The Supreme Court decided on Monday not to reinstate a contentious Missouri gun law that prohibited police from enforcing certain federal firearm regulations.

The court declined to consider arguments regarding whether Missouri could prevent police from applying federal gun laws that lack similar state legislation.

This law levied $50,000 penalties on officers who knowingly enforced these federal regulations, which pertain to firearm possession by certain domestic violence offenders and the registration and tracking of weapons.

Earlier rulings determined that the 2019 law breached the Supremacy Clause of the U.S. Constitution, which establishes that federal law overrides state legislation.

The justices refused to intervene in 2023, keeping the law blocked while a court fight between the state and the federal government played out.

This disagreement disrupted a law-enforcement collaboration aimed at fighting violent crime after Missouri’s crime lab refused to handle evidence beneficial to federal firearm prosecutions.

Republican legislators who backed the bill were driven by concerns over possible new gun controls under then-President Joe Biden, a Democrat, who enacted the most comprehensive gun violence legislation in decades.