And St. Louis County could opt out of the law by changing its form of government, the appeal says.

The municipalities also appealed aspects of Beetem’s ruling, asking whether the law violated the state constitution’s “separation of powers” provision by giving the state’s director of revenue the authority to force a municipal court to cede its jurisdiction to the state court.

The municipalities also ask whether the law is inconsistent with procedural rules for criminal prosecution, and if so, whether it violates the constitution.

“It’s an important case because it clearly will help set the precedent for how the legislature looks at handing down requirements,” said Patrick Green, mayor of Normandy, one of the plaintiff cities.

Two groups filed briefs in support of the state’s appeal.

The American Civil Liberties Union argued that the law’s focus on St. Louis County and its municipalities was constitutional and “because of the abusive policing and municipal court practices inflicted upon Missourians by municipalities in St. Louis County” would be justified.