to a riot, where there is a tumultuous disturbance of the peace by three or more persons assembling together of their own authority, the participants may be charged with rioting. Penalties for these offenses can include fines and imprisonment, and the severity of the penalty often depends on the specific circumstances of the incident. It's important to note that the right to assemble is protected under the First Amendment of the U.S. Constitution; however, this right does not extend to assemblies that are intended to be violent or that pose a clear threat to public safety, peace, and order.