At the Law Office of Daniel Hutto, our criminal defense attorneys have the experience it takes to win an unlawful possession of a firearm case in Arizona. It is unlawful to carry a firearm concealed within the immediate control of any person in or on a means of transportation if under 21 years of age.ARS 13-3107, also known as unlawful discharge of a firearm in Arizona, is a serious offense with significant legal consequences. Learn what the law says. Defenses to the Unlawful Discharge of a Firearm. The law has four felonies for unlawful possession, Class 2, 3, 4, and 6. A class 6 felony is the lowest in the felony architecture. Arizona Revised Statute 133107, otherwise known as Shannon's Law, is the state's law prohibiting the unlawful discharge of a firearm. Being a prohibited possessor is a felony. Prosecutors take any gun crime seriously.