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 Iowa, the criminal offense of unlawful assembly is addressed under Iowa Code Section 723.2. According to this statute, an unlawful assembly occurs when three or more persons assemble together to commit any unlawful act, or to do a lawful act in a violent, boisterous, or tumultuous manner, such that it is likely to disturb others. The law is designed to prevent disorder that threatens public peace and safety. Penalties for participating in an unlawful assembly can include fines and imprisonment. It's important to note that the right to assemble is protected by the First Amendment of the U.S. Constitution, but this right does not extend to assemblies that are violent or that pose a clear threat to public order. In addition to unlawful assembly, Iowa law also addresses related offenses such as rioting and failure to disperse, which are outlined in separate sections of the Iowa Code. An attorney can provide more detailed information about these laws and how they might apply in specific situations.