This case opposed the city of Tucson, which took an ordinance allowing for the destruction of confiscated guns, to the State of Arizona, which laws required them to be sold.

In 2000, the Arizona Legislature passed House Bill 2095, which declared:
It is the intent of the legislature to clarify existing law relating to the state’s preemption of firearms regulation in this state. Firearms regulation is of statewide concern. Therefore, the legislature intends to limit the ability of any political subdivision of this state to regulate firearms and ammunition. This act applies to any ordinance enacted before or after the effective date of this act.

That legislation also amended A.R.S. § 13-3108(A) to provide: “[A] political subdivision of this state shall not enact any ordinance, rule or tax relating to the transportation, possession, carrying, sale, transfer, purchase, acquisition, gift, devise, storage, licensing, registration, discharge or use of firearms or ammunition . . . in this state.”
In 2005, the City of Tucson passed Ordinance No. 10146 (the “Ordinance”), which enacted Tucson Code §§ 2-140 to -142. The Tucson Code permits the Tucson Police Department to keep a forfeited firearm for its own purposes or to lend or transfer it to another law enforcement agency or museum; otherwise, the Code states that the police “shall dispose” of unclaimed and forfeited firearms “by destroying” them.
In 2013, the Arizona legislature amended two statutes governing the destruction of firearms. Section 13-3108 was revised to add new subsection (F), which provides: “[A]ny agency or political subdivision of this state and any law enforcement agency in this state shall not facilitate the destruction of a firearm . . . .” And § 12-945(B), contained in an article that governs the disposal of “unclaimed property in [the] hands of [a] public agency,” was amended to state:
[I]f the property is a firearm, the agency shall sell the firearm to any business that is authorized to receive and dispose of the firearm under federal and state law and that shall sell the firearm to the public according to federal and state law, unless the firearm is otherwise prohibited from being sold under federal and state law. Also enacted by the legislature in 2013, A.R.S. § 12-943 provides that certain specified property, including firearms, “in the possession of a . . . city . . . may only be disposed of pursuant to this article.” 

Pursuant to the Ordinance, between 2013 and October 2016, the City of Tucson destroyed approximately 4,800 unclaimed or forfeited firearms. 

In October 2016, Representative Mark Finchem asked the Attorney General’s Office to investigate whether the Ordinance violates state law. The Office investigated, and the City provided public records and a written response. The City contended that the Ordinance was a valid exercise of the City’s “organic law” as a charter city and that the state’s firearms statutes “have no application to the City.”
In November 2016, the Attorney General issued his report, concluding that the Ordinance “may violate one or more provisions of state law” because it requires the destruction of firearms, conflicting with State law, which prohibits any “political subdivision” from “facilitat[ing] the destruction of a firearm.” The Attorney General rejected Tucson’s charter city argument.
After the Attorney General’s Office sent its report to the City, the Tucson City Council met in December and refused to repeal or otherwise change the Ordinance. The City did, however, “suspend the implementation of gun destruction required by [the Ordinance] until the issue is adjudicated.” That same day the Attorney General’s Office filed this special action in [the] supreme court to resolve the issue.
Several days later, the City filed a complaint in Pima County Superior Court, seeking an injunction against implementation of the special action and a declaration that the statute is unconstitutional. The City responded in this Court to the State’s special action petition and also moved to dismiss it. The city argued that this was a local concern, and as such it could regulate it.

But the Arizona Supreme Court sided with the State of Arizona, holding that firearms-related statutes implicate several matters of state-wide, not merely local, concerns and therefore govern over the conflicting municipal ordnance. The court ruled that Tucson does not have the right to ignore state law when it comes to what they do with confiscated weapons.